Maximum sensor size

[ChrisV (Chris)]

Don't know if I should be posting in astrophotography section as I do live video astro, but need help !

How do I figure out maximum sensor sizes that I can use with my scope & focal reducers ?

Have a WO 80mm refractor (f5.9) and recently an 8" SCT. Currently use a small ASI224 sensor (type 1/3") but would like to try some larger sensors as there's some really nice larger format ones around. I can work out FOV etc, but not sure how to calculate the max sensor size when there are limits set by the tube size. I usually use 1.25" or t-adaptors which I assume act like a field stop ?

And also I often use focal reduction with meade f6.3, and sometimes a lot with meade/optec f3.3. I know this limits it even more but not sure how to work it out.

Thanks, Chris

[Camelopardalis (Dunk)]

It'll depend how good the flattener is at flattening the field. With the 80mm you should be good for at least an APS-C sized chip, and you might be alright with the SCT too...maybe some corner and edge cropping involved. What is usually critical is spacing between the sensor and flattener rear lens.

Stick to the f/6.3 for the SCT as f/3.3 will have too small an imaging plane.

[Atmos (Colin)]

From memory the F/3.3 may struggle with anything larger than your 1/3" sensor, it has a TINY corrected imaging circle. A cheap DSLR is a good test to see what your scopes hand handle.