That depends entirely upon factors of the entire imaging system. Personally, I use a small sensor webcam, because that's what I have. I'd encourage you to use whatever you have, and see if it works for you. If you don't have any camera, then that's a different story! In that instance, I wouldn't invest in one of the largest sensor cooled cams, which can run lots of thousands of dollars and in fact are relatively inflexible for spectroscopic purposes. A simple 1.25" adapted cooled monochrome camera, with a medium size sensor, like an ASI183M, would doubtless work well in most situations and not break the bank.
