Two inch T-mount for DSLR - improvement?

[GazK]

I'm just getting into tracked DSO imaging and I'm very much using what I already have from visual observing and daytime photography at the moment. Which is, specifically, a Canon 80D (APS-C sensor) and a WO Zenithstar 71.

I had a 1.25" T-mount adapter lying around from moon imaging on my 5" mak, so I've been using that. But the WO scope has a 2" rear aperture (with a 1.25" adapter). If I swapped the 1.25" T-mount for a 2" one, would I get more photons to the sensor? Would my images be brighter / better?

 

[michael8554]

APS-C has a roughly 30mm diagonal, so a 31.7 adapter sounds okay.

A 2" adapter might be more rigidly mounted, the less adapters the better.

Michael

[wongataa]

You would only get more photons on the sensor if the smaller mount was causing vignetting and then you would not get any more photons where there wasn't vignetting with the smaller mount.

A 1.5" adaptor should have a big enough hole to completely cover a APS-C sensor so a larger adaptor likely won't have any effect optically.

A larger mount could be beneficial if you don't need any other adaptors if you use it just in terms of reducing parts needed.