This is really an age old question. You get your first DSLR or mirrorless camera and you screw it onto your telescope only to find out the Ha response is so low you can’t really image and nebulae with it. Sure, it can be done, but the extra exposure needed makes it hugely impractical. That’s when people go down the rabbit hole of deciding whether or not they should modify their new camera. Here I’m going to break down what that involves and whether or not you should do it. Before I get started, I feel like I should mention that this is a risky process and doing this modification could damage your camera, be advised of that and really consider that before deciding if this something you should try. I do not recommend this unless you know what you’re doing and are willing to lose the money you paid for the camera.

What Do You Do With Your Camera?

This is the first major question you have to ask yourself. Are you going out and doing landscapes or taking pictures of your kids etc.? If you are, leave now and don’t modify your camera because if you do, you’ll end up making it unusable for everyday photography. There are ways of editing the pictures or putting filters back in correct for the redshift in your images, but as a rule of thumb just don’t modify any camera you don’t intend to dedicate for astrophotography.

What Exactly Are You Imaging?

Another important question to ask, if you’re only imaging galaxies and planets, once again ignore the modification. Yes, a modified camera can bring out more detail in a galaxy from Ha response, however I don’t think the risk of damaging your camera outweighs the benefit that brings. Remember, modifying a DSLR involves getting very close to the raw sensor and electronics and any slip up could leave you with an expensive paperweight. Many people take really great images of galaxies with unmodified cameras so if that’s what you want to do keep doing that and buy a dedicated astrophotography camera later down the line.

How It’s Done

So I’m not going to give an exhaustive guide on how to modify each of the many modified cameras and there are a few different ways you can modify each camera so it gets complex fast.

Essentially what you’re doing when you modify a camera is you’re removing the IR cut filter that is put in front of the sensor. This blocks the infrared section of the light spectrum and it includes the 656nm wavelength that belongs to Hydrogen Alpha. Since Hydrogen Alpha (Ha) is what is most commonly reflected by nebulae, blocking that wavelength significantly hinders your ability to take high quality images.

The process involved removing the front casing of your camera, unscrewing the sensor assembly and very carefully removing the IR filter, usually replacing it with a new clear filter. This is an extremely risky process and should not be considered for the faint of heart, I realize I’ve said that already, but I really cannot stress that enough. As daunting as it may be however, this is one of the most significant upgrades you can make to your setup and the results are astonishingly impactful to the quality of your images. I really didn’t feel like I was able to take any images of note until I had a modified camera.

Buying A Modified Camera

If you don’t want to modify your camera there are companies that will do it for you. I generally don’t recommend these because they can be a couple hundred dollars and at that point you’d be better served using that money to buy a dedicated astrophotography camera, but they are there and do make sense if you definitely want to stick to a DSLR.

Other than that, you can go to a website like Cloudy Nights where you can buy second hand modified cameras, sometimes at a steep discount. I got a modified Canon 600D for $125, it had a broken button and was missing the cover for the viewfinder. None of that mattered for a PC controlled camera and it was an absolute bargain. Those deals won’t come up all the time, but when they do you should absolutely jump on them. I actually ended up making about a 75% profit when I sold it.

Conclusions

As I’ve said, if you feel up for a challenge, you can save some money and have a really great result by modifying yourself, but I would highly recommend most people just buy a second hand one. They are very common and aren’t badly priced most of the time. You don’t really need anything better than a T3i, but you can get some noise benefits by going higher end. Once you cross about the $500 mark though, I would say it’s better to go for a dedicated, cooled astronomy camera, the performance will run circles around a DSLR any way you slice it except sensor size until you get to pretty expensive astronomy cameras.