A few more interesting telescope observations


An article writes

It is said that as one gets older one’s sensitivity to the extremes of the visual spectrum gets less so more elderly observers may not find the resulting false colour a problem.  One reason being that the yellowing of the eye’s lens tends to filter out the blue part of the spectrum.  I suspect that this is true and was somewhat amazed recently when I turned my 80mm, f/5, achromat onto the Moon and could not really see any false colour near the limb.

This may well be true. After cataract surgery I am very sensitive to blue fringe now where before I was not. Even in well corrected scopes if the eyepiece has any blue fringe I'll find it.

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