integrated image peppered with dark pixels...

[astropixel]

Hi. Stumped on this one. I've followed Vicents instructions and tried two different sets of dark and bias frames, along with various pixel clipping, but no luck - just shades of better and worse. Not using a dark fixes the problem, but that's not much help...

10 darks 5 mins each - 40 bias  - 10 flats. The bias and flat seem to be doing their job. Not sure where to go with this one.

Help gratefully accepted

[yock1960]

It looks to me as if the temperature of the darks does not match the lights. I do not use Pixinsight to calibrate, but I would see this from time to time with my DSI-III & Nebulosity. Scaling darks did not work well due to the amp glow of the camera. Even when I used it with the amp turned off, scaling darks was iffy...I'm not sure why...probably because the DSI-III is not temperature regulated and a set of darks could have temperature variation in themselves as well as the lights.

Steve

[astropixel]

Thanks Steve.

Temperature is not supposed to affect dark calibration in PI so I'm not sure. Perhaps that is the case. It's a cold night tonight so I will cold soak the camera and try again. Winter temperatures are quite stable here so it will be very close.

[astropixel]

Same problem. However, fixed dark pixels by percentile clipping dark integration. Problem now is master dark is not removing hot and cold pixels. Perhaps pixel rejection is too strong.