Someone was posting a question about what camera to buy. At some point in the thread, someone mention issues of linearity with CMOS and that they should try to buy a CCD camera because CMOS cameras have issues with linearity.
So, I did a linearity test on my ASI183MM-Pro using my homemade light box for flat frames. I took 13 sets of .FIT images, ten in each set, at an exposure interval betweeen 1 to 13 milliseconds in increments of 1 millisecond each. I recorded the average ADU for each .FIT file and then calculated the average ADU of the average ADU for each set of ten.
I set my gain to 0. The way gain works in ZWO cameras is
(Full well capacity)÷(2A/D conversion-1)]÷(10Gain setting÷200)
For the ASI183MM, that works out to be
Gain=3.663 Electrons per ADU
This is divided by 16 to 0.2289 Electrons per ADU when converting from 12-bit to the 16-bit storage of .FIT.