Filters on unmodified DSLR

Alex Lutes · Oct 22, 2025 at 11:57 AM

So, I'll get straight to the point. After much processing, I've come to the conclusion that I have a very limited area of ​​sky unaffected by city glow. Ironically, this is the southern sector of the sky, where, in my opinion, the DSOs are the most beginner-friendly. I'm starting to think about two- or three-band filters for my standard Canon 6D to at least increase contrast at the expense of increased integration time. Maybe someone can suggest a filter that would work for me, or maybe this whole idea is a bit silly?

Definitely not silly, but I don’t know if this is the best use of your money and time.

I also had this same dilemma to deal with a couple of years ago and I ultimately went with a budget cooled osc (SVBony SV405CC). I chose this for the ability to create dark(s) libraries and to further automate my capture process. Likewise, my unmodified Canon T5i just wasn’t up to the task.

Thomas · Oct 22, 2025 at 02:11 PM

So I’ve used the Astronomik Clip In filters back in the day. I had an unmodded Canon EOS 750D and was shooting from heavy light pollution in the Denver suburbs. The Ha and Oiii filters were definitely useful and I could see a big difference when using them. The CLS one worked well also but my biggest bang for buck was definitely the Ha clip in filter. Don’t expect anywhere near the results you would get using a cooled astro camera with narrowband filters but the clip in ones aren’t half bad either.

Great points, especially regarding managing expectations with the results you’ll get with an unmodified DSLR versus a cooled astro-camera.

I will also elaborate on my prior post in saying if you are interested in mostly galaxies and star clusters, then a stock DSLR with clip in filters is fine. However, if you’re looking to capture emission nebulas, you’d be better off with moving to a dedicated astrophotography camera (cooled or astro modified DSLR). I speak from experience in that I struggled to reach what I wanted to do by trying force tools to work for purposes that they were not designed to do. I used to “image” with a stock Canon T5i and an old Celeston C8-N on a beat-up Celestron CG-5ST. I wasted a lot of time and effort trying to make that set-up work.

I would recommend getting it astro-modified - I did for my Canon 70D and have used narrowband filters with great results. It wasn't expensive, especially compared with buying a cooled astro camera (although I now have one of those too thanks to eBay), and I found it really increased the quality of my images.