My recent image of NGC1761 is 9 hrs data although very low in the sky and captured under a full moon so probably not a good target to measure the performance of my mono camera. The image of NGC3199 was not affected by moon glow as much being higher in the sky. As you rightly pointed out the QHY has a lower read noise so I am probably expecting to much from the ZWO camera. The filters I am using are Optolong which may be causing some flaring. I purchased the camera to try my hand at Mono, although I would have preferred the QHY268M, my budget would not stretch to that (yet). Merry Xmas