Pentax K200D for Astrophotography

As a low end consumer DSLR camera the Pentax K200D is great value. In daylight conditions it takes great photos and is easy to use. However, it is not up to the job for Astrophotography.

The two images below illustrate why I don't think the Pentax K200D is not useful for astrophotography. The first one is the jpg produced by the camera and the second a raw image that has been processed to bring out the detail (only some adjustment to levels and a small amount of curves). I used ICNR and an exposure of 10 minutes at iso 400.

There are three main issues: low sensitivity, amp glow and banding. The amp glow is mainly across the top of the frame. Clearly visible in the lower image is the vertical banding. This banding is not present in dark from so I  have concluded that they are the result of variable sensitivity of the pixels to light. The sensitivity changes mainly across the frame and I found no way to correct for it.      

I think the maximum exposure with this camera is 5 minutes without the amp glow and banding becoming apparent. Certainly by 7 minutes the problems are too great.

The camera is acceptable for some widefield and lunar photography as shown in my Southern Cross and moon images.

I replaced this camera with a dedicated cooled astronomical camera and there is no comparison between the two.

If you have had a different experience with this camera please let me know.  Perhaps I just got a bad one.