Last night after a short exposure of M81 I did a 600 s dark frame and found every pixel to be saturated. Tried again with same results. Biases and light frames seem to be fine. Tried some different exposure times on darks and found that if I go down to one second the counts are around 49,000 with a noisy pattern. This was in a dark dome at night. Camera was cooled to -25 C. Tried CCDOps and The Sky X to acquire images with same results. The cooler was working harder than usual at 70- 80% because I did not accurately predict the ambient temperature in the dome. I tried some other temperatures this morning without a significant difference. Because the biases and lights are OK I don't think it is a shutter or read problem. Obviously not a software problem. I have not shut down the camera yet (observing remotely) but plan on getting out there today to take a closer look. Any thoughts would be appreciated. Thanks, Bill Camera: SBIG STX 16803
