Hi, I use an ASI 1600 MM cool Pro CMOS camera. On a 16-bit scale (65550 total adu output) I try to keep my Flat adu to about 1/3 of total, or about 20,00 - 24,000 adu. I understand that this will keep the flats in the linear range of the camera's response. Sometimes however, my flats will leave white-ish motes instead of the dark motes that I would have if no flats were used. I usually use 30 single flats to integrate into a flat master in PI.This issue has happened twice now with my Ha filter.Question:1. Has anyone seen this before ?, and2. Is the fix to lower the adu read out for the individual flats to say 15,000 adu.Thanks for your comments.Bob