When Summer Heat Defeats Imaging - ASI1600 Cs

[glend]

As in past years, I packed up the observatory gear a couple of weeks ago and brought everything back into the house. I tend to image hibernate over summer because of the crappy Seeing, and the high overnight temperatures that keep me from getting my 1600MM-C sensor to stay at -25C. All my Darks, Bias, etc library is shot at -25C, so i just wait for it to cool off again.
What's your strategy for heat management? I know Dunk has a higher temperature target setting, that lets him go longer during this season. Do you just shoot at a year round higher temperature target (say -15C); or run various Dark libraries to suit different seasons?

[Atmos]

This time of year I set it to -15°C. Even then on some nights it’ll be running at 80% when I start imaging but down to 30-40% by morning.

[billdan]

I've set my dark libraries at -15°C which I can achieve all year round.
This time of year at my place, its still 30°C at midnight so I couldn't go much lower than -15°C with the camera.

[barx1963]

My Atik camera with the Sony 694 chip is very clean. It still produces decent images if only running at -10C. I usually run at -20C but have a library of darks and bias files done at -10 just in case. The Atik can often produce pretty good images without any darks included in the preprocessing at -20. My other camera is an SBIG STT-8300 with the KAF 8300 chip and that is still pretty noisy at -35, so I never use that on warm nights.
As with all things it is the result that matters. If you need to run at a higher temp, but results are still acceptable, then that is a good result.

Malcolm

[Camelopardalis]

Yeah I use a standard cooling level of -10C, as up here in QLD I can attain that even on warm summer nights, like last night where at midnight it was still 25C and 80% humidity :lol:

The 1600 has no problem handling that though, and I'm not convinced that the increased thermal noise from going that much deeper is significant, given the number of subs I (would) like to chase... the 1600 is pretty low noise by any standard.

[Slawomir]

I don't use darks because with my camera there is about 1ADU of even dark current in a 15-minute exposure at -15C, and since there is insignificant improvement in bias below -15C, I always run my camera at that temperature, so the cooling never needs to work too hard.

[ZeroID]

Judging by the quality and performance I am getting out of my 1600mm-c at 0* I don't see the need to run at -25. I don't think it would be achieving very much more. In fact I haven't bothered with Darks yet. Some of my early experiments at ambient were still incredibly clean and free from hotspots or noise. Must be a lucky sensor. :thumbsup:

My aim is to standardise probably at -10* now I have most of the basics sorted out. Cooler runs at about 5-10% power and I'll build a darks library soon.