I was involved in a thread on another forum where an experienced imager said that flats should be taken at same temperature as the lights. I disputed this and asked where he got the info from and this was his reply:
QuoteIts information based on first hand experience.
Example:
Cool the sensor to about 0deg, take a bunch of flats - then measure the maximum level of a few of the flats with Maxim DL.
Now, cool it to -15, do the same again.... you will notice a difference of up to 5000 - which is a lot. The reason being is that the hot pixels contribute towards the ADU reading, and therefore cooling the camera to match your lights will give a far more accurate reading.
Just wondered what our analytic members thought about this. I have never cooled flats.
Carole
It's complete nonsense unless the exposure time of your flats is so long that the dark current begins to be noticeable.
If so then you can take flat darks.
Mark
I was hoping you would say that Mark. They were talking about the Atik383L which has to have at least 3secs to avoid shutter shadow, but I would not have said that was particularly long.
Carole