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Message: <blockquote data-quote="edz" data-source="post: 1262363" data-attributes="member: 44073">1st answer yes.  Actually I just tested that today in three different optics.  You hit an upper limit of power, and then there is no gain.  In some instances the view gets worse.  In my 80mm scope I saw exactly the same resolution limit at four powers from 125x to 175x.  In several binoculars I could see no more resolution at 70x and in fact it in one it got worse at 80x.2nd, perhaps yes.  generally a lower acuity can see the same object when a higher power is applied.3rd, yes, but only in that scenario.  if they both use one of the same binocular and get very different results for power to reach the limit, then that would clearly be showing the difference in acuity between the two observers.  But, that is just one scenario.  Suppose there is only one observer and we follow thru #1.  And let's also suppose the observer has two binoculars, same size, but different quality.  At same power limit they show very different res results.  That's a completely different scenario than anything you mentioned, and it's not measuring acuity.  Or suppose two observers have the same acuity and compare two different quality binoculars and get different results.  What then?  Certainly not acuity.a fourth scenario.  ONE observer uses two different brands binoculars, but both same size, and both used at numerous powers.  For sake of discussion they both do very well, they both see 3".  But the first one can see 3" at both 60x and 65x and shows no further increase.  the second one does not see 3" until you reach 70x.  beyond 70x, there is no further increase and it is fuzzy.  This is not a test of acuity.  The first binocular reaches the resolution limit at a lower power, has a lower apparent res and is better. these examples provided specifically to show in these scenarios, beyond your example, it is not testing acuity.edz</blockquote>

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