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Message: <blockquote data-quote="tenex" data-source="post: 3652800" data-attributes="member: 135233">The effect is pretty obvious in this 8x25 VP.  When I focus on something in the center I can move the bino around and that target is still acceptably sharp at the top or sides of the field, but not at the bottom.  If I try to focus on what's near the bottom of the field it seems difficult to get it perfectly sharp at any setting.  Results are the same with the bino reversed.The thing is I've never noticed this using other binos.  I don't see it at all, or perhaps just barely, in the 10x32 UVHD+ I have on hand now to compare.  If it's my own astigmatism, can one bino show this effect more prominently than another, and why?</blockquote>