Hello,
"cool" was the right word for this night. At a modest cooling down to -15°C the sensor was some °C less than ambiant temperature.
In the beginning I've purchased the ASI178MM to image the Moon, but I've picked the cooled model to explore deep-sky too with the same camera.
No flat, no dark, no offset but still very decent raw images (as long as no light leaks through the filter wheel).
I noticed a field rotation (left of image) due to improper polar alignment, resulting in star trails within 20-s exposures.
With such tiny photosites, the camera is very demanding but my results are progressively getting better.
I've tried various settings of gain, binning and exposure. Binning x1 results in by far better raw frames while the camera is sensitive enough to keep relatively short exposures, at the exception of Halpha which typically requires 120 seconds (gain was 250-350).
More subs would have resulted in a better final image but frost was forming on the optical tube and the laptop, in addition to light scattering by air humidity, then I gave up before lethal freezing.
This is a modest 150-mm (6-in) F/4 Newtonian with a coma corrector.
Registration with DeepSkyStacker, very soft processing with FitsWork.
Nicolas
