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Message: <blockquote data-quote="looksharp65" data-source="post: 1934939" data-attributes="member: 83771">This mystery has been keeping my mind busy every free minute. Well, I have been really busy at work, but still...In accordance with my above-mentioned post, the sharpness or resolution is crucial for obtaining the 3D-effect. It is not a secret that 42's have better resolution than 32's, since they simply grasp a wider light cone.Furthermore, they may have a wider sweet spot as measured in degrees/absolute numbers. So when the sharpness of the image starts to deteriorate towards ..say 65% of the field, the sharpness is not anymore really sufficient to contribute to the 3D-effect. (remember: Image separation - Convergence -Sharpness).In contrast to my speculation in the earlier post, I think that the medial parts of the front lenses (located towards the physical center of the binocular) may have greater contribution to the 3D-effect than the lateral/outer parts have.The reason would be that in a mid-size or compact roof, the distance between the inner edges of the barrels is greater than in a full-sizer. The result is that the "blind angle" extends further away from the binoculars."Blind angle" should be translated not as unseen, but where the two barrels don't share a joint/stereoscopic view, but rather monocular. The reasoning that resolution would also have impact on the 3D, strengthens this idea about a "dead angle" of compact roof bins, and "bad angle" of midsizers.But this is not so hard to overcome - all it takes is to be active in adjusting the IPD, not as much as with a porro, but more with a midsizer than a full-sizer.Unfortunately, the 4 mm exit pupils of 8x32's don't allow too extensive adjustments before other unwanted things like blackouts occur.At last, there is some probability that the better exit pupil illumination of an 8x42 as compared to an 8x32 allows the user's pupils to constrict just a little, but enough to increase the contrast and depth of field in the retinal image.Does it all make sense?</blockquote>

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