I’m still getting used to my first cooled astro-cam (ASI2600MC Pro) and am wondering what kind of sensor temperatures I should expect to be able to maintain here in Oklahoma. I was imaging the other night where the temps were probably in the upper 70s (25C or so) and I had the cooler set to -10C, but it wasn’t able to get down below about -8C. I think that’s probably pretty normal, but wanted to see if anyone has a different experience with cooling in the summer. Thanks for any input!
I am also getting used to a ASI2600MC Pro. I have not been able to use it yet this summer. An online search found that it should cool 35 degrees Celsius below ambient temperature. For an 80F ambient temp (almost 27C) it looks like it should be able to get to -10C. I am interested what real life users have to say. Thanks for posting.
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I’ll be interested to see what you’re getting once you get some data with your 2600MC Pro. Next time I’m out I’ll pay more attention to ambient temps so I’ll know what my real-world deltas look like, and I’ll try to remember to post them here.
I’m in the process of taking some darks at -8C and -5C in anticipation of warmer nights. May as well be prepared in case I can’t hit the lower temps.
I have a ZWO ASI6200MM Pro which is the same camera with a larger mono sensor. After working for many years with CCD sensor cameras which are very noisy and can greatly benefit from sensor cooling, the CMOS sensors have a very low noise (dark current). While dark current does decrease with cooling it is almost unnecessary. I prefer to be somewhat conservative in setting the cooling temperature so I can create a set of Dark Masters that I can use for several sessions. Therefore, in the summer I tend to use either -5C or even 0C depending on the temperature during the start of the evening.
To supply you with some background, your ASI2600 has a dark current of only 0.0022 electrons per second per pixel (e/s/p) at 0C. For a 300-second exposure, this is only 0.7 e of dark current noise. This is less than the readout noise which is almost negligible. Cooling was necessary for CCD sensors because of the higher dark current. For example, the KAF-6303 CCD sensor has a dark current of around 25 e/s/p. Reducing the temperature every 6C cuts the dark current by one-half. So by cooling the sensor to -30C, this reduces the dark current to around 1 e/s/p which while significant, is still considerable higher than the ASI2600 CMOS sensor cooled to 0C.
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Thanks Rod, that’s really good info to know. Given those numbers I think I’ll just stick with -5C or 0C for warm summer nights and not run the cooler at 100% chasing an unobtainable temp. Really appreciate the detailed input!