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Message: <blockquote data-quote="Kevin Purcell" data-source="post: 1286841" data-attributes="member: 68323">In fact re-reading the report and thread I see the results actually agree with my and eirikis observations. He puts and upper limit for handheld at x10 or perhaps x12 based on those measurements and says that x8 and less don't quite maximize the available resolution. I think this point gets overblown by "defenders" of lower magnifications (of which I'm one). Some of this is historical given the shifts in fashion in magnification over the years (x7 in the 60s and 70s, moving to x10 in late 70s and 80s then back to x8 or x7 in the 1990s and the resurgence of x6 and x7). Of course x8 is still the most sold. It's a good compromise.That said I was trying to get over the same ideas as Cesar but forgot DOF which is one of the reasons I love the x6 Yosemite - it has one largest DOF of all my bins.There's a lot more to birding than optics and those trade offs impact the optics that we choose. Depending upon habitat and personal style one can make good use of x6 to x10 bins. In fact that makes SwitchViews seem like an even better idea. My recent experience carrying a x6 and x10 pointed in that direction too.Another issue with higher magnification is weight and that's linked (indirectly) to exit pupil. A larger exit pupil makes the bin more "relaxed" and less "fiddley" but to get that at higher magnifications you need a larger objective (more glass, more tube) and bigger prisms (more glass). I find I like a 4mm exit pupil as a minimum and 5mm exit pupil gives room for error at twilight (even though my eye is stopped down most of the time). So that gives these potential configurations. 6x24 or a 7x28 or a 8x32 or 10x40. Of course the latter one weights more by something like the cube of the increase in dimension for the same "shape" of prisms and lenses. For the 125% increase from 32 to 40mm that would almost double the weight. In real binoculars the increase is less than this simple model indicates but it's not trivial (especially after 8 hours outside!).The military likes these lower magnification configurations but curiously they're difficult to find for civilians in center focus especially 6x24 or a 7x28.</blockquote>

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