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Message: <blockquote data-quote="ronh" data-source="post: 1355767" data-attributes="member: 55514">Give up.Here is a classic case where the messy zoo of binoculars, eyes, and usages will never conform to scientific reason. If you took careful measurements of depth of field using impartial instruments in a controlled setting, the results would not conform to people's subjective impressions,  so what good are they? The "confusers" of true field depth, including stereo effect, field curvature, and sweet spot size, cannot just be thrown out. What it "looks like", not what it "is", is really what's important here!Depth of focus, in the case of diffraction-limited astronomical telescopes focused at infinity, has been ably analyzed by Roger Gordon and Chris Lord.<a href="http://www.brayebrookobservatory.org/BrayObsWebSite/HOMEPAGE/forum/depthoffocus.pdf" target="_blank">http://www.brayebrookobservatory.org/BrayObsWebSite/HOMEPAGE/forum/depthoffocus.pdf</a>It might seem tempting to use geometrical optics to make the translation of their results from image space to object space and call it quits. But related to binoculars, the concept is too complicated, subjective, and illusory to have any hope of success with such a sensible approach. Personally, I appreciate people's personal depth of field impressions, and measurements, too. They all add to the rich pastiche which is depth of field. I just grow weary of the endless truth-seeking. My military style Fujinon 7x50 has TERRIFIC depth of field! Must be the magnification or something like that? If I focus my 16x70 at infinity, everything over a mile away looks pretty sharp too, as far as I can tell, but as a daytime binocular it sucks in the first place so I'm not real sure, but still not bad, huh? If an astronomical object comes closer than a mile, I have worse problems than my binocular's depth of field. But my Leica 8x42, woah, it takes the cake. It has a "Focus Knob", so who cares---it doesn't NEED depth of field! I hope I have offended nobody, or at least everybody equally,Ron</blockquote>

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