How cold should set-point cooling be?

[x6gas]

Hi all,

I'm new to the world of purpose built astro CCD cameras and I have a basic question about set-point cooling.

My camera will, apparently, cool to 40*C below ambiant, so what are the parameters to take into account with respect to the set-point cooling?

I know that the lower the temperature of the sensor, the lower the noise so is it a case of just cranking it down as far as it will go? I guess you need some contingency in case the temperature rises during a session to ensure that there is enough leeway to ensure that all of the subs are taken at the same temperature but is there anything else to be aware of?

Apologies for the noob question and thanks in advance, Ian

[Earl]

-20 is a common value, it all depends on your average ambient though.

It would be interesting to know how much noise reduction there is for say -30 vs -20

the last few night im struggling to get to -20 so have gone for -15, I really should make some darks for it also, but not to fussed at this exact moment, ill wait till some cloudy nights for that.