[JohnG (John)]

Well, sorry, that is not my experience.

I have found that so long as you take your Darks, say 3-5 at the beginning of your run, 5-6 or so during the middle of your run and the rest at the end, combine them to make a Master Dark, they are good for any Lights taken around the same temp, I normally make Master Darks every 3-6 months, depending on the season.

Please feel free to correct me but a Master Dark is the combined average of the 20 or so Darks taken during an imaging run done as above, therefore you are covering a multitude of temps, starting from when the DSLR chip is cold to when it heats up over the period of the imaging run.

Every persons setup is different, every person mileage is different, this works fine for me when Lights are taken around a similar temp. You need to test your own setup and find out what works for you.

Just my opinion from a lot of experience.

Cheers