Hi Humayun
Yep - I take plenty of darks (at least two) every time i change camera timing or ISO settings - as well as a couple for every shift of 10 degrees or so in air temp. I them group shots by these darks and stack them accordingly. I guess I'd still like to know how long chip heat typically tales to dissipate, but 10 secs should see most of it gone I'd presume. It's kinda like a turbocharger, where a 15-second idle at the end of a hard run sees the turbo casing drop several hundred degrees in no time. It then takes ages to actually cool....