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Old 10-05-2015, 05:52 AM
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gregbradley
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Join Date: Feb 2006
Location: Sydney
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Quote:
Originally Posted by Slawomir View Post
I am using a reducer/flattener, and CCD inspector is showing curvature in the corners with the CCD being about 4mm away from the optimal distance. I can live with that, but at the same time would be nice to have perfect stars to the corners.

Yes, one day I would like to be able to get a camera with a larger CCD, and 16070 definitely looks interesting. Also maybe in a few years we will be able to choose between CCD and CMOS cameras?
Oh I see. I don't think there is such a thing as a reducer/flattener. That's some false marketing hype. Its one or the other. Reducers do tend to elongate the stars in the corners if not at the right spacing and have a limited corrected field whereas flatteners are usually fairly tolerant.

Its like William Optics marketing their scopes as fluorite which is false. They use FPL53 glass which has a lot of fluorite in it yet the public understand that marketing as the lens is made from CaF2 which it is not. CaF2 has less scatter and a better refractive index.

Greg.
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