I have been away from imaging for a while. I noticed that my dark frame now has a horizontal light band that is near the bottom. This wasn't there in 2016. Is this as simple as the camera needing an adjustment (tune up)? comparative images below. Thanks, Carl
Let's first make sure that isn't simply a light leak. If you're doing dark frames during daylight hours make sure everything is securely covered / capped. The shutter alone isn't enough to block daylight. If you're sure it's completely dark then please post a FITS frame of the bad dark frame.
Just a “shot in the dark” here (pun intended), was cooling enabled and set to the same temperature as for the 2016 dark? The number of hot pixels in the latest image compared to the 2016 image suggests possibly not. Look at the .fits headers for the dark frames, CCD temperature would have been recorded.
I shoot my calibration frames after an imaging run. my observatory is closed up & lights off. The only thing that it could be is my flat field panel. I will try again tonight w/o flat field panel on. Thanks Doug. Carl.
William, Yes, these where shot at -30° according to my calibration folder. My standard exposure time for my dark's are 4 minutes. I will double check the fits header tonight. Thank you for your input. Carl.
Two ataboys for you Doug. I shot a dark frame w/o the flat field box on & it turned out perfect. Strange thing, I have been doing like this for years & never had a problem. Oh well, live & learn. Thanks Doug.
