Hi I own an ASI 294MM PRO that has been working fine for a while. Suddenly a strange dark shadow (or a glowing ring, I don't know which is the problem) has appeared when I turn on the cooler. Over time the bright ring closes and disappears in about an hour. At first I thought it was a reflection that was disappearing as the telescope moved, but when doing a series of darks, surprise! the same problem also appeared, so it could not be a reflection.[upl-image-preview first light of sesion, camera cooled: url=https://bbs.astronomy-imaging-camera.com/assets/files/2021-04-15/1618517264-209611-light-1.jpeg] Last light of sesion, camera cooled: first dark, camera cooled: Dark after 1 hour, camera cooled:
Sorry problem with post, continue: Dark after 1 hour, camera cooled: Dark afer 1,5 hours, camera cooled: When cooler off, dark is normal: i think it could be cooler problem causing ice spreading across the sensor over time. Any ideas to fix this problem? Thanks in advance.
Thanks for the reply. Tested the night before with cooling in stages, first at 0ºC, after a few minutes at -10ºC and finally at -20ºC. The problem persists although it is less noticeable and disappears after a few minutes. The strange thing is that it had never happened before. Would it be advisable to replace the desiccant tablets? Thanks again.
lukfer Yes, you can give it a shot.