 Full moon check. City light pollution? Check. Super small telescope. Check. We have all the exact wrong conditions to capture a galaxy, so let's see what we can do. Hello and welcome to my YouTube channel. My name is Nico Carver. I am an amateur astrophotographer and I like to make videos like this one to help beginners who are interested in astrophotography get started with some tips and tutorials. If you're new to this channel, please subscribe by pressing the red button right below this video. And for those returning, I'll just mention briefly here that I do have a Patreon that starts at just $1 a month. And I truly appreciate the support. It really helps me make these videos today. I'm going to show you every step of capturing a galaxy with your DSLR or mirrorless camera. And as the intro suggested, I'm going to do it with some difficult starting conditions. Normally for capturing a galaxy, you want a large telescope with plenty of focal length to resolve detail, because galaxies are pretty small from here on Earth in terms of their size in the sky. And you want to shoot normally on a moonless night from a dark site to improve the contrast of the image because due to atmosphere and light pollution, we're always trying to improve that contrast of the deep sky object. Well, we're doing the opposite of all those things, not just to be contrary, but for sort of two reasons. One, I find it fun to test the limits of my equipment and processing skills. And I also hope that you get something out of it by seeing how to process images when we're starting with conditions that are not so great. How can we subtract really heavy light pollution gradients and deal with the noise of heavy light pollution with a small telescope? And number two, I hope that this inspires people to try shooting galaxies with whatever gear they have. You don't have to feel like you need to get the perfect scope and mount even with just a zoom lens on a simple star tracker. You should try this. I think that you really might be shocked at what you can do. I was definitely surprised by results I've gotten with small telescopes. And lastly, for an intro here, this video is part of my start to finish series. It's something I'm trying out. And what that means is it'll be a pretty long video because I'm going to show you every step of the process. We're going to start here in the house and I'll explain the equipment that I'm going to use. And a few of the ins and outs and considerations when thinking about what equipment to buy and things like that, and what different pieces of equipment do, what they're good for. And I also just wanted to note here, it's a really good idea to sort of take stock of your equipment and make sure you understand how it all works indoors. And you do that so that you really get to know your equipment before you bring it out into the dark because everything gets so much harder outside in the dark. After we look at the equipment, I'll show setting it up outside, which includes just putting it all together, focusing the telescope on a bright star, finding the galaxy. The galaxy is going to be invisible to us and the camera because of the light pollution, but we'll use a technique called star hopping to find it. And then we'll start capturing our lights. And if you're new to astrophotography and you hear that term capturing our lights or light frames, that just means our actual photos of the night sky. And with deep sky astrophotography, we take hundreds of the same spot in the night sky. And the point of this is because when we get to the processing stage, which I'm going to show in this video, we're going to stack them all together in software. And by stacking them all together, you know, let's say 532nd exposures, that turns into one super exposure. So about five hours of total time. And by combining all those short exposures together, what we're doing is through stacking is we're reducing the noise in the picture. And by reducing the noise, that's what will make the galaxy all of a sudden stand out. So in a single light, we're not going to be able to see the galaxy will be invisible to us because of that light pollution. But after we stack them all together and subtract the light pollution, the galaxy will stand out because we've reduced the noise and done some other processing. In addition to lights and remember lights just means your photos of the night sky, I'll also show taking calibration frames. And those are called darks, flats, and bias frames. And I'll explain later what each of those terms means. Once we have all of those pictures, and astrophotographers will often call all of our pictures as one big thing, our data. So all of the pictures put together as our data, and we compile it all, we compress it down into one single picture, but one single astrophotograph is actually made up of hundreds and hundreds of lights, darks, bias, and flats. And we're going to take a look at each of those types of pictures, the lights, meaning the actual photos of the night sky and the three calibration frames in their raw state. So you can see what they look like, and we'll talk about what they do. Then we'll move on to processing those pictures. And there's sort of two stages in processing. There's the pre-processing, which is the calibration registration, which means taking all your pictures and matching them up based on the star pattern. So they're all exactly aligned. And then stacking, which again is is taking tons of exposures and making them down into one, and reducing the noise by throwing out outliers like hot pixels and things like that. After we're done with that pre-processing, which in this video we're going to use Deep Sky Stacker, which is a free Windows program, we'll move on to Photoshop. And Photoshop, Adobe Photoshop is a really popular program for post-processing of all kinds of photography, including astrophotography. I'll have some other videos, though, below this one. They might not be available right away, but within a week or two, that show the other programs that you could do this with. So if you're interested in a different program, not Photoshop or Deep Sky Stacker, watch the first half of this video and then move on to one of those other videos. And I'll have one video that shows the whole thing in Pix Insight, just a paid, more advanced program. I'll show one that's Deep Sky Stacker plus GIMP, the GNU Image Manipulation Program, which is a free open source Photoshop alternative. And because Deep Sky Stacker is Windows only, for the first time due to popular demand, I'll also show a workflow in Cyril and GIMP for all you Mac owners who want to use free open source software for your image processing. Okay, so that's the overview. As a beginner video, though, I'm going to be using fairly affordable gear. And I'll also keep all of my capture techniques and my processing techniques as simple as I can. Now, the processing techniques with this one might be a little bit crazier because of our difficult starting condition. So we're going to have to do a little bit more, maybe working with channels and different things in Photoshop to tease out this image and reduce the noise. But I'm still going to try to keep it understandable. Astrophotography can get really complicated really fast. But I want to emphasize that we can still take beautiful photos with the more affordable gear and even free software. Okay, so let's break down what I'm going to be using tonight. We'll start with this. This is the mount I'm going to use. It's the Ioptron Smart EQ Pro. And this is a very lightweight mount. The way you know that is because I'm lifting it up with one hand. With most astrophotography equatorial mounts, this wouldn't be possible. The way they made this possible is that this mount is mostly plastic. Having a lot of plastic parts, it also makes it a fairly inexpensive computerized equatorial mount. It goes for around $500. The cons are of course that plastic pieces don't hold up to as much use and abuse. You can see here I recently broke the battery door. Might have been partly my fault because I had some stuff hanging on it. So it wasn't really designed to do that, I guess. And I put too much strain on that. But now it's just taped on. What these battery doors do is they're just a cover for the AA batteries inside. But there are lots of pieces with this. We'll also see on the tripod, the tray on the tripod is also held in just by sort of like a plastic pressure clip like that. And with any kind of plastic pressure clip, there's a good chance it will break eventually just from using it too much. That's a downside. The other major con with a lightweight mount like this is you just have to be really aware of how much weight you're putting on it. And to succeed with this kind of mount, you really need to keep the weight well below the advertised limit. And even with a light payload, like I'm going to be trying to use, this mount will not be as accurate as a beefier, more expensive mount like my Skywatch or EQ6R, something like that. So I want to emphasize this. If you have the money, definitely get a better mount. I would say the accuracy of the tracking on this is comparable to a Star Tracker style mount, you know, those ones like Skywatch or Star Adventure that only track and write ascension. The reason, though, to possibly spend a little bit more money to get one like this over a Star Tracker package is that it's a bit more optimized to accept a small telescope out of the box. This is a saddle for a Vixen Dovetail. It also has, you know, the internal counterweight shaft. You don't have to clamp it on or anything like that. Very handy. Put the counterweights on, balance very quick. I know a number of Star Trackers now have internal polar scopes, but they don't all have them. This one does have it. And then, of course, the thing that really separates it from most Star Trackers is that it's go-to. So I can connect a hand paddle here and go-to objects. I could use this same port to connect to a computer and control it from my computer. That's sort of really what separates it. It's really, though, not necessary to follow along with this tutorial. So if I get to a part where I'm using a hand paddle and you're not using this kind of thing, you're just manually pointing perfectly all right. This is really an optional piece. So that's the mount. This is the scope that I'm going to be using. And as you can see, this is a really small telescope. It's the Astrotech AT60ED. The 60 refers to the fact that it has a 60 millimeter front aperture, which is quite small. I have many camera lenses that have a larger front aperture than that. But the nice thing about a small doublet design like this, a doublet means that there's only two pieces of high quality glass in here. And by having only two pieces of glass, it really keeps the weight down. And I should say there's a couple of more pieces of glass in the field flatener, which I really do recommend. I think the scope goes for a bit under $400, but then once you add on the camera angle adjuster, which lets you rotate and the field flatener, it's about 500. But you really, these really sort of make it an astrophotography scope. So if you're planning on buying something like this, definitely get the field flatener too. That's what without this, it means that your stars along the edge will all be misshapen with the field flatener, you'll get much better stars out to the edge. Maybe not all the way out to the edge of a full frame sensor, like I'm going to be using today, but I'm planning to crop anyways, so it shouldn't matter too much. Anyways, other companies make a version of this same scope at similar prices. So if astrotech or astronomers is sold out, you can find it elsewhere. And some of you might be asking, why are we using this telescope when I do have other telescopes that would be better for photographing a galaxy? Well, for one thing, I really like a challenge and to see what can be done with smaller scopes and even camera lenses. And also, since this is a beginner video, I don't want to jump into using a big Newtonian because due to the weight and the size of a Newtonian, it really requires a very stable mount to get good results, like a mount that's at least $1,000. So even with a six inch newt, very expensive, works pretty well. When you consider the mount and the coma corrector and the collimation tools and all that, there's just so much to buy and to learn about to get imaging with that. So this is much easier, especially if you are... I've started with the photography world. You're used to using lenses. This is basically like a lens. It just works a little bit better for astro photography. It has a really nice accurate focuser that can hold some weight and will stay in one position. It has some mounting brackets if you want to mount stuff to it. So it's really just like a really nice camera lens that's quite the deal for 360 millimeter focal length at this price point. But I'll mention here that no matter what kind of gear you're using, feel free to try to follow along with this tutorial. Of course, galaxies other than Andromeda and the Magellanic Clouds are pretty small in the night sky. So the more focal length you have, the better. Once you get to this higher focal lengths like 300 millimeters or more, you really need a tracker or a mount to track the night sky. So there is some gear considerations here. But if you already have a telephoto lens, you already have a star tracker. Don't feel like you need to run out and buy a telescope right away. See what kind of results you can get with the gear you have first. To connect my camera to this telescope, I'm just using a generic T adapter designed for Canon cameras, Canon DSLRs. And since this is a full frame camera, I'm using a 48 millimeter T ring rather than the more standard 42 millimeters, which would be fine for crop sensors. The usual reason to use the wider T ring is to get less vignetting when using a full frame camera. Anyways, the camera is my Canon 5D Mark III. It's not modified. That's a question I get a lot. And by that, I mean, some people will modify their camera by replacing the stock UVIR cut filter, the one that comes with the camera, the one that lets in a little bit more of the red spectrum to get better response for H-alpha emission lines. For galaxies, this typically doesn't matter so much anyways. There are H-alpha regions in galaxies, but they're not the focus. Galaxies are thought of as broadband targets, meaning lots of colors, blues, yellows, all that kind of stuff. And because they're made up of individual stars and stars range in color from blue to red. The reason though to do a modification of your DSLR, I'll probably have videos on this later, is if you're shooting a lot of red nebulae, those HA and sulfur emission nebulae, it does make a difference. The DSLR I'm using, the Canon 5D, doesn't have a built-in intervalometer. Intervalometer is just a term, a fancy word for a timer. You see that the word interval is at the front of it. And so it's basically an interval timer. It allows you to take time shots every so often and you can do a sequence of shots without having to ever touch your shutter. An intervalometer also typically can act as a bulb timer, meaning that if you're doing longer shots, like five minute long exposures, it can count that down and basically hit the shutter release, send a command to the camera at the right time. There are a lot of different options here, and people have been pointing them out in my comments a lot. One that I haven't mentioned in the past is a lot of new cameras have apps that you can use. So Wi-Fi or Bluetooth apps that can do this. Another option is we can tether our camera with a USB cable to a laptop out on the field and use software like some of them I know that are, some that I know are backyard EOS if you're using a Canon camera or backyard Nikon if you're using Nikon or something like astrophotography tool. And those can act as an intervalometer and a lot more too. Another option is an external intervalometer and I've showed this in past videos basically you buy a little device and connect it to your camera and that can work. Tonight I'm not going to be using any of those. I'm going to be using an internal intervalometer and I know a lot of you might be thinking well in past videos he said his Canon 5D doesn't have that. Well I'm going to be using a firmware hack called Magic Lantern and so if you're not a Canon DSLR user you may want to skip ahead a few minutes because this is only going to apply to older Canon DSLRs that can have this firmware hack put on them. But basically what it is is some developers have released these, this thing called Magic Lantern for free. It's supported on about a dozen older Canon DSLRs. I am not responsible if something happens to your camera so I'm just telling you this information but I don't hold me responsible if anything happens. With that said what you do is you go to builds.magiclantern.fm if your camera is supported it'll be on that page you can then download the zip file follow the installation instructions that will be right on the page there and it usually just involves copying the files to your SD card running the firmware update and after that when you turn on your camera again you have Magic Lantern. The way to access it is you just press the trash button you'll see all these Magic Lantern menus including the shoot menu where there is now an intervalometer. Okay so to just go over the options one more time connect to a laptop connect to a smartphone if your camera supports it use an internal intervalometer if your camera already has one if you have an older Canon DSLR you can hack the firmware to get one or lastly and maybe most simply just buy an external intervalometer very simple devices that work really well. But tonight I'm going to be using Magic Lantern because a lot of people in the comments sections and past videos have told me that they want to see this and it's it's firmware that I think is quite stable I've been using it for years so we might as well check it out. Okay then that's the camera again Canon Vive Team R3 but it doesn't matter what camera you're using as long as it can shoot raw as long as you can take long exposures go for it. Next piece of equipment though is a finder device and the point of a finder device or a finder scope is to tell you where your camera is pointed at in the night sky and some of you may be thinking well why not just use the camera itself why not just put on live view and it will tell you where you're pointed. Well the issue with that is once you get passed around let's say a hundred millimeters and focal length this can be really difficult to do because a lot of times our deep sky object isn't near any bright stars that are going to be in the field so you try to move to where you think it is and you have no idea because it just looks like a bunch of random stars. Many star fields are pretty indistinct I take a photo of it I don't recognize any star patterns you can try to look in you know an app on your phone but it's often very difficult and so this is where a finder is very helpful they're all designed basically the same way they offer a wider field of view than you're getting in the eyepiece or your camera and often some kind of indicator like a dot or a target or a crosshairs that shows you where you're pointed in the night sky then all you have to do is just move that finder around until you know that you're pointed in the right spot as long as it's aligned with your main telescope or your lens and the camera then you know you're pointed in the right part of the sky so I'm going to go over some of the major types here of finder scopes this one this is a right angle corrected image finder scope and it's my favorite for visual astronomy but not my favorite for astrophotography the way that this works is it's purely optical the reason I like it for visual is with when I'm using it with like a dob like the one behind me I like to keep things completely optical no electronics it's really fun just to push things around and know everything you're looking through is just glass or mirrors basically the way this works though it has this little built-in prism with a little crosshairs eyepiece and you just look through it and line up your object since I live in a really light polluted area here right near Boston I mostly use my dob with this finder to view the planets and the moon and since those objects are really bright the finder scope is perfect for just looking down casually pushing the dob over a little bit till it's centered and then I can look back in the eyepiece and know they're Saturn again right so it's really easy this though for astrophotography I don't find very useful the field of view on this isn't very large and you're looking through it like this usually with one eye closed and so I don't find that it offers much advantage over just using live view on the camera and we've already talked about why that has some problems when you're looking for hard to find deep sky objects so don't recommend this for astrophotography but if it's all you have you can try it next type of finder is a telrad this device is battery powered I think it's one or two double a's and the way that it works is it basically through a little mirror in there puts a red target right on top of the sky so you can just actually look through it and you don't even need to close an eye you can look through it with both eyes open and as long as they are at the right angle you'll see a red target right on the sky and you're also getting your whole you know your whole vision's field of view as you're looking through this so this is really nice I can use it to star hop using bright constellations and the the red target is also adjustable right here you can change the intensity of it right there the downside to a telrad is it's so large you probably wouldn't use it unless you're using a telescope and have a place to mount it like a finder shoe on a focuser like this so for camera lens setups I have two more options the first one is the cheaper option this is called a red dot finder it's the exact same idea as a telrad but instead of a full target you just get a single red dot to indicate where you are pointed the last time type of finder and the one I'll be using tonight is a green laser finder and the way this one works is it's just a green laser that's really all it is and it's probably the most dangerous type to use you don't want to shine this in someone's eyes of course but since it's quite powerful check with your local authorities make sure you can use this they're banned at most star parties on most observing fields because they can be a nuisance if you're doing astronomy with other people and you also have to be super careful not to use them when an airplane is passing overhead because they have the potential to blind the pilot or passenger if they're looking out the window or if you shine it right in the front cockpit so if you see a plane stop using it if you understand those safety precautions it is a really nice finder because it is very clear where you're pointed and what I really like about it is at night you can actually see the green laser beam all the way from the the laser itself up into the sky like it like you see the solid laser beam and so it just makes it really clear exactly where you're pointed in the sky this one just connects right on to my DSLR hot shoe with any of these finders you have to make sure that it's adjusted to be pointing at the same spot as the DSLR or it's basically useless and what they all have for that is a little adjustment knobs and so the way I usually use this is I do a rough alignment inside so I'll just shine the laser against a wall see that the laser beam is roughly centered on screen on my DSLR then when I get outside I'll do a finer alignment using Polaris the north star so after I do my polar alignment I'll look on the camera's LCD I'll see the Polaris is centered and then I'll shine the laser on it and then adjust my laser until it's right on Polaris and then I know the camera and the finder are aligned and I can trust what I'm seeing with the finder is the same place that the camera is pointed okay next piece of equipment and I'll be talking more about this when we talk about calibration frames in a second here is some kind of white illuminated panel or source of white light like a white wall that's very even to take your flats I'm going to be using the Pegasus Astro Flatmaster but it's not necessary to buy something for this just you can just sort of use your imagination try to get a very flat field and make sure that it's very flat against the front of your lens or telescope so one thing I've done in the past that works pretty well is just get like a drawing app for an iPad or a laptop just put your telescope or camera lens like that and then just put this right on top and take your flats it's the exact same idea with the flat panel the flat master but this is if you already have something again like a laptop or an iPad or something like that just use it the important thing is just to get it very flat against the the front surface and that it's evenly illuminated as best you can you can also get led tracing tablets that work really well I have one of those two and I'll put a link in the description this piece of equipment is optional but I recommend it it's a Bodinov mask you can make these yourself I have a video about that if you're interested or you can buy them for usually under $20 and they just go in front of your scope or lens and what they do is they create a diffraction pattern based on this with really bright stars it makes this sort of x shape with a center line and you just sort of then it's very easy just to focus so that that center line is in the middle of the x and that's the confirmation that you're truly in focus at infinity on the stars unfortunately we can't just focus on something far away during the day unless you're sure that the temperature is very stable because when temperature shifts so do the glass elements in a lens or telescope and that shifting of the expansion or contraction of the glass is what can change the focus as the temperature changes so ideally you really even should check focus a few times during the night let's say every half hour every hour to make sure that it hasn't shifted the last piece of equipment may also be optional it really depends on the season your location a few different factors but if you're if it's spring or summer you really might need this especially if you're in a human place it's a dew heater band here's an example of one this is a dew no this is an astro zap I also use do not heater bands and basically you need the dew heater band you connect this around the front element of your telescope or your lens and it keeps that front glass element a little bit warmer than the ambient temperature and that prevents dew from forming on it the reason to prevent dew is of course because if you get dew on your lens your picture is going to get all blurry from the the water vapor and the condensation on the lens the thing I don't like about having one of these with a setup like this one is without it I wouldn't have any cables running off the mount the more cables you have running off the mount the more things that can go wrong but if you just have this one cable it should be okay as long as you just make sure it's not snagging on anything the way I have this running is just to a little home built a dew heater controller a friend built for me and then that's running down to this kind of thing and then I have a little lithium ion battery pack for powering it this setup is okay especially if you are running more than one dew heater band but if you just need one what I recommend is getting something like this this is a kuwu usb powered uh dew heater band it's pretty simple um it just has three settings low medium or high and it's pretty inexpensive and it just again is powered from usb so you can just use like your laptop or a cheap power bank like this that is good for like powering a smartphone so multi-purpose you just plug it in and works really well really the only reason to get the more advanced dew heater controller is if you're mul or again running multiple dew heater bands like one for your guide scope one for your main telescope so the major types of calibration frames again are bias darks and flats bias is probably the simplest you can take them once and use the same bias frames for all your projects because they are just camera specific they have nothing to do with any other conditions um basically they are just the noise that's inherent to your sensor called the fixed pattern noise um and so uh the way to take a bias frame is just set your camera's shutter speed to as fast as it possibly can go so on most cameras that's either one four thousandths of a second or one eight thousandths of a second and take 50 of them you stack them all together and you have a master bias frame and again you can just do that once and then keep reusing it that's bias master dark is a oh and i should say about master bias sorry um it's you you want it to be completely dark so you can just put the body cap on your camera take it in a closet take it in the dark at the same iso you normally use let's say iso 800 and you have your bias frames dark same thing put the body cap on the camera take it in the dark but we want to also match the shutter speed of our lights again lights are the pictures of the night sky and we want to match the temperature that we took our lights at because the main thing that the darks do is they are to take care of thermal noise by subtracting it from the lights and so thermal noise is the noise that builds up due to the sensor being warm and so if you're shooting in a really cold place darks are less necessary but the warmer it gets the more darks are important but i just would recommend shooting them anytime and they'll also take care of other sensor peculiarities like amp glow and hot pixels and all these kinds of things that i won't explain right now but are annoying when you see them hot pixels basically show up as these bright red green or blue all the way saturated all the way really bright pixels that are quite annoying to see flats are to correct any dust that's either on the lens or anywhere in this system so you could get dust on your field flattener you can get dust on your camera's sensor you can get dust almost anywhere it's also to correct vignetting to some degree some vignetting is still going to be there probably but flats help correct it they're often a little bit more challenging than dark for bias but i recommend you start practicing now even if you're a beginner astrophotographer i recommend doing flats they're pretty important the way that we take them i've already said a little bit in the equipment section is we just put something flat against the front of the scope or point it very flat flat on at a an illuminated wall or something like that and what we're trying to do when we take these is we want to meter or use the histogram to get a fairly even exposure so a little bit under is better than a little bit over i would say so if you're using the meter you can just you can either just meter exactly in the center or a little bit under i wouldn't go over because you don't want to overexpose your flats but a flat that's a good exposure is usually somewhere if you're looking at the histogram the histogram peak should be somewhere around one-third to one-half over from the left and that's your your shutter speed time the iso should be the same as your everything else so keep the same iso for everything the shutter speed for the flats should be so that the exposure is about midway over in my case with a bright source like the flat master that's like a very small fraction of a second so usually with a dslr and a bright white light source it's going to be a small fraction of a second so they're very easy to take take about 30 i mean to start in the q menu here which is the q stands for quick menu on the canon 5d it looks like this and it just lets you set a number of settings quickly i'm going to be taking 30 second exposures tonight i know for my sky's 30 seconds is the most i can do at iso 800 you may find that with your skies you want to change this or with your camera and a different iso sighting setting might be better for your conditions but usually on most cameras especially canon cameras you you want about 800 to 1600 um that sort of is a trade-off between read noise and dynamic range on some newer cameras include especially ones with sony sensors you might be able to go down to a lower iso and still get a good trade-off and get a little bit more dynamic range in your shot for my camera though 800 is good um so 30 seconds iso 800 initially here um since i want to take some test exposures i'm going to change it from single shooting to self timer two seconds and what that means is that after i hit the shutter button it will wait two seconds before taking the exposure and then that way i can use the shutter button so it's a little bit quicker um but it will also let me uh avoid too much shake from hitting that shutter button okay so that's all i have to really do in the quick menu i want to use my main memory card the bigger one so it's already set that way it's already set to raw but we'll see a little bit more about that in the main menu of the camera okay now we're in the main canon camera menu system just the one you get by hitting menu and this may look a little bit different than your camera if you're not using a canon camera but uh hopefully you'll be able to find all of these settings or at least most of them as you're going through your menus and setting it up for astrophotography the first thing we're going to start with here is image quality and you don't need to use the jpeg settings unless you want to turn that on to have a jpeg backup but it's really not necessary because we're only going to be using the raw setting so i just want to use the full raw setting no need to uh have a jpeg equivalent um if your camera for some reason only shoots jpeg and not raw then just use the highest quality jpeg uh available okay image review i am going to turn off um we could turn it we could leave it on for the initial uh testing stage of you know taking our initial test exposures to nail focus and things like that if you find it useful but usually i need more than even eight seconds to look at one of those test exposures and i need to zoom in so both of those things i need to do in playback mode so i'm just going to leave image review off we definitely want it off when we actually start our round of exposures because um every time it uh enables the lcd that's going to heat up the camera and also have the possibility of causing straight light so we want to turn it off beep i'm also going to disable because i don't need sound um release shutter without card it doesn't really matter we just want to make sure we do have an sd card inserted uh we're not using the lens we're using a telescope so i'm going to leave that off but if you were using a lens this can be useful to turn on the lens uh vignetting correction speed light control is about external flash we don't have to worry about that mirror lock up this is useful if your camera does have it what this does is it locks up the mirror before it takes an exposure if you do enable it just keep in mind that you're going to have to um let a little time elapse between exposures for it to lock up the mirror um so i would maybe allow a few seconds for it to do that uh you can you can also just leave it disabled and allow those few seconds between exposures to try to avoid camera shake as well so it is nice to have i would recommend enabling it if you have it but it's not absolutely necessary if you don't see it okay um most of this uh is about color um and most of it doesn't really matter if you're shooting raw but if you are shooting jpeg i would recommend daylight white balance or doing a custom white balance during the daylight um with a gray card but usually daylight white balance works fine for night sky stuff okay picture style again that's a jpeg transformation thing you can just leave it on standard doesn't matter um long exposure noise reduction i would recommend turning off if you're following along with me because we're going to take darks ourselves if you don't want to take darks what this does if you enable it is it will take a dark immediately after you take your light and subtract it from the light um it's not the way that i work but some people do so just so you know what that does it takes longer um while you're under the night sky and because i have so few clear nights i usually turn it off and take my darks on a cloudy night uh so that i get as much night sky time as possible high iso speed noise reduction turn off um a lot of these settings i'm not sure if they're really going to affect us in raw mode but i would just recommend turning all of these things off live view shooting exposure simulation all these things enable because i think they help you see the night sky better when you are framing things up all this is about autofocus we can't use autofocus unless we're like you know maybe on the moon or something like that uh for most cameras that are not going to be able to autofocus on the stars so it really doesn't matter and we're going to be using a telescope so autofocus doesn't apply to that either um all of these are about playback stuff so again doesn't really matter uh here i would always recommend formatting your card uh before you start i'm using a fairly big card here uh so i don't need to do it right now but if you were for instance using like a 32 gigabyte card uh you might fill that pretty quickly so i would recommend backing everything up and formatting before you get out under the night sky so you have plenty of room to take your pictures and don't have to worry about filling it up okay auto rotate i would recommend turning off once in a while i have seen this confuse image processing software especially the stacking software when you have auto rotate turned on because uh basically the it's then recorded in the raw file which way the camera is rotated and the the imaging software might read that in and think that two pictures have um are incompatible because one's in landscape mode and one's in in portrait mode or something like that so i would just recommend turning it off and then you won't run into any of those problems auto power off i usually disable that um it's really up to you uh but i don't i don't find it uh helpful because like when i'm out on the field i don't want to be doing something and then have to turn the camera back on because it turned it off automatically so i usually disable that okay i don't think any of these other things matter so i think we've gone through all the menu settings that matter for astrophotography um next i'm just going to quickly show you um magic lantern um which is a whole other set of menus um but with them we'll use it more out on the field okay here's magic lantern it has a whole other set of menus some of these settings we've already seen in the quick menu like the shutter speed and the iso and some of these settings we saw in the more advanced canon menu so some things are repeated but then many settings in here are uh unique to magic lantern um so being able to set up different uh displays and things like that um most of these uh are not particularly important to astrophotography uh again this is the the movie settings so we're going to skip over those here's the shoot settings and this is where we're really going to use magic lantern tonight which is this intervalometer setting right here um and you can turn it on just by hitting the set i already have it set up to sort of uh be how i want it tonight um well except for the how many shots it's going to take we're actually going to take many more than 30 so you just move the dial to change that um and start after i might raise that up a little bit too um but basically this is a very simpler intervalometer um and i like how they've laid out the language here it just says take a pic every whatever and so if we're doing 30 second exposures and i want to leave a little bit of time in between the exposures for either the mirror to settle or for the mirror to lock up i would set this a little bit higher than the number of seconds that our exposure is so a couple seconds higher than whatever you have your exposure setting at or your shutter speed um so our shutter speed or exposure time is set to 30 seconds so i'm going to say take a pic every 32 seconds um then these are about how to start this sequence and when to start it um so this is going to start after we leave the magical entered menu after 13 seconds it'll start the sequence and then it'll stop after we've taken 67 shots in this case i'll probably raise that up tonight to many hundred um because the big dipper is is high in the sky and will be up most of the night so we can we can get off hundreds of shots um over the course of the night okay um i mean turn that intervalometer back off until we're ready to use it i will also note it note here uh and again this only applies to magic lantern that uh magic lantern gives you more uh power over how the mirror lock up works um so i can turn the mirror lock up to be always on and i can set actually a delay for how for when to take the exposure after the mirror locks up so the default here is one second so if i set my interval time to 32 seconds that gives us one second for the mirror to lock up and have that delay before it takes the exposure so that should be enough but if you were concerned about mirror shake you could you could do something higher so you could do like a three second delay and then set your interval time to something like 35 seconds um so this um this level of control in magic lantern can be really nice we'll look at this again when we get out onto the field a little bit um oh i should also mention sorry one more thing about this if you are setting your um camera to bulb mode you can then set the bulb timer right here and this will allow you to go um longer than 30 seconds um so you can do like five minute exposures right in camera and again this is a this is something that's only uh often available on external intervalometers normally but magic lantern adds this right into the canon menu system but i'm going to turn that off because we're just going to be doing 30 second exposures but if you do have a dark side or something like that and you and you want to use longer exposures you have a premium mount or something like that then you can you can set off that bulb timer there's just a couple less things to do before we get on the field one is to remember to charge up your batteries including the dslr battery um so just remember hours before you're ready to go out to charge and if you have extra batteries charge all your extra batteries um just in case i like to have multiple copies of everything you never know when you might run out of juice um if your tracker runs off an internal battery make sure to charge your tracker if it runs off double a's like mine then just bring extra double a batteries the worst thing is to get out there and realize all your batteries are dead and you need to charge them to keep going last thing is we need to prepare how to actually find our deep sky object in this case we're going to be shooting m101 the pinwheel galaxy which is actually a pretty easy target to locate with some basic star hopping the basic idea here is we're not going to be able to see m101 with our naked eye or with the camera because of the amount of light pollution we're going to be dealing with but we will be able to see the stars of the big dipper um the big dipper is a bright asterism it's not actually a constellation it's in the northern hemisphere it's part of the ursa major constellation in america we call it the big dipper i've heard in other parts of the world they might call it the plow but in any case um the big dipper is very easy to spot it's very distinctive m101 the pinwheel happens to form a triangle with the the last two stars in the big dippers handle so all we have to do is we make sure our camera is on the right side of these two stars and then we center it on an imaginary spot that makes up the third point of that equilateral triangle with these two stars this case was pretty easy more advanced star hopping involves you know going multiple jumps from a really bright star to a less bright star until we find our object eventually i'm going to do a video about star hopping someday but for m101 like i said shouldn't be too hard just find the handle of the big dipper or the plow and make that triangle with the last two stars in the handle you found m101 okay let's get out to the field well now on the outside uh all the forecast said clear but of course it's cloudy uh happens to me a lot nothing you can do about it but we'll see if uh after i get everything set up here if the clouds clear and we can actually shoot a galaxy tonight um so i've set up my tripod here um this is the official tripod spreader that comes with the optron mount it's a little plastic doohickey here but i don't really like very much because i always feel like i'm going to break it when i put it in there um but that does an okay job at making the tripod a little bit more rigid but i i uh built this this wooden tripod spreader that i like a little bit better um just makes it a little beefier a little bit more stable all right uh so i have it on here now um i do have the tripod raised up a little bit uh just for demonstration typically all for imaging i'll have my tripod in the lowest possible position there is really no wind tonight so um it's probably okay to have a little bit raised up but if you feel any wind you really want your tripod as low as possible the other thing i'm doing here is uh when i line up the tripod i want this little registration pin i don't know if you can see that this little pin right here that's what uh you're going to adjust your azimuth corrections against and basically two little screws push against that and so you want that is lined up with the north celestial pole as best as you can and the easiest way to do that of course is if you're in the northern hemisphere just look up at the sky find Polaris which is at the end of the little dipper and just try to point this registration pin right at Polaris if you're a little bit off that's okay but uh but you want to try to get that as close as possible it'll sort of save you some time later on when we get to the polar alignment step okay next thing we're going to do here is we're going to put the mount head on the top here and then there's a little locking mechanism below that i'm going to screw in all right the latitude adjustment on this mount needs this screw so we're going to put that in right here okay and there's a little latitude gauge right here so i just did it roughly 45 degrees but we'll we'll fine tune that in a second here and you can see that when i transport them out i i have these axes uh loose uh but then once we get it set up here we can go ahead and and lock those down like so and this is uh let me tilt up here a little bit this is called the home position uh basically with the counterweight shaft pointed towards the the Polaris the north the north star or if you're in the southern hemisphere the the southern celestial pole once we have the mount secure on here and we've locked it down we can put the counterweights on the counterweight shaft okay i'm just going to put one counterweight on there to the start and um sort of in the middle because i don't remember uh how heavy this payload is going to be so we'll put the payload on the top here and then we'll adjust the counterweight up and down to balance it in a second um i always suggest putting your your counterweights on first before you put on your telescope um i just feel that's a bit safer uh to have the counterweight already there if you put the telescope on first then if the if it's really out of balance you might have a crash and and break your telescope so i think it's always better to put the counterweight on before the telescope okay now i have everything attached uh including my laser pointer finder uh my little simple dew heater controller and dew heater band and uh the hand controller i just put some uh 3m dual lock fasteners that sort of like waterproof velcro on the back of this and on the front of the mount as an easy place to put it the next step in setup is we want to balance the mount um this mount is a little bit tricky to balance in declination just because it's a little bit sticky here but it should be easy enough to balance this way okay so what i'm doing here is i'm seeing uh which side is heavy and so i can see right now the counterweight side is heavy because when i let go it's swinging to that side so what i'm gonna do is i'm just going to push the counterweight up here on the counterweight shaft until it balances all right so now it balances in both directions i'm gonna go ahead and uh line this back up and lock down that axis okay the next step is we're going to take off this cap here and take off the cap in the front and polar align and this is something that's hard to show with the light on because i can't uh see the uh through the polar scope with that bright light on um at some point i want to do like a full video on polar alignment that will be more helpful but basically what i'm going to do is i'm going to look into that polar scope and line up uh polaris in a circle uh where it's supposed to go and the way that i usually figure out where polaris is supposed to go is i just bring up an app and uh the app tells me well for an iopter on mount this is what the circle looks like this is where polaris should be for your location and time right now so i look at that app and then i look in the polar scope and do my rough polar alignment a lot of times i'll follow up with a more precise polar alignment with something called the qh y pole master which i plan to do tonight um but it's not necessary when you're starting out when you're starting out uh just using the polar scope is is just fine but you want to try to get as accurate as possible which is why i recommend using a smartphone app for this okay um i'm going to turn off the light and do the polar alignment okay if you happen to use a qh y pole master you can watch this section if not uh you can just skip over it i'm going to show uh how to do a fine polar alignment now with the pole master so i've put the pole master adapter into the bore hole right there on the mount and then we just snap in the pole master like that and tighten these locking screws on the side and for uh the best uh experience with the software you want the usb pointed this way so if you're facing your mount it should be pointed to the left uh it doesn't matter too much but it it makes the directions uh when you're adjusting things make more sense on screen okay and then i'm just going to put in the supplied usb cable there and that has locking screws too okay and that's uh all installed so now we'll move over to the computer uh to finish up because uh the pole master is mostly just you just put it on um with the the axis of the mount um you know where uh where you normally polar align from and then you just moved the software side to actually understand the polar alignment um once we're in the software we're just going to be controlling uh we're just going to be adjusting it to get a finer polar alignment with two two different sets of knobs um the azimuth adjustments are down here and those just work against a registration pin that's right there and then the altitude adjustment is uh this thing right here for sort of fine control and if we need some major adjustment we could we could loosen up this uh this bolt back here um and okay so we'll move to the software now i'm going to go ahead and make this full screen and then i'm just going to use these scroll bars to roughly center polaris which is the only sort of brighter star on screen i'll go ahead and raise up the exposure time a little bit the goal here is to make these stars around it bright enough to clearly see so if i raise it up to 200 milliseconds now i can see all of those you can also play around with um the gain too if you want but um in this case it's just making it noisier and i'm not actually seeing any more stars so i'll leave that alone and click finished i'll double click polaris again and uh use this little rotate slider thing here and i find that when you're just using this rotate slider by hand to try to match up the stars it's very easy just to shoot past it when you're close so then the easiest thing to do is either you can use these buttons the minus and plus to make small adjustments or you can use the left and right arrow keys which is my preference and so i'm just going to use the left and right arrow keys until i have this all matched up i can just double check by moving this up and down yep and i'll say success and it says would you like to use the axis center position recorded last time you used pole master i'm going to say no because i was using a different mount the last time i was using the pole master software so we have to rerecord this it now knows that this star is polaris so i can pick any star out here to to use for this step i'm going to pick this one way out here and i'm going to double click it as the instructions say then it says to rotate the array axis in the direction of the arrow so we're going to loosen up the array clutch here and move that star up here double click it or no say finished then double click it again and then do that same thing again it's now up here finished double click okay and then we're just going to loosen up the clutch one more time and watch that star as it moves back to where it was and make sure that it's roughly staying on that green circle we're a little bit off just because this is a cheap mount but that's okay it's pretty close to that staying on that green circle i'll say correct i'll double click polaris again use my left arrow key to put these stars back into the pattern and click success okay and now this shows us how far i was off with just my rough polar alignment using the polar alignment scope built into the iop crown smarty q so we have to now move polaris from here to this cross hairs in the rotating circle right here and it's mostly going to be an azimuth move because we're pretty close to the right altitude so i'm going to start with those azimuth adjustment knobs and this is a live view so as i'm moving these knobs you can see it moving on screen now we're pretty much lined up in azimuth so now i just have to raise the mount up a little bit in altitude okay now we're getting quite close we're just going to use the azimuth adjusters again and you have to sort of work them both at the same time you loosen one while you're tightening the other to make it move okay that looks right on i'm going to click finished says double click it again and use the rotate slider or just the arrow keys say success and now we click the start monitor button and what we're looking for here is that that green target stays basically centered within that red circle the red circle is where our mount is pointed and the green target is the celestial pole and it's monitoring this in real time the reason it's jumping around a little bit is because of the seeing the atmospheric turbulence in the air and let's just try to fine tune this a little bit it's going to be difficult on oh maybe that did it no it's a little better jumping around a bit so it's hard to say i think that's close enough for our purposes okay so i'm going to say finished again and close out of this application the next thing i like to do to try to get a little bit better with the first go-to command the accuracy of that when we're doing the three star alignment is to make sure that the the mount is truly in the home position now that we have it polar aligned and what i mean by that is that Polaris which right now is right there on the screen should be roughly centered so i'm just going to loosen up the declination axis here and just nudge that back and forth that's pretty good until Polaris is centered as much as it can be this way and i just find that that helps get you closer with your first go-to command or your first alignment if you're doing like a three star star alignment to refine the go-to and the other thing we can do at this point you're probably not going to be able to see it very well hold on let me turn on my headlamp here is remember i'm using this laser finder scope and so i'm going to just adjust this at this point to make sure that it's pointed at Polaris too the way i'm going to do that is just look for airplanes make sure that i'm not that i'm safe to shine the laser and then if i don't see any airplanes coming i'm going to just press down right there to shine the laser look up at where it's pointed in the sky i can see the green laser beam and then adjust it with these knobs until it's pointed at Polaris so then i know the camera and the laser finder are now aligned which is important if you're not using a laser finder but a tellrad or a red dot finder you would do this same thing to make sure that the two things are aligned meaning they're both pointed and centered on the same star you need to do this before you can trust what you're seeing with the finder so that's all done now we can move on to turning on the mount and doing a couple star alignment before we move on to m101 okay i'm now turned on the mount and i have the hand controller right here i'm going to start by setting the time and site and that's actually looking pretty good it remembered most of everything that's the right time the next thing after setting the time and site information which you can find like on your smartphone app i'm just using polar finder pro here to find my gps location and the current time and date the next step is we're going to go to alignment and i'm going to do a two star alignment meaning we're going to use two stars we know in the sky to align the go to application to align the mount so that it can um then get more accurate at its go to the ability to go to any object okay and then this is an alphabetical list we're just going to hit down or no it's not an alphabetical list it's a list of writer stars that are good to align to so we're just going to hit down till we find one that we like okay and i found one uh dubi um is in uh the big dipper so that's where we're sort of headed that's where i want to go so i'm going to use that as my first alignment star i'll just hit enter here and the mount starts slewing okay it then says use the arrow keys to center the target and then press enter so that's what we're going to do we're going to use our laser finder and possibly live view to get it even more centered um and then use these arrow keys to center it using the laser and live view i'm not going to show this because it's just sort of cumbersome right now because the camera's pointed straight down but you can just believe me that we are doing this and uh it's really pretty easy especially uh if you do have a laser finder like we do here and now i found another star fekta that we can also align to in the big dipper the reason i'm staying in the big dipper is because m101 is very close to there if you align on a few stars close to your object that's going to work a lot better um for fine tuning the alignment here okay so we'll do this again and uh i should note that when you're done um aligning so first i'm going to slew it's slewed and now it says use the arrow keys to center and then press enter so after i'm done aligning with the arrow keys um we press enter uh one other thing i should mention here is if it's going too slow you can change the rate of the of the slewing around um with these buttons so nine as the max one would be slowest and so i usually start on your five or six and if it's really off you can go up to nine um but usually around four five or six uh works pretty well for me on this okay now i'm going to do uh focusing with this botanava mask we just um put it on the front of the scope like this um and then take some exposures and uh we try to line up that center spike between in the x pattern um this scope has a very nice two speed focuser which i'll show right now okay so we're going to rack the focus in one direction just a little bit about a quarter turn that looks good just to test that i'm going to go ahead and take a six second exposure with the bad enough mask on see that so that's good focus with the bad enough mask that central spike is uh right in between the other two and i'll go ahead and take it off now okay we've done our uh two star alignment we've focused on a bright star and now we can go ahead and move to m one oh one so i've just chose the select and slew i'm going to go down to messy a catalog and type in m one oh one enter slews to it and uh now we'll take some test exposures and see how close we are maybe we'll have to do a little re-centering but uh should work okay so i've hit the trash button which uh because i put magic lantern firmware on this camera has been keyed to open up magic lantern it gives me this little uh information about uh the versioning and telling me that this is a nightly build i'm just going to press the set key to enter the menus here's the different um magic lantern menu system um there's a lot of different things in here and i'm not going to go over much of it because we're just going to be using it for the intervalometer function uh which is under the shoot menu so that's five over from the left in this little camera icon i'm going to go down and if i just press the set key that just turns it off and on if i press the q uh button then that's where i can set up the settings here um so i'm going to change this to 32 seconds meaning that um we're going to do 30 second exposures there'll be a two second uh interval between them and then it'll just take another 30 second picture um i'm going to have the start trigger be leaving the magic lantern menu you can also set it to a half shutter press or just to start after you take the first picture leaving menu is fine this start after means after we leave the menu how long do we want it to wait before it starts the sequence of exposures 12 seconds seems fine if you feel like you need a little bit longer to get out of the vicinity of the mount so you're not stomping around it go ahead and set that higher and then this last one stop after if you're just planning to do you your darks or uh flats first because uh you want to get those out of the way before you take your lights you could just do 30 we're going to jump right into our lights here um and so i'm going to set this to 400 okay and this last one ramping options that's if you were that's a more advanced option if you were doing a time lapse but since we're not doing a time lapse we don't need to turn that on i'll press q again to exit the intervalometer is still off to turn it on i just press the set key it now says on and then i can just leave the menu by pressing the trash button and it will start the sequence after 12 seconds okay before we jump into pre-processing let's take a look at one each of a bias dark flat and light just to give you an idea of what they look like in their raw state before we do any calibration or stacking so i'm just going to uh double click these to open them up in adobe camera raw um at first glance the bias and the dark look exactly the same they both just look completely black but if we stretch them a little bit by just moving the exposure slider all the way over to the right plus five stops we can see they look a little bit different they both have vertical and horizontal uh banding but the bias frame looks fairly clean in terms of hot pixels while the dark frame has a number of very bright hot pixels which show up as these bright red green or blue um hot pixels in the frame and the reason that some appear bigger than just a single pixel is because of the way that the bayer matrix works they'll expand uh beyond just the pixel that they appeared on originally so that's hot pixels uh basically the bias frame is just the fixed pattern noise on the sensor so you can see there's some random sort of salt and pepper like stuff there um and also but what's more important than the random salt and pepper stuff is these lines that we see because those should be fixed on the sensor and we can remove those kinds of fixed lines in the calibration process just like we can remove hot pixels with the darks okay and then here is the flat um i'm just going to actually bring the exposure on this one down a little bit just to show you uh hold on let me try increasing the contrast there we go bring up the whites a little bit just to show you there's there's a little bit of vignetting in the corners um and if we zoom in there's an example of some kind of dust moat you can see it's a little bit of a circular little pattern that's an out of focus piece of dust or something like that there's a couple of them here um so yeah so that's a flat and then finally our 130 second light looks like this uh m101 should be right here in the middle if i zoom in you can barely make it out there uh let me try playing around with these sliders a little bit to see if i can help it all and you can see when i when i stretch just a single 30 second image the it's so noisy especially without calibration that it doesn't do much help uh but believe me there are spiral arms of a galaxy right there once we get through the whole pre-processing stage and can subtract the light pollution you will see that galaxy is right there uh that's m101 um i've been doing this a lot enough that i can sort of recognize okay yeah there's like a fuzzy little thing right there that's clearly the galaxy actually it stands out a little bit better i think when you when you zoom out so that's about what you get in a single light exposure meaning the single shot of the night 30 seconds but again we're going to stack hundreds of these so our final exposure will be sort of a combination of about a few hours of data okay so hopefully that sort of showed you what the different frames look like the light and then the three calibration frames the flat the dark and the bias now we're going to take all of these and move on to pre-processing i've switched over to my windows laptop now and the reason is is because deep sky stacker is a windows only program um if you are interested in free stacking on a mac or linux machine i am gonna make a video about seral as well which also does this same kind of stacking process but i do like deep sky stacker if you do have a windows computer because of how simple it is and it generally gives you also very good results so the first thing that i'm going to do in deep sky stacker you may not have to do it depends on how much internal storage your computer has i know that i'm running a little bit low on local storage or internal storage so i'm going to go down here to the settings option under options and click on stacking settings then under stacking parameters this little window that opens up right here i'm going to go on to the tab all the way over to the right called output and i've already said it here previously but um normally this would say something like c drive and it would put it in a temporary folder on your c drive which is your local storage drive your internal hard drive um i'm working on a laptop with a small ssd and i know that this temporary folder often uh grows to gigabytes and gigabytes while you're working in deep sky stacker after you close out the program it does delete it but while you're working you need a very big temp folder so what i've done here is i've clicked on this little um button with the three dots and i've told it to instead use a temp folder that i just created on my external hard drive which here is called 2019 backup and it's the d drive on the computer and so whoops i just accidentally set it to the d drive i want to set it to temp folder on the d drive just to keep things a little bit more organized there we go and once i've done that i can go ahead and click okay and it will remember that setting it will even remember that setting the next time you open deep sky stacker if you were wondering um assuming you have that external hard drive connected okay next we're going to now we're going to actually get onto the main show which is starting at the top here over on the left and just working down this list of things to do i'm starting with open picture files and the first thing that i'm going to do is i'm going to navigate to my folder m101 folder that's on my external hard drive and i've already organized the files into these four folders using um adobe bridge but you can also just use uh your file system to do this because as you can see when i open one of those folders it does give me a preview so i can see that all of these are lights if you have to see them even bigger you can change it to extra large icons and i can see that there are stars in there um okay uh but anyways what we're doing now is we're opening up all of our lights so instead of just clicking on one and clicking open i want to first select them all so i'm going to click on one and then i'm going to press ctrl a to select all of my lights and then click open just to show you that it worked i can scroll through here and you can see they're all highlighted meaning they're all selected and if i click open you can see that it brings these all into a list right here like that now for some reason deep sky stacker when you bring in this first batch of lights it doesn't select them all the reason it does this i think is because what deep sky stacker expects you to do is to go through your lights one by one perhaps and check the ones that you want to use if you've already checked your light frames in a different program like i did in adobe bridge you don't have to do this process and you could just go over here on the left hand side and click check all to check all your light frames so you can see i now have 392 checked i did leave in a bad light frame here just to show you what the process might be like if you were manually checking these in deep sky stacker so this second one i know is a fairly good light frame and if i just move my mouse over a star sorry it's a little bit tricky with the trackpad okay there we go so if you look over here in the left hand side this is a 100% zoomed in view and you can see the star is a little bit ovular a little bit egg shaped that's okay i don't expect this to be perfect but that's that's a fairly round star right and if i look at a few more stars try to find a big one here yeah that one is nice and round so that looks like a good frame and if i just click on another random frame here and look at that same big star again it's a little bit off but fairly round that one looks pretty round right okay so all of these frames are looking pretty good so far but now let me show you a bad frame to show you what that would look like and it's this first one here i left it in purposefully if i move my mouse over this you can see that star looks quite weird it looks sort of doubled up and then if i look at another one the same thing if i look at yet another one same thing another one same thing they all have this left to right double pattern um and the reason this happens is um well there's lots of reasons it can happen the reason i think it happened not here is because i was probably still walking around the mount um when i was leaving after i'd set it up to take a bunch of exposures and because the ground was wet the mount shake shook a little bit and that gave me these double stars so i don't want to use this frame in my final result because it might just leave um a little trace of that double star so what i want to do is i want to remove it from the list the easiest way to do this is just to right click on it and choose remove from list and you can see our total number of light frames went down from 392 down to 391 and so you could do this just moving through for each frame and examine them all um if you have another program that you prefer you can do it in there and then just bring all bring in the ones that you know are good um oh i'll also mention really quickly here that it does also have this thing up here which lets you brighten up the picture just like that it's marginally useful when you have this much light pollution uh because we still can't really see any kind of deep sky object but i just let you know that that's a that's a temporary stretch of your image so it doesn't do anything to the final image it's just for you to view um right here okay uh that's enough about lights i'm going to leave all of those checked and then we're going to go over here back to the left hand side and open up our dark files and we'll go into our m101 folder click on the first dark press control a to select them all open them up um dark frames it doesn't deep sky stacker doesn't think that any of those are going to be bad or that there's any real reason to examine them so it immediately checks them all so you can see as soon as i brought those in it brought in all 30 same thing with the other calibration frames so i'll bring in my flats here and i didn't do dark flats because these flat frames if we scroll down to the flats and then scroll over you can see that um there's a lot of cool information here actually um these flat frames are only one 25th of a second and because they're only one 25th of a second that's not much time for dark current to build up also called thermal noise and so they're usually the only reason to do dark flat frames is if you're having a problem with bias calibration or if your flats are particularly long like 10 or 20 seconds and you're worried about thermal noise in them but with such short exposures i'm not too worried about uh thermal noise and so i'm going to not use dark flats but we are going to use bias so i'm going to click on the bias files here make sure i'm in my biases folder and click on the first one press control a to select all and click open and i shot 50 bias frames mostly just because they are so short to take um if you are at all unsure about which are your bias frames and which are your dark frames another thing you could do is you could just open up all of your pictures and then uh sort of go through here and find okay well here's all my bias frames they're one eight thousands of a second there's my flat frames they're one 25th of a second and there's my dark frames because they're 30 seconds to match my lights so you can use deep sky stacker to figure out which files are which and then just reload them in as darks flats and bias if you were if you hadn't already organized them as such just wanted to show you that exposure column just in case it's useful uh the other uh the other thing i can check here is that everything is the same iso if i scroll up to bottom bottom to top yep everything is iso 800 which is good all right uh at this point if i were doing this live with people i'd probably ask if there are any questions but uh if i've missed anything i always just ask me in the comments because i uh you know i'm doing this live but i it's it's hard without an audience um okay so we have everything loaded up here everything is checked i know that because um it has these numbers right here so for instance if i clicked uncheck all you can see they all reset to zero if i click check all then we have them all except for the dark flats which we didn't take so that's what you want to see before we move on to the next step which is we want to click on this register checked pictures okay and basically in deep sky stacker i use the defaults for the most part um i find that the defaults work pretty well for most kinds of pictures and really the only reason to move off of the recommended settings is if you are a more advanced user who knows uh a bit more about astrophotography and aren't getting the results you want um i'll just show you a couple things here though if you some of these things might be if you run into problems um so the first thing is if you are running into problems a lot of times it's because you you're having trouble with registering your pictures together and um a lot of that comes down to this star detection threshold what this basically means i think it starts usually at 15% or so is it's the detection threshold is how big a star it's going to look at before it counts it as a star so if we move this to the left and we lower the threshold then it's going to let in smaller stars but at a certain point it might be confusing a star with a hot pixel or other random noise in your picture and so if we click that you can see at 7% it's can it's uh finding 405 stars if we bring it up to 65% now it's only finding 32 stars so what is the right number of stars to avoid it lashing on to noise um it's hard to say exactly it really just depends on so many factors but what i usually do is i try to look for a threshold where it's finding a few hundred stars a couple hundred maybe between 200 and 300 stars of course this really depends a lot on focal length so if you are doing milky way shots or something like that it might find thousands of stars and that could be perfectly normal so uh don't let the exact number of stars be your guide um really it's just you might need to change this threshold if you're having problems with registration usually there's no reason to change it off of the default unless you're running into issues okay next thing here is where it says stack after registering i think that starts off um unchecked but i usually just go ahead and check it um that means that we're just going to get through everything right now the other option is if you uncheck it you could just register your pictures then uh deep sky stacker applies a score to every picture and then you could use the best uh picture to do uh to re-register and and and stack and everything i just don't find it particularly necessary with this kind of thing so i'm going to go ahead and click stack after registering um and where it says select the best percentage of pictures you can set this to whatever you want so if you're not sure about you know the quality of your pictures you might want to set it lower um i'm fairly sure that these are fairly consistent so i'm going to set it higher i'm going to set it to 95 percent meaning that the worst five percent in terms of the stars being out of round it's going to throw out before it stacks them all together um next thing we can do here is there's two buttons down here there's recommended settings and basically all you want to do here is make sure that it's not throwing any big errors at you if there if it was throwing any big errors it would they would show up in red um and then there's stacking parameters and this is where it gets a lot more advanced but the good thing is again the defaults in deep sky stack are quite good so there's really no reason to change any of these unless you really want to um basically what just a straight i'll just explain quickly what a stacking mode is a straight average would mean that it doesn't do any waiting it just it it just looks at every picture is equal and and stacks them all together a kappa sigma clipping is it it does a distribution and it looks at things that are outliers and it would throw outliers out and you really want this on especially if you're imaging from a city because you're going to get a lot of satellite trails a lot of plane trails different things in your pictures if you just do a straight average those will those will show up in the final stack faintly if you do kappa sigma clipping those will disappear because it will throw out those pixel values and outliers um okay hope that makes sense for result we just want the standard mode that's what you want when you're stacking a bunch of pictures together into one master uh exposure mosaic and intersection mode are if you're are trying to make a mosaic of the sky so basically you're you're moving your camera all over the sky and trying to make one uh bigger field of view that's not what we're doing so we're going to leave it on standard mode um you can only these drizzle options are very interesting and they uh do seem uh and you know like we would want this because the galaxy is going to be very small on our sensor but unfortunately because we didn't have a mount that uh we didn't do auto guiding with dithering uh we can't use drizzle um that really only applies if you are dithering meaning moving the the field a little bit between every frame otherwise drizzle doesn't work okay uh i'll click okay everything is fine here so i'm going to click okay again it gives me a final uh check here this is just a screen that explains everything it does uh explain down here that this process will temporarily use 53.9 gigabytes of on the d drive so that's what i was concerned about with with having that temp folder on the c drive because i'm not sure if i even have 53 gigabytes available um and if if you don't have that amount available then the process will fail um it tells me that my total exposure in terms of lights is three hours 15 minutes so it with 391 uh light frames at 30 seconds each that's our total exposure time and that's it uh we can go ahead and click okay it now starts off the process and um i will mention here that right now you can see the first thing it does is it says adding offset frame what that means in deep sky stacker speak is uh it's putting all of the bias frames together into a master bias um and i'll mention here that right down here it says estimated time remaining time one minute 52 seconds that is not the total remaining time that is just the total remaining time in this step which is just the first step in many steps it has to do um to make our final picture um because it has to first add together all of the calibration frames to make master calibration frames that uses those master calibration frames to calibrate the lights it then registers all of the lights and then finally it stacks all the lights and some of these steps will take a lot longer than others but i expect this whole process to take hours uh considering we're stacking 391 lights so i'm just going to leave this what i would suggest is make sure you're plugged into ac power and just leave it overnight or if you're going to work you know leave it going during the work day and then you can pick it up in the evening um i'm going to stop the video here and pick it back up when this is all done okay it's now finished stacking and we do get a little preview here and there is the ability to alter that preview and even save these changes that you make in deep sky stacker i don't recommend actually using these histogram sliders or these different tabs here because it's pretty coarse and a little bit hard to use these adjustments and you're going to get much better results in gimp or photoshop or any other program that's better for the post processing uh what we can see here though i'm just going to use two fingers on my trackpad there we go um or if you have a mouse with a wheel a scroll wheel you can use that um that we do see the galaxy now so remember in our individual lights we couldn't really see it now we can see the spiral arms right there um but we're going to bring it out a lot more when we do post processing um the one other thing i want to note here before we move on to saving is if we look at this this is um the linear response of the channels and for some reason the blue channel looks almost stretched already i'm not sure why that is um it's not uh it's probably has something to do with my light pollution here um but it's something to um be aware of this is a very linear response when the when the spike is like very up and down like that and this is a more non-linear response when it's uh when it's stretched out like that um so i'm not sure why that happened but it's something that may impact our processing and photoshop so for instance i might immediately stretch the green and the red to more match the blue before doing more stretching um hope that makes sense you will see if it doesn't make sense you'll see in uh the post processing what i'm talking about okay the only thing we have to do now is save it does create an autosave uh that is a 32 bit file since in previous videos i've uploaded the 32 bit file has been causing some issues for people um it's really no big deal let's just i'll show you how to save a 16 bit file that's in this raw state um and it's really easy you just go over here to the processing window you just go over here on the left hand side to where it says processing there's a little blue box and the final option is save picture to file go ahead and click on that and the default option is tiff image 16 bits so that's exactly what we want uh don't choose any other option here unless you you know we're going into some other uh advanced astro imaging program then you might choose one of these like fits options um or if you know that you can work with 13 bits and you and you want to start in 13 bits and 32 bits okay the default option here is tiff image 16 bits per channel which is exactly what we want it also should be the default option that down here it says embed adjustments in the saved image but do not apply them and you want to leave that checked um we don't want this apply adjustments to the saved image because then anything that we did down here for preview purposes would actually get um applied to the image permanently and you can't reverse it um what we want to do is just get this image in its raw state um and bring that into our next program for compression i'm just going to leave it on none i'm going to go ahead and call this uh m 101 dash d s s and i'll save it to the desktop that's fine okay it's done saving and just to check here i can double click it and when it pulls up in the default photos viewer it should look mostly black that is what we want to see um if you see a very bright image here something may have gone wrong with your processing i've now moved over to my mac and opened up adobe photoshop cs6 if you have a different version of photoshop no problem everything that i'm going to show should uh be relevant to any modern version of photoshop if you uh if your photoshop looks very different than mine you might just want to change it to the essentials workspace um and uh that should work just fine the thing the things that we're mostly going to be using are uh the menus up here a few of the tools over here the layers and the adjustments um okay so the first thing we're going to do is go up to the file menu and choose open and i'm going to open up that uh m 101 dash d s s tiff that's the final result from deep sky stacker that we saved as a 16 bit tiff file i'll click open it opens like that fairly dark first thing i'm going to do is i'm just going to double check that it's in the right mode so i'm going to go up to the image menu and choose mode and just this looks right rgb color and 16 bits per channel the next thing i'm going to do is i'm going to duplicate this layer um so we can do that by uh going to layer duplicate layer or you can use the shortcut command j if you're on a mac or control j on windows and i'll just call this duplicated layer first stretch and then as the name of this new layer suggests what we're going to do is we're going to stretch the image and that means um make it brighter of course but also um go from a fairly linear response and and stretch it out to a non-linear response and normally if you just uh shoot in raw and then open a file in adobe camera raw it applies this curve automatically that that does this for you but we're doing it more manually and while we're doing this it can be helpful to have the histogram display open uh if you don't have the histogram button um what you can do is just go to window and make sure that it is checked right here and then it should be available over here on the right hand side of the screen and if yours doesn't look like mine this is the fully expanded view just click on this little hamburger menu in the upper right and make sure that you are now it's not the expanded view sorry it's the all channels view that's the one i find most helpful um because it shows up here the blue green and red channels in one plot and then down here it shows them in separate plots and that's very helpful because i can see that the red is is out here the green is here in the blues here and just like we saw in deep sky stacker for some reason the red and green channels look fairly linear we have this very up and down uh all the information is compacted into this one little spike um for some reason the blue channel is a lot more spread out and uh also farther over to the left almost clipped um so we're gonna have to do some work here when we stretch and we're we want to be looking at these histograms as we're doing it okay now we're ready to move on to the stretching so make sure that you have first stretch selected over here in the layers panel on the right go up to the image menu and down to adjustments and then levels and we're going to keep coming back to levels over and over again so i would recommend looking at what the keyboard shortcut is here and using that so i'm on a mac so it's going to be command l for levels if you're on a windows it will probably be control l uh i'll pull that up you can see it gives us this uh version of this histogram but just in black and white so now we know that this is blue green and red the three spikes and the first thing that i'm going to do is i'm going to try to level those out a little bit so instead of them being so separated i'm going to try to uh fix the the the separation um and align them a little bit um and the way we're going to do that is open up this channel's uh drop down right here in the levels command and start with red and i'm going to stretch out the red channel a little bit just like that so what i've done here is i've moved this middle slider over and the left slider over so the left slider indicates the shadow area and so we can see we were well off the the zero point here so i can i can get away with moving that a little bit to the right and then the mid-tone slider this is the main way we're stretching we're moving that into the left and you can see what that does is it pushes the whole red uh peak over a little bit but it's also stretching it out um i'm going to do the same thing with the green and i'm just going to try to with this mid-tone slider line them up like that okay and i'm going to keep doing that stretching these out a little bit i'm going to ignore the blue for now so i'm going to go back into the levels command command l for mac or control l on windows and i'm going to do the same thing again i'm going to stretch out the red just by moving these two little arrows in on the peak and same thing with the green and i mean i have to be a little bit more aggressive with the green it seems to get it lined up like that um i'm mostly at this point just looking at up here into the histogram window but it can also be interesting as you're doing this to zoom in and look at the galaxy a little bit and you can see that it is spiral arms are coming out a little bit don't worry too much about all this green noise right now um while you're stretching okay um so now the red one is looking a little bit fatter than the green one um so maybe i'll try to fix that a little bit just by moving that looks a little too fat uh sorry still a little too fat something like that yeah i'm gonna have to do it again okay sorry this can be time consuming again you just press command l on mac or control l on windows to bring up that levels command again and again okay now the these are fairly uniform um now let's bring the blue channel up so i'll move to blue push it over wow it's quite fat uh so let's see what we can do here now you don't uh you don't want to clip this blue channel too much we're just trying to bring it out from that uh left edge okay so i can see that i now have it out of the left edge because i have a little bit of separation over there and the issue now is this blue channel is so fat that we're gonna have to stretch out our red and green some more to get them equal with that blue channel okay so i've stretched out the red quite a bit just now but then i'm gonna have to move it back over to the left something like that okay now i'm gonna have to work on the green channel okay so at this point i'm gonna zoom out a bit and we have some very nasty gradients going on here and that is influencing what we're seeing up here in the histogram display so this bright green thing up here is a lot coming from the stuff over here um and so and then the blue of course uh this part here is from the background uh there at this point though we don't want to let the image itself be too much of a guide for how we should alter these at this point all i'm really trying to do is stretch them out get them fairly lined up and off that left hand side um so i'm just gonna do one more thing here with the blue channel i'm gonna try to just lift it up a little bit just to get a little bit more separation there okay and then um at this point since i can clearly see here's the galaxy with its spiral arms um i'm going to crop at this point um so i'm gonna open up the crop tool and roughly center the galaxy and get rid of some of this stuff along the edge mostly go for a blue background here but it's okay to include a little bit of that nasty gradient on the left side okay and by cropping you can see our histogram things uh moved again um now the blue is out here and the red looks a little bit anemic um let's just stretch the red just a tiny bit here just to get it starting at about the same spot as the green and the blue okay that changed the gradient a little bit uh of course it also made that peak quite a bit fatter it's now matching the blue pretty well but now the green is looking a little bit too narrow so one more thing here with the green let's go ahead and stretch that one out too okay um now let's get rid of this funky rainbow sky background that we've developed through a light pollution subtraction step and the way we're going to do this is we're going to first select all so this will just select the entire image we're working with you can go up to the select menu and choose the first option all or press command a on mac control a on windows to select all then we're going to copy this is under the edit menu so edit copy command c on mac control c on windows then i'm going to press uh go to file new to make a new document and it uses the pixel information the size um and uh bit depth that we just um copied to the clipboard so we don't have to change anything here because if you first copy and then do file new it will remember all those settings i'm just going to call this bg for background and say okay and then i'll paste it in with edit paste or command v control v on windows i'll go ahead and delete the background layer we don't need it and the what i'm going to do here is i'm basically going to smooth this out so that all we have left is this colored background and none of the detail of the stars and the galaxy and i'm going to do you use a filter for this so if you go up to the filter menu and go down to noise and choose dust and scratches okay at uh anywhere from about 100 pixel radius to 158 we get fairly the same amount of uh blurring but there is still a little bit of strangeness around the galaxy there so where it's a little bit you can still see that it's a little bit brighter but we can fix that after the fact so i'm going to go ahead and apply this at about 128 and then what i'm going to do is i'm going to um use the clone stamp tool here to just um fix that up a little bit uh so i'm going to turn down the opacity of the clone stamp a bit i'm going to do 58 percent i'm going to uh hold down option or it'd be alt on windows to sample up here and then bring that down and just click a few times to even out that gradient right there so it was a little bit too bright on the galaxy and i just evened it out a little bit um so now we have a smoother uh finish here speaking of smoothness uh if if your gradient doesn't look very smooth another thing you can do is blur it out a little bit with uh gaussian blur something like just some you know a huge pixel radius is fine here we want to make this basically this model um as smooth as possible uh for a proper subtraction okay so now if i look at the background model we've created then i look back here it's looking quite good we've taken out all the stars in galaxy there's no obvious hot spots um if you're wondering about this feature right here um that is a dust mode that somehow didn't get subtracted by the flats that then because of drift in the image uh turned into a line we're going to deal with that towards the end of the process so don't worry about that yet um okay next thing we have to do is we have to save this background layer this is very important it's very easy to forget you want to save this as a photoshop file so just go to file save as and save it as bg.psd for background okay now go back to your m101 image and i'm going to duplicate again i'm going to just press command j or control j on windows you can also get to it by layer duplicate layer and i'm going to call this bg-removal and the way that we're going to remove the background here is we're going to go up to the image menu and choose apply image from the image menu okay the first thing it tries to do is it tries to subtract the image from itself or actually multiply the image by itself and that's because in the source command it always will pick its itself first but we want to change that to the background that we just created we want to go down here to the blending mode and change it from multiply to subtract okay and then um i've already set the scale to one offset to 60 that's from previous uh you know attempts at this or times i've been working with photoshop on something similar but you may have to play around with these a little bit usually a scale of one works fine if it wasn't set to one go ahead and set it to one i think it can go from one to two um can it go down to zero no it has to be between one and two so let's see what it does at 1.5 you know i don't i don't think you'd ever want it on anything other than one because i think anything if you scale the subtraction i think it's always going to apply too much blur but what we do want to change is the offset um the offset is basically how much uh how many pixel values it's going to add above a baseline when it does the subtraction and so if you set this to zero you can see it's subtracting way too much and clipping you know 90 of the information to black if you set it to 200 then the picture is way too white so you're basically finding a a balance here and usually that balance is somewhere between 30 and 100 um but what i would suggest is at this point make the picture a little bit grayer than you want it to be um so even if you think at this point it looks a lot better set to 20 i would recommend you know at least doubling or even tripling that at this point because this sort of more gray look even though it looks a lot worse this is just an intermediary step and we're going to do a lot more with the picture so what we don't want is set the offset to low and then you you lose detail that is not recoverable so here's what i mean see at offset 15 look at the this outer galaxy arm and now let me bring that up to 60 and you can see that it's i mean there's a lot of noise there let me let me try it down here okay look at this look at these galaxy arms these are you know arms of the spiral galaxy made up of stars and you know there's noise in this image but you can see the galaxy arms up here quite clearly down here they're sort of fading into the black now let me bring the offset up to 60 and you can see them a lot clearer um even though there is a lot of noise in the image still we can see that there is some detail in here that we want to bring out okay so 60 offset looks good to me but again just play around with this until you get a fairly nice uh gray image where all the detail is preserved and you're not losing anything actually let me just go back and forth between 60 and 80 here 70 actually i'm gonna go with 70 uh this is a little bit brighter uh but i think that looks a little bit better um in terms of preserving details that we might want later okay uh so enough said about that let's go ahead and click okay here's what the image looks like now um it's fun once you have stretched your image like this and subtracted the background light pollution background um to see all the little cool details that have come out this you know might look just like a stretched star but i am almost positive that that is actually a background galaxy it's an edge on you can see um there's also a sort of a regular galaxy up here um um and sometimes it can be challenging to know what is uh a defect you know what's a dust mode or something like that and what is actually uh a whole other galaxy this is a fun part of deep sky imaging is that you have to get a little experience to recognize what is defective in your image and what is uh what is actually something cool that you've captured um so because we captured this from a very light polluted area um there's a lot of noise still left in the image we're gonna try to deal with that um a lot of color noise uh but also just random noise and the the galaxy itself uh when you zoom in on it it doesn't have a huge amount of detail but enough detail that when you zoom out i think it looks pretty cool you can at least see the nice spiral pattern okay um so next step let's look at the histogram again okay um after the background removal step um they're fairly lined up which is good but the blue channel is a little bit skinnier than the green and red so let's this might not hold but let's um go ahead duplicate this again and call this second stretch just to see if we can bring out the blue a little bit without messing up the image too much so i'm gonna open up the blue channel i'm gonna open up my histogram view here and i'm just going to stretch it a little bit all right let's try that let's try just a little bit more sorry a lot of times i just find it's easier to iterate rather than try to get it perfect in one go okay i think we're we're we're getting at more natural color here um with these all lined up and fairly uniform now um let's reset the black point a little bit just by opening up levels one more time this time we can leave it on channel rgb rather than looking at the individual channels and i'm just going to bring the levels on like that a little bit um so bringing the shadow slider up so that it's not clipping anything but just um like that the next thing i need to handle um all of the color noise in the background is a luminance mask and we're gonna we're gonna apply that luminance mask to the background only so we can desaturate it and possibly blur it a little bit um and so the way i'm gonna do that is i'm going to duplicate the layer again if you don't know the shortcut by now it's command j or you can always go up to layer duplicate layer and i'll call this uh loom luminance mask um and to make it a luminance mask i'm going to go to image adjustments and apply a black and white adjustment to it like that and so you can see it took out all the color makes the picture look quite a bit better already because most of what we have is color noise um and then i'm going to open up a curves adjustment on this command m control m on windows if you want the shortcut and i'm going to do a fairly aggressive s curve and i'll probably do that a couple times actually curves okay and so basically what i'm trying to do with this is um make a fairly black and white mask so um the background should be fairly uniformly black while the actually that looks better while the galaxy and the um stars are all white so here's the original image and there's our luminance mask okay now i'm going to uh open up a hue slash saturation adjustment layer so to do this if you look here's the layers command over on the right i mean the layers panel sorry over on the right and here's the adjustments panel right above it to open up the hue slash saturation adjustment just click this button right here and it opens it up um and you can see that automatically it has a layer mask um applied to it but that layer mask being all white means that it's going to apply to everything and what we want to do is we want to use our luminance mask to have it only apply to the parts we want it to so what i'm going to do is i'm going to select this with um select all i'm going to copy it edit copy command see and i'm going to uh hold on option on a mac or alt on windows and click on that um mask thumbnail on the hue slash saturation layer and then i'm going to paste it into there and so now you can see that's pasted on i'll click back out um but it's there and i can actually now hide this layer we might need it later so i'm just going to leave it i'm not going to delete it but um i'm just going to turn off its visibility by just clicking the little eyeball right here okay and nothing has happened to our image yet i know that was a lot of steps to get no uh visible progress yes but we're about to make a bunch of dramatic changes using that mask that we just made so let me go ahead and deselect um and right now uh white selects so basically uh if you remember that about mass that white selects if we anything that we do on this hue slash saturation layer is going to apply to the parts of the image that are white and not apply to the parts of the image that are black so uh to show you what that means if i uh open up the adjustments here and apply saturation and lightness you can see that lightness is applying to the stars and the galaxy but not to the background right okay so that is fine to do i'm going to go ahead and whoop too much i'm going to boost the saturation of those a little bit and you can see the stars got a little bit bluer and things like that but what we really want to do with this for everything to stand out is to desaturate the background a little bit so let me go ahead and duplicate this layer this hue slash saturation adjustment layer layer duplicate layer and then i'll call this one desaturate bg that's not what it did at first it just made everything super saturated but let's go ahead and invert the layer mask so i'll just pull it up so you know what i mean um so here it is to invert it i can just press command i on mac or control i on windows and it inverts the colors if we exit back out of that you can see that made um the the colors of the background uh quite distinctive and one thing to note here is that in addition just to the random color noise we do have a little bit of a blue problem right around the galaxy so we might have to deal with that later or maybe not we'll see so this is sort of crazy right because we wanted this to desaturate and because we duplicated it's now saturating so let's go ahead and bring this down and bring uh lightness down as well okay so we're getting somewhere right um there's a little bit of a green bias to the picture um i don't know if you can see that so at this point i'm going to apply a curves adjustment layer just to everything and i'm going to just play around with this green a little bit and for some reason the galaxy is looking pretty good um for some reason that green cast is mostly in that corner so i'm tempted just to crop again um because i don't think that that corner is adding much anyways so i'm going to do that i'm just going to crop in a little bit okay um we are getting somewhere let's go ahead and try just duplicating both the desaturate and the saturate layers just to make the image a little bit more punchy so there's more saturation there's more desaturation we still have a bit of a color balance issue here so let's go a little bit more extreme and open up color balance um this is a color balance adjustment layer and i'm just going to uh play around with these a little bit we're getting somewhere um i do like the color of the galaxy that this galaxy should have a sort of um warmish yellow center with more blue uh bluish white spiral arms so that's actually looking pretty good um but the the star color is not that great i think we're still just too a little green on the stars let me open this curves back up see if we can yeah bring that green down even a little bit more okay um i'm going to now go ahead and just do some final little adjustments here um i want to use my mask again uh so i'm going to go ahead and open up another curves adjustment but i'm going to option drag my mask on to it and say yes replace the layer mask open this up and basically what i'm doing here is i'm looking at the galaxy and i'm just going to drag this up a little bit until i think that looks about the right brightness so here's with it off here's with it on just to make that stand out a little bit more and i'm going to do the same thing with the background it's a little bit too bright right now if you're a numbers person what you can do is open up info and then click on down here to the second stretch and if you move your mouse over the background um right now we're peaking on at around high 30s to 40s and i'm comfortable with bringing that down into the 20s so let's open up another curves layer this time we're going to option drag or alt drag the uh layer mask from one of these desaturate adjustment layers to replace it and i'm just going to reset this black point just a little bit okay that's before after and when i'm doing that before after i'm actually noticing that i think the background is a little bit too red so i'm also going to go ahead and open up a selective color adjustment here and drag that on again and go into the blacks and take out let's say minus three on the magenta minus one on the yellow and let's do plus two on the black okay um it's close the the one thing i'm not liking is that the the the stars over here look too blue i'm not sure how that happened probably something in the gradient removal step went wrong um but let's try to fix it uh in a hackish way um so what i'm going to do is i'm just going to make a new color balance layer and i only wanted to apply to this side of the picture so i'm going to draw a gradient on the mask uh the default gradient is black to white so if we just do something like that oh wrong mode uh if we just do something like that and then look at it you can see it's only going to apply to that side of the picture where we have the stars that are too blue and then i'll open this up try to fix those stars a little bit now of course this created a new problem because the background looks crazy now but let's go ahead and uh fix that by just making a new selective color layer dragging that onto there go into our blacks and remove and just play around with these four sliders until it matches the rest of the image a little better we're close i still just this very edge now i just did this big bright star up there and the the fact that this is now a little bit darker than the rest of the image is bothering me so in the matter of time normally i might try to fix that but in the interest of time let's just crop it okay i like it so we're getting close we got a couple nice bright blue stars done here but we have some star color the galaxy is looking really nice last thing and just some final touch ups here we still haven't dealt with our dark streak right there i think that was it maybe that's it for final touch ups so to deal with that what i'm going to do is i want basically what we're seeing as its own layer and this is a weird command in photoshop i don't actually know where it is in the menus someone asked me to show everything in the menus as i'm going i'm sorry i don't know where this is in the menus but the keyboard shortcut is command option shift e or that would be control alt shift e on windows so command option shift e on mac control alt shift e on windows and what it does is it takes everything that you're seeing just the visible and merges it and makes it its own layer on top that's very helpful so i'm going to call this touch ups and what i want to do is basically select that um that part of there that's this dark line um and brighten it a little bit so i'm going to create a new curves layer and with the layer mask on the curves layer selected i'm going to grab my brush tool and i want a zero percent hardness brush or the softest brush available and then i'm going to make my brush size just a tiny bit bigger than the line itself and i'm going to go ahead and and let's do i don't know 75 percent about opacity and then i'm just going to draw in that line right there show you what it looks like okay so pretty close to uh where the line is let's see now if we can fix this up with curves and we might have to touch up the mask a little bit after so i'm going to just pull oh sorry we have to invert it uh because right now it's doing everything to everything else uh but we want to actually just have it apply to that line so i'm going to invert the mask now it looks like that and now we can apply our curves adjustment and that's it uh maybe nope too much down there okay i think we did it in one yeah that's not noticeable anymore um so all i did was drew out where it was on using a mask and then applied a very small curves adjustment to even out that spot okay i think we're done it's looking really nice i like the spiral arms of the galaxy the star color is okay considering how much light pollution we had and uh we still have a fairly nice wide field of view i know we've done a lot of cropping to fix problems but that's how it goes sometimes uh let's go ahead and show saving so if i do file save the default option is going to be tiff because that's what we brought it in as tiff is a good option if you're planning to bring this into any other program or for long term archival storage i'll go ahead and cancel though let's do save as and save it as a photoshop file and i know i should have been saving as a photoshop file as we went but i forgot got too excited so anyways let's save as a photoshop file i'll go ahead and embed the color profile um that's fine call a psd okay and then i like the save for web option for saving off jpeg or pngs um in photoshop c is six it's still a main option under the file menu i think in newer versions they might have moved it to export or somewhere else um but look around for it in the file menu because it's really nice what you can do with the save for web option is change the size of the picture i'm not going to use that feature but if you wanted to you could change it right here um you can make sure that it's converting to srgb which is what you want for saving to the web and you can you have all the different web friendly options up here png jpeg gif um i'm just going to save it off as a 100 quality jpeg at and that makes it about 2.1 megabytes i'll just save it to the desktop here okay if we hide photoshop open it up in preview make it full screen okay and there's our final image of m101 the pinwheel galaxy and yes there is still some noise in the image of and definitely noise in the galaxy itself but all in all not too bad a job considering the conditions this was about three hours from a portal nine zone with a 60 millimeter refractor um and i actually think it's a pretty nice image we do have some interesting variety of star color i don't know how accurate these star colors are photoshop doesn't have any kind of photometric calibration in it but it's still uh i'm still i still really like this image um and i hope that you've learned something about uh processing through this i know there were there were probably more steps in photoshop than in previous tutorials but uh we had to do a little bit more heavy lifting to deal with the light pollution here but hopefully this may be useful because i know a lot of people live in cities and and still want to do extra photography this has been nico carver from nebula photos dot com um and i hope that uh you subscribe uh if you stick around a little bit you'll see all of my patrons on patreon uh i always put um everyone in the credits so if you're interested in joining me on patreon the link is in the description until next time clear skies