Flats Problem

General
1

Have a problem taking flats with a QHY 268C camera. After taking images with my QHY268C camera, (Photographic mode, gain = 26, offset = 30 using UVIR filter) I took flat frames immediately afterwards using Sequence Generator Pro. Although this camera says it is 16 bit, the camera seems to operate at 14 bit. When I’m setting up parameters using Flats Calibration Wizard, the ADU can’t be set much above 8K or I get a white washed result (for 16 bit I was expecting to set the ADU around 25K to 30K). The flat shown attached that I took in SGP has ADU set to 8K for 3 seconds. These flats looked Ok in SGP when they were generated but when I checked them in PixInsight, they were very dark. Trying to determine what the problem may be either settings I have with SGP or if it is something else.

Anyone else have this issue? Any advice?

2

FWIW, I have a 268M which produces normal ADU readings, for example a mean of 29887. I used to have a 168C and got a mean, for example, of 29626. I used a 500 ADU tolerance in the SGP Calibration Wizard. Is your tolerance set correctly?

Kent

3

So, yes my tolerance is set the same as you; 500 ADU. I did another test this morning using both Sky Flats and a light panel and the flats I got were better for a mean closer to what I’d expected.

Reggie