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Message: <blockquote data-quote="henry link" data-source="post: 412066" data-attributes="member: 6806">Bawko and elk,I don't have much time for a reply as I am about to leave for a week's vacation with no computer. Bawko, your eyesight actually looks to be quite good from your results, better than 20/20, but you would need to have better than human eyesight to see detail as small as 14", which is the probable 2" actual resolution of your Leica 7X42 multiplied by its magnification. The 7" you reported for that binocular multiplied by 7x is 49" which is very good eyesight acuity but almost certainly far below the actual resolution of the binocular. The astigmatism I was refering to would be in the binoculars, not your eyes. If the axis of the astigmatism happens to be aligned or nearly aligned vertically it will cause a loss of resolution in the horizontal bars but have much less effect on the vertical bars. A star test would indicate if this is the cause. I suppose I think "resolution" is a bit of a red herring in binoculars. It's certainly true that some binoculars look "sharper" than others, but the magnification is so low that any good quality binocular is not really being pushed to its resolution limit when you simply look through it. There may be problems of many sorts in the image, but in my experience it takes a very bad or very defective binocular for its actual resolution to be worse than eyesight acuity. I may be wrong but I think if these experiments are done repeatedly the averaged result with the good binoculars will wind up being the experimenter's eyesight acuity divided by the binocular's magnification. In other words I think it is essentially an eye test. Henry</blockquote>

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