Hello, I have been using an ST-8XME cooled CCD camera for several years. I recently noticed that its Bias has been around 1000 counts, which is ten times as high as past years. I got an advice from a friend that increasing bias could be a sign of crucial damage in the future. Should I return my camera to your service shop for diagnosis or need no care? Thank you.
No that is normal. We target 1000 ADU to ensure dark pixels don’t get clipped. The driver software had a feature that tried to adjust the bias down to 100 digitally. It causes issues with some application software and is really unnecessary, so we turned it off by default. It can be turned back on in the SBIGDriverChecker, but we actually recommend not doing that. In short there is nothing wrong with your camera and it does not require service.
