Preparing my photo system this time. I do not yet have a decent solution to take a flatfield calibration images. Many astrophotographers today, use a convenient EL-foil solution. The foil is thin, and provides even illumination. So It was time get ones for myself also:
A5 EL-foil (white)
I will use these in combination with Nikon D200 & 300/4.5 tele lens.