I encountered quite a few problems this term in the process of learning how to take images. One night none of the available computers would recognize a camera. I got a lot of great viewing in, but no images. The moon was gorgeous that night so I was very disapointed. Another night we took two hours just to focus the camera because we were all confused about exactly what we were doing. Another night I was doing okay, but I wasn't sure when I had the camera focused and there was too much dew. All of these problems resulted in a number of images that have major problems. Here are a few and what I think the problem was. All of the pictures below were taken by me alone so all the problems are the result of my error only.
This image has two problems. Number one the camera is clearly not focused. I am not exactly sure what I was thinking, but the fact that Vega still looks like a donut is clear proof that the camera needed some more focusing. Then of course there are these horrible white streaks almost as though there was some very organized aurora going on. Anyway while I was puzzled a first it soon dawned on me that I was reusing the darks. For those of you who don't know what that means let me explain. A dark image needs to be taken to elimante electronic signals from the camera itself which the CCD camera might mistake as light coming in from the star. The dark image is subtracted from the final images to remove the electronic noise from the camera. In this case that noise was not removed. Or at least thats what I think happened.
This was taken on the same night with the unfocused camera. So part of the problem is most likely the camera focusing. I believe that I was taking a new dark picture by now, but I might have been wrong at the time. None of this seems to explain the problem of the scattered background noise. I am seeing two many really small stars in the background in this picture. My only explanation is that there was dew on the telescope by this time. This might account for the blurred image. Or the temperature on the camera was too warm. The camera often had a setpoint that was too high. It shouldbe around -20 and it was probably closer to 13 or something like that.
Well, I hope you like some of my big mistakes. Happily I now know how to avoid these problems in the future. Now if I only had a telescope at grad school.