bergenk Can i use 1.25 filters with a asi1600 at F3.45, without clipping the corners of the sensor?
Nope, if you assume that like the 2" filter drawer, the filter glass is 6mm from the camera flange. And that is assuming the filter already has 28mm clear aperture. Most 1.25" filters fall into 26mm to 28mm clear aperture.
Just use geometry...
The corners will see fewer than 1/4 of the photons that the center of the sensor sees.
f/8 is probably the limit.
Chen
