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Message: <blockquote data-quote="OPTIC_NUT" data-source="post: 3170881" data-attributes="member: 121951">In doing measurements down past the eye's actual acuity(with a low-power monocular) I have noticed the following:That a resolution in the range of an apparent 15-30 arc-secondscorresponds with a perception of great 'sharpness' and, especially,a stronger 3D effect that lasts out past 100 yards.  I first noticedthe link with a pair of IF 7x35 Manons. I can't read font that low,but I can see a more precise line, it seems.That leads me to believe that you can actually extract a greaterprecision out of lines or curves than the normal 'dot-to-dot' seperationfigure would suggest.  It makes some sense, given how simple themathematical  job is refining the edge in image processing (along-axis-filtering or with least squares).  One consequence  is thatthe alignment within each barrel is important. Another is that the focusermust be extremely stable left/right to get this last bit of apparent 'sharpness'.Off the shelf or in the shop, I can pick up various great binoculars but thenone pair is suddenly 'all there' for the view.  That might be it....the lastbit of alignment.  Very smooth focusers are key too. Otherwise, you can'tfind the perfect spot.</blockquote>