The ZWO ASI4400MC-Pro is a full-frame cooled colour camera for deep-sky astrophotography. The pixels are 4.4µm in size, meaning if you have a telescope with a 900mm focal length, your field will be 2.29° x 3.51° with a pixel scale of 1.01 arcseconds per pixel.

The camera is equipped with a 44MP Sony IMX366 back-illuminated sensor, which gives a peak QE of around 80%. The analogue-to-digital conversion is 14 bits.

Putting the camera together is straightforward. The camera’s back focus requirement is 17.5mm, and it has an M54 female thread on the tilt plate. An M54-M48 extender of 21mm length screws on to this (or can be replaced by a filter wheel or drawer) and then an M48 extender of 16.5mm goes on (or can be replaced by an off-axis guider). This screws to your coma corrector or field flattener, or other M48 male thread. Alternatively, the two spacers can be placed in the 2″ compression ring on your focuser.