Now that I may have you interested, this is an UNCOOLED shot using the COOL version of ZWO's ASI178MM. This is a 6MP camera with tiny 2.4um pixels. I wasn't using cooling because I seemed to be having problems with dew formation on the sensor when I had the temperature regulation turned on, so these were taken with mother nature's own cooling system, a fairly brisk night (at least in southern California, mid-30s). The sensor temperature was reported as being 47F.
Also, this is just 64 seconds of exposure for each channel (4s x 16 subs) with calibration using 100 DF and bias frames. Capture scope was a Tele Vue NP127is with a 0.8X reducer (e.f.l. 528mm at f/4.2). Normally I wouldn't use the reducer or such a short focal length for an object like the Eskimo Nebula, but I wanted to make certain that I could get something usable/recognizable on the first night out and I had some technical problems with the object I started with, which was M78 (that's when I noticed what seemed like dew on the sensor).
I measured the median FWHM on the final RGB composite and it turned out to be 1.9 arc seconds (just about 2 pixels). The median eccentricity was 0.45 which is kind of mediocre and while the small stars look fine there does appear to be some issues with the shape of the brighter/larger stars. There was no guiding used with the 4s subs (lucky imaging techniques). In total, I have 500 subs for each channel which will take some time to process and make fit for presentation but I thought I'd throw this quick look out for review since I don't think I've seen many images taken with this camera (or actually, none at all).
In any case, here is what just over 3 minutes of integration time looks like on the Eskimo Nebula when using the ASI178MM. This is a crop (1600 x 1200) from the center of the image, but it's shown at the full pixel scale (0.94 arc seconds per pixel). Fairly quick and straightforward processing in PixInsight and Photoshop CC2015.
Edited by james7ca, 10 January 2016 - 07:37 AM.