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Message: <blockquote data-quote="APSmith" data-source="post: 1312122" data-attributes="member: 52350">You must be kidding.  Where did you come up with 90-95%?  I think the "Zone" you're discussing must be something different from the "zone of critical sharpness" (Sweet Spot?) that I'm trying to describe.  Consider this excerpt from Herny Link's exceptional 2005 review of the SE and EII: I tried to get some idea of off axis sharpness by placing a measuring tape about 40’ from the binoculars and perpendicular to the line of sight. At that distance 60” on the tape spanned the full 60 degree apparent field of the 8x32 SE, so each inch on the tape would correspond to 1 degree of apparent field for any 8X binocular. I focused at 30” and using one eye tried to judge how far I could move my eye along the tape and still see something close to the best center sharpness, maybe 90%. This is of course pretty subjective. My focus accomodation varies so I don’t always get exactly the same result with the same binocular on different days, but I ‘ve found that the rankings tend to stay the same. On this particular day I found I could see something close to the best center sharpness across 34 degrees through the SE, 28 degrees through the EII and 24 degrees through the “good” side of the E. I also tried a Zeiss 8x42 FL to see how it compared. It was a close match to the EII at about 28 degrees.This is a far cry from 90%.  It's more like 32% (area) or 57% (radial) for the "winner" (the SE). This handy experiment of Henry's for evaluating off axis sharpness identifies the criteria in which I'm interested.  The range of his measurements matches reasonably with my general impression for "something close to the best center sharpness".  Is this not the same thing as "Sweet Spot"?APS</blockquote>

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