 If you're considering modifying your DSLR or mirrorless camera for astrophotography, you usually have a few different choices. And the goal with all of these mods, as we call them, is to let in more light in the deep reds of the visible spectrum. The issue with stock cameras is that they have a fairly aggressive IR cut filter that rolls off gradually in these deep reds. And that gradual roll off means that the H-Alpha emission line, which is so important for capturing emission nebulae, is only passed at somewhere from around 20 to 50 percent transmission. After modification, you typically pass that line at over 95 percent transmission, and that makes it much easier to photograph these dim emission nebulae, like the Harden Soul, or the California Nebula, or the North America and Pelican. And if you've looked into camera mods, you may have seen terms like low pass filter, full spectrum, HA mod, botter mod, and felt overwhelmed by all of the different choices here. Well, this video will clear up the actual physical differences of these different types of camera mods, but also go into their pros and cons and what to expect from each mod when it comes to real world results under the night sky. And to do this, I'll be showing my results all taken on the same night with these different cameras with the same Ascar 200 millimeter lens, and I'll do some head to head comparisons at the end. To be clear, this video is not going to go over how to modify your camera yourself. If you are interested in that, you can find guides on the web. But personally, I've never done it myself because I don't have a clean room and I don't really have any experience or particular skills with small electronics. So I've always sent my cameras out for modification or bought them already modified. And if you're interested in sending your camera out to be modded or buying an already modded camera, I can recommend astrogear.net. I've had a long call with the owner and he really knows his stuff. I sent him this Canon EOS T7 DSLR for modification. He did a botter mod on it. I've been using it for months and the results have been great. So astrogear.net and my affiliate link is in the description. So let's dive in. To start with, let me just break down the anatomy of the filter stack in a typical stock DSLR or mirrorless Canon camera. After you open up the mirror, light first hits the LPF-1 filter, which is an anti-aliasing filter. Also, so what an anti-aliasing filter does is it blurs small detail a little bit. The point of this is to get rid of moire patterns, but those don't really affect us in astrophotography. The LPF-1 filter also is necessary if your camera has an auto dust cleaning function. That doesn't really matter to me. I usually turn off the auto dust cleaning function anyways, because if you're not careful with flat fielding, that can be a problem. Anyways, then behind the LPF-1 filter is the LPF-2 filter, and this is the filter that needs to be removed in every kind of mod, because this is the one that's affecting the deep reds of the visible spectrum and cutting off some of the HA and usually all of the S2. What I just went over, LPF-1, LPF-2 being two different filters is true of Canon. For Sony and Nikon, it's a little bit different, and often those filters are all glued together in a sandwiched filter style. So that affects the kinds of mods you would do a little bit, but it's the basic same idea as what you have with Canon, that there's different sort of filters in a low-pass filter stack that do different things, and the one that you really have to remove is usually called the LPF-2, because that's the one that's limiting those reds. If you just remove the LPF-2 filter, but retain the LPF-1 filter, that's one of many mods that we might call an HA mod, and it's one of the most popular, because it's usually the cheapest mod out there, and there are a variety of mods that also combine removing the LPF-2 or the entire low-pass filter and then adding some kind of astro specific filter back in internally, and the most typical one you'll see is adding back an illuminance filter, also known as an astronomy specific UVIR cut filter, and those are usually provided by the company BOTR, and the BOTR filter is so popular for modding that when it's used, it's usually just called a BOTR mod, and so that's what I'll call it in this video. In my case, what I had done was I had the LPF-1 and 2 removed, and the BOTR filter added in by astrogear.net. And then another kind of popular mod is the full-spectrum mod, where you remove the LPF-1 and LPF-2 filter and either replace them with clear glass or don't replace them at all and just have a naked sensor. So to review, the types are LPF-2 removal, LPF-1 retained, a BOTR mod where LPF-1 and 2 have been removed, and a BOTR luminance filter is added internally, and then a full-spectrum mod where everything's taken out. And I'll be comparing these three different kinds of camera mods, LPF-2 removed, BOTR mod, and full-spectrum mod to a stock DSLR, and to my Canon ESRA, which is sort of a weird case of a camera that you buy stock, but it's already been pre-modified by Canon, and they charge a big premium for that. I won't dwell on the RA in this video though, because you can just watch my full review of it, where I go into all of the details of what the RA is all about. Including the RA is really just for a point of comparison when we get to the end, when I'm doing comparisons of all the different types of mods. So let's jump into each camera mod, look at the results, the pros and cons, and we'll start with this Canon 60D, which has had the LPF-2 filter removed. If you'd get this mod done by Astrogear.net, it's the cheapest one they offer at $169. Here's the resulting photo, this is 18 photos at 30 seconds each stacked together, and we can compare it here to the stock DSLR on the North America and Pelican Nebulae, and you can see that the colors are pretty different, because when you mod, you're letting in all that hydrogen signal, so on an emission nebula like this, it really helps firm up details even in the bright parts of the nebula, like the Cygnus wall region here. I'd say the biggest pro of this mod is that it's the cheapest, works quite well at letting in more HA, and you retain the LPF-1 filter, which gives some protection from the elements if you ever open the camera up without a lens or telescope on it. It does give, the LPF-1 filter does give those small stars a little bit of a blur, and we'll talk about that next in comparing this one to a 60D that's been, has the full spectrum, meaning that both the whole entire low-pass filter assembly has been removed. I replaced it with an Astronomic L2 UVIR block filter that's a clip-in, and at first glance, it might look nearly identical to the last mod, but the removal of the LPF-1 filter means that if we look at the stars very closely, you'll see that that LPF-1 filter does blur small detail, and without that anti-aliasing effect, we can split stars with the full spectrum camera because the small details sharpen up a little bit. This is a small enough difference that I'm not sure of artistically I care, because zoomed out, like I say, they look basically identical to my eye, but the real advantage of the full spectrum camera is that it's a bit more flexible. I could remove this Astronomic L2, which I use for nighttime shooting, and put in an IR pass filter on front of a lens, like this Hoya R72, and do infrared photography during the day, which I've only done on a few occasions, but it was really fun. I want to do more of it, and so that's a big pro of the full spectrum, is that it's more flexible. The downside is you'll likely pay a bit more to get this added flexibility, because you're buying different kinds of filters and things. So next, let's compare these two that we've done to the BOTTER mod, which is like full spectrum, but then they add a BOTTER luminance filter back in internally, rather than having to use a clip-in or an external IR cut filter. And this makes the mod a bit more expensive, but let's see if it's worth it, over the extra cost of, for instance, just an LPF2 removal. And interestingly, the color rendering is pretty different. We still get plenty of signal, but we don't get as overpowered by the reds. If we go back to the stock camera comparison, you can see it's just a tad closer than with the other two mods. One thing I do wonder is if I used an Astronomic L3 rather than an L2, if that might be more similar to the BOTTER. But anyways, I like this color rendering, and it leads me into my last comparison here, which is the Canon RA. The stars will look bloated compared to the other cameras, because I've cropped down from full frame, and the RA has significantly bigger pixels than these crop sensor cameras, but that's also why it's a brighter image than the others, because of these bigger pixels. But if we can get past those differences, I think it compares pretty well to the BOTTER mod. So let's bring them all back up now and look at some crops. I'd say that the differences are all pretty subtle. With a few small adjustments in Photoshop, I could probably make all of these look even more identical than they do here. As another test, though, I did a daytime shoot out with a lamp set to 6000 Kelvin, which is pretty close to sunlight, sort of a blueish white. And I first put all of the cameras onto full auto, including auto white balance, and took snapshots. And here's the results there. And you can see with modified cameras, auto white balance is a pretty bad idea, except with the Canon EOS RA, in which case it works fine, because Canon's already done a white balance shift in the firmware. So to even the score, let's set a custom white balance with a gray card for each camera before taking the snapshots. And these are the results. So obviously much closer and it really is, they can be used with a custom white balance. If you've enjoyed this video, I'm going to have a part two in this series on camera mods one week from today, where I'll be comparing a modded Canon DSLR to a modded Nikon DSLR. And we'll see if I'm so loud by the Nikon that I want to switch to the dark side of the force. Well, till then, this has been Nikko Carver at NebulaFotos.com. Clear skies.