How much cooling should I use?

Cooling the CCD will decrease the the number of hot pixels and the thermal signal generally, but the exact amount of cooling will depend on your own requirements.  If you are using standard dark frames, these should be taken at the same temperature as the the imaging frames.  This means it’s worth imaging at 5 to 10 degrees above the minimum the camera can achieve to ensure you can get corresponding calibration frames when imaging across a number of nights.  However, if you are using dithering or defect mapping to calibrate your images it better to set the camera to maximum cooling by entering a set point below which the camera can achieve.  This will give you the best quality of data.