Quote:
Originally Posted by Peter Ward
QHY are temperature regulated. Not to the same precision as SBIG (who have a patent on keeping the chamber temp to 1/100th of a degree or so) or FLI.
i've found it is a little tricky to estimate just what delta t you can get with a QHY, as the power required seems very nonlinear. But as the chips are thermally "quiet", a set point of -10 is more than adequate.
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Except for the fact that some owners are reporting banding at warmer temps and it becomes far less when cooled.
High cooling also reduces lines in CCDs so banding it would seem may disappear all the way with stronger cooling.
I also wonder about how stable their temperature regulation is. It could affect darks but then again it may be unnecessary to use darks like it is with the Sony ICX694 and other sensors.
Powerful, stable cooling may be less important with these sensors but I can see it would still be nice to have too much cooling rather than not enough.
Perhaps this sensor will come out within a year from other camera makers like SBIG, FLI, Moravian.
Perhaps its not even an issue but its a bit early to tell and perhaps it affects one brand more than the other.
On Cloudy Nights I see posters talking about using -5C. But that's in their Northern Hemisphere winter. Try getting that with 30-35C delta in an Aussie summer night. You may end up at +5C which may not be anywhere near enough.
Greg.