Vince,
Circling back to re-visit this topic;
I was able to use the Artemis software to find and check the "even illumination" setting you mention, which did eliminate the severe gradients on my light-table flats.
Re-reading the user manual on this topic leads me to ask a follow up question about the implications for capturing the various types of calibration frames. For short-exposure calibration frames (flats, flat-darks, bias) I'm assuming it makes sense to have the "even illumination" setting checked.
However, based on the comments in the user manual, for deep sky science frames, and dark frames, it sounds like those captures would be better captured with "even illumination" unchecked.
Am I reading this right?
Thanks.
Steve Bennett