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Old 14-02-2012, 12:56 PM
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Dave2042 (Dave)
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Quote:
Originally Posted by clive milne View Post
Dave, all else being equal the TV Plossl should have very slightly better axial contrast than you will see in Nagler of the same focal length. I don't know if the difference will be large enough to notice though. This is simply a function of the number of air-glass transitions. There may also be a secondary effect of light scatter in your eye. The wider the field of view, the more light you will get entering your eye, it obviously follows that there will be a slight reduction in overall contrast. If this is to any meaningful extent, I could not say.

Where the Nagler hoses the Plossl is in it's field correction, the faster the primary objective, the more noticeable this will be.

I think it is also worth drawing the distinction between the metric by which we evaluate an eyepiece and the observing experience itself. Point being, I personally am prepared to accept the faults inherent in the Naglers and Ethos designs because perceptually, I find the interference of a field stop a greater offence to my sense of reality immersion than the 2% (or whatever) loss in contrast that comes with the territory.

This is a personal choice. ymmv.
Interesting. Thanks for the comment.
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