Quote:
Originally Posted by Amaranthus
How do you find the SW120 f5 as an overall performer, Kevin? I'm thinking of getting one for some rich-field visual work, and maybe mounting it properly for some astrophotography...
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Barry, for visual it's absolutely brilliant. There's CA on bright objects but for DSO's it's great. Stars are pin point. Not sure how it is on planets as I haven't tried. I would suspect not so good.
For photography... well it's hard to tame. The CA is bad. For dim star fields and nebula you can get away with it. But in a bright star field like M42 and one shot colour, it's pretty horrid. See attachment with no processing. With a nebula filter and post processing it cleans up a lot, but not completely.
It's awesome for comets, which I like to use it for both visual and photographic. I think I get away with it for comets because they are almost always faint and the star fields get blurred out by trailing as I track on the comet so the CA doesn't get a chance to "build".
Narrow band filter imaging should be okay also, but there is a focus shift between filters. I find the focuser okay for visual but a pain for photo work. When I get some $ to spare I want to upgrade it.
Here it is with a Mizar 68mm f8.8 guidescope on an HEQ5 pro. They are both 600mm focal length. The SW120 is also shooting through an Orion field flattener.
I'm after the F8.3 version of this scope if I can get one for a good price second hand. New they cost nearly as much as an ED scope. CA is always better at higher F ratios.