Originally Posted by Carl
Is there simple software out there that allows me to see my cameras field of view against a deepsky object?
I'm not sure you'd call them "simple" but CdC, C2a, Halo Northern Sky and Stellarium all let you define ocular and camera FOVs, and are free. This is what I get from CdC with rectangles defined for the guide scope (outer) and CCD on 127ED (inner). CCD Calculator as mentioned by Troy will give you the numbers to feed into the FOV definitions.