When evaluating flats I get very different adu numbers using PI v. Maxim. The procedure for each is very similar. In PI I draw a preview and I use statistics/16 bit which is basically the same operation as in Maxim, drawing a box and using the info window. However, the numbers for Mean ADU are as follows for a given flat frame drawing the preview of the entire frame in each program:
PI: 15856
Maxim: 24654
I capture sky flats using CCD Commander and set the mean adu to be 25000. This number agrees with what Maxim is telling me, but not PI.
Thoughts?