Thread: SBIG or QHY9
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Old 12-12-2009, 10:35 PM
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AlexN
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Location: Caboolture, Australia
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Quote:
Originally Posted by Tandum View Post
People have been telling me the sbig has 2 stage cooling but the web site says single stage cooling. How can it achieve -40delta cooling with a single stage tec? I believe the colder these KAF chips are the better the perform.

I missed this post earlier..

They are a single stage TEC as the website says. -40°c Δ is not difficult to achieve with a single stage TEC depending on the power consumption of the element. A sufficiently power hungry single stage TEC could achieve almost any ΔT. However I think manufacturers of astro CCD's have to stick with lower power TECs in order to reduce both electrical noise, and power consumption of the camera.. Sure it would be nice to achieve -60°C Δ T, but if it required 12v 10A to do it you probably wouldnt be so impressed..

Dark frames I've seen from a few different KAF8300 based cameras seem to indicate that anything below -10°c gives very acceptable results, and anything much lower than -20°c seems to make little difference.. I've seen dark frames from the ML8300, QHY9, Apogee U8300M and QSI583 at varying temps from 0°c to -30°c...
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