I have a ZWO ASI183C pro cooled OSC. Generally, I like this camera and for me anyway, there has been somewhat of a learning curve to navigate. I have made progress though.
Anyway, I was doing some experimentation with this using an 8" f/4 Newt. I am trying to improve star shape and color in my images so I thought I would try dropping the gain down to 0, which in the ASCOM software for this is a pre-set for highest dynamic range.
In this experiment, I did 130 frames @30s each using gain of 0 with a sensor temperature of -15c. I calibrated using 50 darks, 50 flats, and 500 bias frames. I processed this in DeepSkyStacker.
I was expecting a lot more noise than I get when I run at unity gain but this vertical banding took me completely by surprise. I've never seen this before in any camera except a Nikon D700 that I've used in the past.
The attached jpg has been reduced in size. It is simply the TIFF opened in Pixinsight and autostretched and saved as a jpg.
Anybody have any insights into this? I guess mainly, I want to determine if it may be a problem with the camera or just that this particular combination of exposure, gain, calibration, etc. is just not good with the ASI183C.