This is also the case for mine. Mean ADU of one frame in kstars viewer is 215 ADU

The master bias is showing a mean of 3.24e-03 in PixInsight which after some math equal to 212 ADU


The most important is not the mean of the bias but the average deviation. In my case the bias is 0.32% of the max ADU with an average deviation of 0.006%
A big average means that you crop the full range ADU of your camera but if the deviation is near to zero, you can live without the use of the bias in you processing.

Unfortunately, in the case of Atik 314E we need both of them. I don't know what is the delta temperature reached by the cooler but what I'm sure is that night temperature in winter and summer is not the same in France. I have to use at least 2 set of master bias. I think I will perform in the near futur some experiment in my fridge and my freezer just to know the effect on the mean value of the bias.

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