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Old 26-01-2015, 08:06 PM
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gregbradley
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Join Date: Feb 2006
Location: Sydney
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Quote:
Originally Posted by dp297 View Post
Dear Greg,

I appreciate your analytical response very much.
I am surprised that u think that Pentax is a better lens than Nikon 180ED.
I will most certainly look into that.
To tell u the truth I have only used Nikon with narrowband and it was perfect but not with LRGB..so I dont have direct experience other than what I have read on the web.
I use Lightroom to defringe the stars that have blue halos from the chromatic aberration of the 180mm. It works well. That was at F4. Perhaps F5.6 it may clean up more. But the Pentax 67 165 F2.8 is sharp to the corners of a 16803 chip wide open and nice and sharp. The 75m is a very sharp lens and very little aberrations (a few more than the 165 but a wider field of view).

Greg.
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