Quote:
Originally Posted by cometcatcher
.... Reflectors have free lunch, oh wait they have coma.
Looks like every system has a catch somewhere.
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Actually coma is easily managed and at low cost. Imaging with a f/5 reflector it is not an issue with a Baader MPCC stuck on the front of your camera. It is true that short f number reflectors become more problematic but really do you need a f3.9 with collimation and coma issues which only gain you slightly shorter subs?
I have tried to image with my iStar 127mm f/12 acrho refractor, which has far less of a CA problem than short ones. But honestly, a reflector is much easier with shorter exposures, and true colour rendition. You can also manage diffraction spikes by going to a curved spiders of they bother you. Frankly diffraction spikes don't bother me.
The comments above relate to DSO imaging, for high magnification planetary I would prefer a good ED APO refractor for improved contrast - despite the longer exposure required at higher f numbers.