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Message: <blockquote data-quote="elkcub" data-source="post: 1744879" data-attributes="member: 14473">By "roof illusion" I assume you mean the observation that roof binoculars yield larger apparent images than Porros, but less stereopsis.  (It's not an illusion, as I mentioned; it's a perceptual experience.)There are two closely related tasks, "acquisition" and "identification."  The former has to do with capturing (i.e., becoming aware of) the presence of an object in 3-space, the latter with determining what it is.  The literature supports the notion that stereopsis declutters a complex visual environment and improves target acquisition.  The extreme comparison would be between a binocular (two different images) vs a biocular (two identical images).  It's my educated guess that incrementally improved stereopsis also improves target acquisition incrementally.  As for target identification, which necessarily follows acquisition, I don't know that stereopsis makes much difference.  (Note that I have avoided reference to apparent size differences for reasons stated earlier.  Apparent size is a transitory perceptual experience subject to rapid habituation.)  Down to particulars, the issue at hand with the Nikon vs Canon is: "I believed I was seeing more...because it appeared larger."  I can't argue with causal beliefs, my friend, just suggest there may be less evident factors to consider apart from apparent size.  In any case, the challenge is really for you or someone with that belief (i.e., experimental hypothesis) to prove that apparent size enhances target identification, rather than for skeptics to prove that it doesn't (i.e., prove the null hypothesis).  This may lend meaning to: "Don't believe anything you hear and only half of what you see."  <img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="smilie smilie--sprite smilie--sprite2" alt=";)" title="Wink    ;)" loading="lazy" data-shortname=";)" />Ed</blockquote>

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