Domanski Does it mean the temperature sensor is faulty and has an offset of -8°C?
Well, you don't really know the true offset since the placement of components is different for different cameras.
Personally, not knowing the mechanism for the error, I would return the ASI294; there is no reason that as a customer, you should accept something that does not meet specifications, and have to make guesses when you should not need to.
How do you know that when you take dark frames at "-10ºC," that the sensor has the same temperature as light frames that are taken at "-10ºC" at a different time and environment.
The ASI294 dark frames already appears quite finicky as it is -- because of that, I never bought the cooled version of the ASI294, and just use an uncooled version of the 294 for more casual stuff, like an all-sky camera.
Chen
