656nm (HA) critically samples on pixels at the following focal-ratios:
2.4um critically samples HA at F9
2.9um critically samples HA at F11
3.75um critically samples HA at F14
3.80um critically samples HA at F14
4.8um critically samples HA at F18
5.86um critically samples HA at F22
If you're using your 60mm SM60 on your 840mm telescope, it will produce a disc that is 8.4mm in size approximately, so it will fit within the 10mm of your blocking filter. You would need a sensor that is larger than 9mm basically to image a full disc with this in one shot (rather than producing mosaics). If you are using that 840mm focal length, then the effective focal ratio with your SM60 etalon is F14. This perfectly matches a 3.75~3.8um pixel camera. So you could target a few different cameras that have that pixel size and have a larger sensor (1" or larger essentially). This would be sensors like the 533MC (yes color, only because it's not available as mono) and the 1600MM (no need to get cooling, so get the older non-cool version). There are other 3.75~3.8um pixel cameras but they are smaller sensors, so they would not do a full disc.
Alternative, don't worry about critically sampling and just use the largest sensor you can get, like the IMX174, IMX183 (I don't recommend this one due grid artifact issues), etc, for cost. They're only a little cheaper than the 1600MM, but the 1600MM is the ideal camera for your system.
Edited by MalVeauX, 01 December 2020 - 03:03 PM.