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Message: <blockquote data-quote="jcbouget" data-source="post: 1536610" data-attributes="member: 17837">During the past few days, I spent a lot of time in testing several binoculars. Of course, one of my goal was looking for parameters that could influence depth of field.I have two specimens of the Meade 10x50, the famous “Lidl” binocular <img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="smilie smilie--sprite smilie--sprite2" alt=";)" title="Wink    ;)" loading="lazy" data-shortname=";)" />.I carefully star tested each barrel at 50x thanks to a 5x10 monocular in order to rank the objectives. Then I screwed the two best objectives in one binocular, and the two worst in the other, and I made a careful alignment of each binocular for my IPD. As a result, one binocular is indeed slightly sharper than the other, but the difference is small.I compared extensively the binoculars under various conditions, at various distances, and with various methods. I couldn’t see any significant difference in depth of field between the two. I hoped that I could prove that optical aberrations reduce the perceived depth of field. Unfortunately, I had only the feeling that the best binocular had sometimes a slightly better DOF than the other. In fact my tests are not conclusive. Probably the worst binocular is good enough to allow my eyes to work normally.I also tested the influence of collimation. I have deliberately altered the alignment of the worst binocular in several ways : about 0.75° of horizontal divergence, about 1.25° of horizontal convergence, and a slight vertical divergence. Again in each case the perceived depth of field was unchanged. I find this result interesting because it eliminates the hypothesis I made about collimation. Jean-Charles</blockquote>

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