 Hello, welcome. This is Nico Carver from NebulaFotos.com. This is part 2B in my series on capturing the Pinwheel Galaxy. If you haven't watched part 1, the link is in the description and you can just watch the first hour and 22 minutes of that all about the capture process before switching over to this video, which will show how to pre-process in a program called CERL, which is an open source and free processing software that is available on all platforms, basically imaginable. It's basically any Linux OS, Mac OS, or Windows. So I'm going to start here. I just I've opened up the website CERL-S-I-R-I-L.org and just to show you the different download options. So if you go up here to the download menu item and then scroll down, the first thing you'll notice is that it is free, but they do accept donations via PayPal. So you can donate right there. There's a couple options right here at the start about downloading scripts and installation from sources. Just ignore these because if you keep going down, then it says choose your OS and most of these packages will include both the program and some of the scripts. So you can then click on any of these operating systems. The first seven here are all Linux operating systems, and then we have Windows, Mac OS, and then a few others. So I'm on Mac OS, I'm going to click Mac OS, and you have the option of installing via Homebrew, or you can just download the zip file and drag and drop the application to your applications folder. So that's what I'm going to do. I'll just mention here while we're on this page though, that if you're on Windows, you can just download and install their file right here, the automatic installation, or if you're on one of these Linux OS, they are mostly available through very common package managers like the advanced package tool on Debian or on Ubuntu. So it shouldn't be hard to install, I wouldn't recommend installing from source or anything like that, I would just use one of these pre-packaged things down here. Okay, so we'll get this all installed and then jump right in. Okay, I've now installed the program and opened it up, this is what it looks like when you open up the program. The first thing that I found out about it is that you can do a lot of things manually just using these tabs up here, or just like PIX Insight, people have written scripts that allow you to speed up your processing by taking care a lot of the manual tasks for you more automatically, so those are available under scripts. And the first thing that I tried, and there's more scripts available than this, but these are the ones that it comes with initially. The first thing that I tried was this DSLR pre-processing, because that's exactly what I want to use it for. And if you just click on it, instead of giving you any information or letting you pick your files or something like that, it just right away runs the script. But this is sort of cool, this is a little console here that shows you any errors or things like that. And I can quickly see by reading through this little log of what the script did that it's expecting for me to set a working directory because it couldn't find anything in my pictures file, which I guess pictures directory or folder, which I guess was the default working directory that it was expecting, then it the script failed. And I know that because down here in blue, it says script for DSLR color camera pre-processing needs four sets of raw images in the working directory within four directories biases, flats, darks, and lights. So what I've done is I've created a folder here on the desktop called M101. And inside that folder, I've put biases, darks, flats, and lights. And you can download all of this data from my website, the link will be in the description. So you can follow along with this or use your own data. But the key thing here is if you're using this script is you need a working directory or folder, and then inside that folder, you need four sub folders with these exact names lowercase, biases, darks, flats, lights. Okay, so how do we set the working directory? What we do is we go down here to this blue button that says change dur dot dot dot. And if you hover over it, the little tooltip tells me change current working directory. So that's what we want to do. I'll click on that button. I'll go to my desktop and click on M101 and click open. And here in the log, it says we changed the current working directory to users, CFIUS desktop M101. Great. So now let's try running the script again. So I'm just going to go up to scripts DSLR preprocessing. And now what happens is you can see it's immediately taking those files and doing something with them. It's reading in the bias files and gives you some information about them and it's decoding them. And right down here, it gives me a little one liner about what it's doing right now. So it is converting the raw bias files. And then down here, there's a little progress bar. And just like with deep sky stacker, if you've used that program, this progress bar does not indicate the entire process, but the current task. So the current task is reading in and converting all of the bias files. And so it's almost done with that part of the process. But as soon as it finishes that part, it will move on to the next part of the script, probably taking all those bias frames and putting them together, then moving on to the darks, and so forth. So this is going to take a while. Yep, you can see what it's doing now is it's stacking the bias frames. I know that because right there it says stack bias. And so again, this will take a while. You can watch it as it goes if you want to, or you can just leave it and come back. I don't know how long it'll take, maybe an hour or something like that, maybe longer because we are working with a lot of files. But anyways, I'm going to skip ahead in the video until this is all done and we'll see what it puts out. Okay, it has finished with the script. And it tells us right down here at the bottom of the output log that the total execution time was four hours 41 minutes and 23 seconds. So for 383 images, so for 383 images with full calibration files and everything else, that's how long it took in serial. I'm working on a MacBook Pro that's a few years old. Okay, so it finished, but where is our image? Well, if we look in the M101 folder, you can see we now have a new file called result dot fit. And the reason if you recognize this icon, this is the pics inside icon is because operating systems usually have something called the system viewer, which basically means what's the default open command. So on my system, the default for fits files is pics inside, which is why we're seeing that icon. But we can also open it back up in serial. So if we go to the file menu and choose open, this is something I find a little confusing why it's grayed out here. I feel like this should just be set to any files. But for some reason, it's set to raw DSLR camera files, you have to click in here and find fits files. And then you can select it and open it. Okay, and serial opens up two windows. We have this window, which separates out the red, green and blue channel. And we have this window, which is a composite RGB image. And we're not seeing anything right now, because this is still in its linear state. But if you go down here, you can see there are a bunch of different options, actually, for a preview of what it would look like if you did stretch it with auto stretch or arc science stretch or whatever. So we can change it from linear to something else. I'm just going to choose auto stretch. Okay, and now you can see this bright green image. The reason we have this black border along the bottom and on the right is because there was some drift through the night. And serial doesn't chop that off for you. So it is all registered, but it's just leaving the full frame. And that's why we see that that edge, we can easily crop that out later. Okay, the other thing that's interesting is we've turned on the auto stretch, but nothing seemed to happen in the red channel. But let's check out the green channel. Oh, really bright. And the blue channel looks more normal. So in this case, the red channel was really weak compared to the green and the blue. That's reflective of my local light pollution. So it's nothing to be too worried about. In any case, there is a lot of things that you can do actually right in serial with this image processing menu. And we can try some of these out. It does have a color calibration and a photometric color color calibration. Let's just try. Actually, I'm interested what this is. So let's see here. Image parameters. Let's type in M101. Find pinwheel, that's correct. Our focal distance was 360 and our pixel size was 6.25 microns. Let's see what it does. Okay, it took a few minutes. I think it's done. It doesn't say done in the output log, but it did change the image. And it does look a lot better, actually. So that was well worth it. Let me actually zoom in. Wow, look at that. This really worked. I don't like the zoom feature, but that looks good. It really brought out the blue in the galaxy and the star color looks good, too. So actually, let me explain what that just did. What it means by photometric color calibration is it looks for stars in the field where they're of a known color. And then it takes those and it bases the rest of the colors based on those stars having a known color. And so it's also a feature in Pix Insight, but I didn't realize that it was here in Serial. So this is really great. I'm going to go ahead and close that. And actually, I really even just like this auto stretch. It looks really good. So let's see if we can figure out how to apply the auto stretch. I'm going to go back to linear for a second. I'm going to go up to image processing and down to histogram transformation. There's our histogram. And if I just want to apply the auto stretch to the image, I can click this button and then click apply, I guess seem to work. Wow, that's really nice. So actually, this program has turned out to be really, really great. I'm surprised I haven't used it before. The one thing I don't like about it is that the interfaces are quite clunky. I'm having trouble sort of understanding how to zoom and know which one should be on top and that kind of thing. But other than that, this program is really, really good. I don't know everything about it yet. So just bear with me. Let's try this remove green noise next. Is that of a dialogue? Maybe? There it is. Okay. This is the recommended option in most cases. Okay. I never, and I can't change the amount. Okay. Well, let's just try it. Yeah, like that. Sure. Okay, let's see what else is in that image processing menu. Oh, there's a background extraction option. Okay, let's check it out. Okay, so it's very similar to Pixinsight's automatic background extractor. Let's try it. So that's where it's placing the samples. Can we... Oh, you can also set samples manually. Left click adds samples while right click removes them. Can I just move a sample? Oh, well. Let's just try it with these, with this automatic generated samples. Apply. Close. Wow. It's pretty good. There's still, you know, there's still some gradient stuff down here, but that's really where, like, you know, the frames are overlapping. Overall, that's quite impressive. Just want to try to see the galaxy up close. Where are you? Just zooming around and seeing all these background galaxies. There's another one. It's a little bit, it's a little bit not saturated enough for my taste, but other than that, this is really impressive. You know, I can't say I know how to use some of these other ones, so I'm going to stop there with this and we'll move on to GIMP. But really, there's actually not that much we have to do in GIMP at this point because Cyril took care of all the heavy lifting of by removing the gradient and balancing the colors. So with a, you know, really easy automatic processes. So this is really nice. I didn't realize how powerful this was. It's sort of like it has some of the best features of Pix Insight in a free program. Okay, as and for bringing it into GIMP, I don't want a fits file. I want a TIFF file. Now, you might be more familiar with like JPEG or PNG, but those reduce the accuracy down to eight bits and add JPEG is a lossy format as well. So you really want to TIFF file here for moving it to GIMP. And so I'm just going to call this M101 Cyril. It did finish. Let's see if I can open it, then it's done. Yep. Okay. So let me close out of Cyril now, quit Cyril, or maybe just have to hit the little red button. Are you sure you want to quit? Yes. Okay. Okay. And then let's open this TIFF file in GIMP. And the first thing I'm going to do is I'm going to crop this to just this central part. There's a lot of weird stuff going on along the edges, registration artifacts and strange banding and things that we don't want. And I also feel like the galaxy gets a little bit lost when it's so swamped by this image scale. So I'm just going to open up the crop tool. It's the third row down four over from the left. And I'll zoom in here on GIMP. You do shift equals or plus to zoom in and minus to zoom out. And I'm just going to find a section like that. Okay. I'll hit return to accept the crop. And then I'm just going to go ahead and duplicate this in case I mess up anything. So to duplicate, you can just right click on the layer over here in the layers panel and choose duplicate layer, or you can go up to the layer menu and choose duplicate layer from there. I'll call this duplicated layer curves. And I'm just going to open up the curves command from the colors menu. And I'm just going to reset the black point here just by moving this the black point the shadow the point all the way over here on the zero over. And basically what that does is it resets this point as the zero point. I'll hit OK. And let's just try now applying a little bit of an S curve. So I'm going to go back to the curves command colors curves. And I'll just drop a point down here sort of in the blacks, bring that down. And then a drop a point up here on the other side of the histogram and bring that up a little bit. And you can play around with what looks good to you. It looks pretty good. Hit OK. All right. I think at this point, I might want to duplicate again. And I'm going to call this saturation. Okay, I'm going to zoom in on the galaxy. And I'm going to go back to the colors menu, go to hue slash hue dash saturation and just try bringing up the saturation value. I'm going to bring it up to I'm going to max it out to 100. I think that looks really good. You can see the blue arms of the galaxy. You can still see the nice yellowish core. That looks really awesome. Okay, I'm going to click OK. Let's zoom back out and see what it did to the whole image. It did bring out some of this color noise in the background. If that bothers you, you can definitely deal with it. Let's do this. Let's duplicate this layer again. Just right click and choose duplicate layer. And I'm going to call this mask. And what we're going to do with this mask layer is we're going to zap the color. So I'm going to go to colors, desaturate, mono mixer, just hit OK. Now we have a nice luminance mask here. And we want to make the luminance mask a little bit more aggressive. So let's bring up the levels and just do something like something like that. So what I'm doing is I'm basically just knocking out the background by bringing the shadow slider way over here. But I also brought in the mid-tone slider a little bit to the left to preserve the brightness of the galaxy and the stars. Okay, and then because I want to use this mask to target the background and protect the saturation in the background and protect the galaxy and the stars, I'm going to invert it because white selects and black protects. So we want the sky to be white and everything else to be black. So I'm going to go up here to colors and just click invert. It looks like that now. And I want to apply this mask to a new layer. So let's go ahead and duplicate this saturation layer. I'm going to call it dsat bg for desaturate background. Then I'm going to select this mask just to select all. Copy it. Just do copy visible. And then I'm going to click on the dsat bg layer and right click on it and choose add layer mask. And it doesn't matter yet what I pick here. I'm just going to click add. Just do a white layer mask. Then I'm going to click on it. Just left click. And I'm going to paste. So on a Mac that's command V on Windows it would be Ctrl V. It paste in as a floating selection and we just want to anchor that down into the mask. So I'm just going to hit this anchor, this green anchor button right there. And what that did is now the mask is, that we created is now the layer mask on this desaturate background layer. So let's go ahead and turn off the visibility of the mask. The reason we're still seeing this is because I alt clicked it, but we can turn it off just like that. Okay. And one thing I'll point out here in GIMP is when you have the layer selected, you'll see a yellow dotted line around it. And when you have the mask selected, you'll see a green dotted line around it. So now with this layer mask applied, we want to select the actual image in that layer. So we want the yellow dotted line. And now let's desaturate and darken it a bit. So I'm going to go back to the colors menu, choose hue dash saturation. And I'm going to turn down the saturation and turn down the lightness. All right. This is looking really good. I think the best yet we'll see if pics inside can beat this. I'll hit OK. And this is looking good. Like I said, there's still something that's bothering me, which is this streak right here. I think what happened is something went wrong either with the flats, like I turned off the camera and the sensor got cleaned or I don't know what happened. But anyways, what happened was that there was like a dust mode and then the dust mode got streaked because of the drift in the system. So I want to fix that just by evening it out with the rest of the background. And the way we're going to do this is open up or create a new layer from what we're seeing right here. So if we go to new, if we go to layer, there's an option, the layer menu, sorry, there's an option for new from visible. So go to layer menu, choose new from visible. And it creates a new layer called visible. I'm going to rename that touch up and I'm going to add a new layer mask to the touch up layer just by right clicking and choosing add layer mask. I want to make it black. Full transparency is what it says. And then I want to paint on this black mask, a white brush stroke right there. So with the mask selected, I'm just going to grab my brush tool over here in the tool panel. I'm going to bring the hardness of the brush down to zero, mine already is, but if it isn't turn it down to zero. And then just bring your brush out here onto your workspace. And we're going to try to make it the right size so that it's the same width as this aberration. So right now it's a little bit too small. So I'm just going to increase the size just a tad a little bit more. There we go. And then I have white selected, that's the foreground color. And then I'm just going to draw where I see that aberration just like that. If I look at the mask now just by doing option click or alt click, that's what I drew in. Looks like I went a little bit overboard over here. So let me just try to even that out now with black. I just press D to get my black as the foreground color and I'm just going to even this out a little bit. Let's look at it again. It's looking pretty good. I just want to get a little bit of white now down here. I'm just going to hit X to switch the foreground and background color and paint that in a little bit. Okay, almost there. Painting in black a little bit right there. Okay. So now that I've painted in that mask, let's now actually click on the image part of this layer. So you should see a yellow dotted line down here. And let's go back to the colors menu and go to curves. And I'm just going to bring the curves up a little bit more until it's basically the same color as the background around it. Now you can see there's still a little bit left over where I need to paint in the mask a little bit more. So I'm going to click back on the mask. I'm going to grab my brush again. Have white selected again. And I'm going to make it a little bit smaller and just paint in those parts that I missed. Okay, that's looking really good. So I've evened out that background. Let's go zoom back out and see if we can see it. Nope. I think that really did the trick. So now I'm just going to do one final curves. So I'm just going to do another layer from visible. And I'll just call this final curves. Do colors, curves. And I'm just going to reset my black point one more time just a little bit. And just a little bit more. And then just do a slight s. Yeah. So that's pretty subtle. Let me just bring it down even a little bit more. Okay, I like that. So this is just about finding the right black level, basically. So I hit a point right here so that I wouldn't change this up here. And then I just did two little points down here in the shadows and just lowered those a little bit to just try to get this dark sky level at the right darkness. Okay, I actually think this is our best yet. I'm going to go ahead and save it. If you want to return to it in GIMP, just do save the normal save command and I guess I will. Sure, I'll just call it M one oh one zero. And GIMP. Okay, and then I do the export to save it as a JPEG. I'll just change the file ending here to JPG to do export. I'm going to do 100% quality hit export. And we can quit out of GIMP now and open up our final result. Just make that full screen. And so this is really nice by using serial to do the color calibration and stretch and background extraction. We got a lot more detail and good color out of this. So I think that I am going to probably stop doing my normal thing of doing deep sky stacker plus Photoshop and deep sky stacker plus GIMP and just switch completely to serial because it just has some killer features that are very similar to what we get in pics insight that I think everyone will really benefit from. So this has been an amazing video for me personally and hopefully you got something out of it too. All right, till next time. This is Nico Carver from NebulaFotos.com. And in just a minute here, you'll see all the people that support me on Patreon. If you want to support me on Patreon too, the link will be in the description. Thanks so much. Clear skies.