Im working now a few months with the ASI1600MM-Cool and had some good results. However when I image very faint objects with a long series, it shows faint stripes in the direction of the drift.:
Camera ASI1600MM-Cool at -35 degrees.
93x images stacked of 100 seconds each, binx2, all guided
Gain at unity gain.
36x bias applied taken at -35 degrees, binx2
80xflat applied taken at -35 degrees, binx2
34 dark applied taken at -35 degrees, binx2
I see this in all my images also the older images. Taking new flats, bias and dark's doesn't help. It only becomes visible when I uses very high contrast settings on the final stacked image. The stripes are under the same angle as the drift of the camera after a total 9300 seconds of about 32 pixels in X and 10 pixels in Y due to not perfect pole alignment.
Problem occurs if I stack using Deepsky stacker or MaximDL.
It happens both with a CLS and H-alpha filter in place, so it doesn't seem related to the filter. As a test I also stacked my flats and older darks as if they where images but the strips don't occur then, so it must be related to the small drift (not perfect polar alignment) and imaged stars. Could it be some electron leaks or memory effect in the image chip or software??
Anybody has the same experience and a solution? I didn't have the problem with my older QHY8 CCD camera.
I have also added an older image of M33 showing the same problem but less clear since M33 is bright enough. But careful inspection will show the same stripes.
Han
