Test of Canon 200mm F/2.8 Telephoto with QHY183c Camera

M45, The Pleiades. 56×30 sec, QHY183c, Gain 20, Offset 31, -15C, Canon 200mm F/2.8.
The North American Nebula. 167×30 sec, QHY183c, Gain 2, Offset 31, -15C, Canon 200mm F/2.8.
The Horse Head Nebula Region. 8×120 sec, QHY183c, UHC Filter, Gain 20, Offset 31, -23C, Canon 200mm F/2.8.

I bought the adapters needed to mate my new QHY183c camera to my Canon lenses.   I tried it out with the 200mm F/2.8 telephoto.   No way to control the F-stop diaphragm, since it needs a Canon camera to do that, so I had to shoot with it wide open.  BTW, this was from the light polluted metro area I’ve been shooting from lately.

Since this is one of the cheaper lines of Canon lenses, it suffers from optical imperfections like astigmatism.   That makes the red focus to a line up and down and blue and green focus to a line left to right.   It really messes up the star shapes and there is no way to fix it except to stop the lens down to F/3.5 or higher.   Oh, well…

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