I’m looking into acquiring a used Canon camera for astro work, and wanted to see if I could get some opinions (usually no problem there, of course). Right now I’m using both a Canon 7D2 and a Canon 5D4 with a ZS-61 on a CEM-40. I would like to use an astro modded camera, but definitely don’t want to modify either of these two since they’re both in use for ‘normal’ daytime shooting (of which I do a lot). Given the investment I have in Canon infrastructure, I want to stay with Canon, so I’ve been looking into the Rebel lineup.
I’ve been browsing keh.com for used cameras, and the prices seem reasonable. I know a lot of folks use the T3i and like it, and KEH also has a full range of used ones from the T3i up to the T7i (with increasing prices, of course). From what I can see, as you move up the line from a T3i to a T7i, very few of the functionality increases relate to astro work. The newer ones probably have better noise reduction, but other than that it seems to me that there’s not a large advantage between a T3i and a T7i when it comes to pure astro work.
Any thoughts on this? Specifically, are there good reasons for going to a T4i (or T5i-T7i) instead of a T3i when it will be modded and used strictly for astro work? Any and all thought on this would be more than welcome, and thanks in advance.
Try what you have, unmodded, for astro work. For red emission nebulae, a light-pollution filter will really help. What you have should work great. Unless you want really faint red emission nebulae, then you would want a modded camera. But if you are willing to put in the extra exposure time (like 3x more total), you can get good results with an unmodded camera.
As you go up from the T3i, every new generation of sensor/processor is going to improve the signal-to-noise incrementally.
S/N is everything. But you can always make up for an older camera with poorer s/n by using more total exposure to increase the signal to overcome the noise.
Whether a T7i is better than a T6i is better than a T5i is better than a T4i, is better than a T3i? Yes. Incrementally.
How much? How much is your time worth compared to the cost of the camera?
Let's say, just for arguments sake, Camera 1 is twice as good as camera 2. But camera 1 costs twice as much.
But, you can take a good pic in one hour with camera 1 whereas you need 2 hours for camera 2.
So it comes down to what you can afford. Your time or your money. If you shoot really faint stuff, it doesn't take long for the mod cost to pay for itself.
Here's an shot of some faint stuff: It's 300 minutes at f/2.8 from mag 20.67 skies with an unmodified Nikon D5300:
Edited by Jerry Lodriguss, 20 November 2019 - 07:12 PM.