I would like to get some advice and best practices concerning camera temperature and dark frames. Regarding camera temperature, I read somewhere or maybe someone told me that the STXL 16200 temperature will not go below -35 Deg C because there is little or no improvement to be gained by going lower than - 35 Deg. Is this correct ? Regarding the camera temperature, I can get to -35 Deg C without supplemental water cooling as long as the ambient temperature is below about 15 Deg C. When the ambient temperature is in the range of 15 to 22 Deg C I can get to -33 Deg C before the camera fan kicks into the high speed mode (which I try to avoid). Above 22 Deg C I can only get down to -32 Deg C. Is there any noticeable performance improvement between -32 and -35 Deg C ? Regarding dark frames - I typically keep a "library" of dark frames at various temperatures and exposure lengths to use for calibrating my images. Is there a recommended frequency at which these dark frames should be updated ?