willner1227 avatar
Hello,

First time posting for guidance here, thanks in advance. I tried imaging a wide field with my 85mm Sigma Art lens and my ASI294MC Pro. In the image below, there is a section with what appear to be saturated pixels? Blue and red pixels. While the whole image seems to have evidence of the issue, it's especially pronounced in the one area. Has anyone encountered this before? I'm thinking my subs were too long. I did 3min subs and calibrated with dark and flat frames. Does anyone know any good processing techniques to repair these pixels using reasonable neighboring pixels or what I may have done wrong during acquisition?  
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andrea tasselli avatar
They are NOT saturated pixel. You just had condensation on the sensor (been there) and, alas, there is no saving from it. You might want to check whether some of the single frames are not affect or affected the least and use only those instead. Forlorn hope, I know…
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Fabio Guerceri avatar
I confirm, is a dew problem on the sensor of ASI294. My solution is dry/sobstitute the desiccant tablet inside the camera; or if the desiccant is ok, try to go down the temperature slowly and don't too much cold. In the summer when the envirolment temperature for me is around 30°-32°, i go down step by step of 5° and i stop on -5° not over.
During the shooting session if you view this effect, you can return the camera temperature up to 5-10° and when the effect disapear, go down slowly and stop it before the previous temperature.

bye
willner1227 avatar
Thanks for the help.  I will change the desiccant and adjust my cooling practices.  This is how you learn I guess.
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