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Message: <blockquote data-quote="ronh" data-source="post: 1751032" data-attributes="member: 55514">Here's my one-dimensional techie view of the difference.The 3-D effect looks the same as to the eyes, as viewed in a roof binocular having objectives the same separation as the eyes. This is easy to understand. If you are brought 8x closer, by walking or by magnification, and your viewers, be they eyes or bino lenses, are a natural eye spacing apart, the same convergence of the eyes is required. A Porro, with its wider spacing, artificially exaggerates the 3D effect.But there is something about any magnified view that is badly screwed up. Relative distances appear compressed, compared to how it would look if you just walked over 8x closer. You see this all the time in photos taken through strong telephoto lenses--this altered perspective is often referred to as "flattened".I think Porros might work to beat the flattening, with their exaggerated 3-D. They make it easier to pick things out, by giving back some distance separating power that the flattening takes away. These two unnatural things sort of compensate, to give a view that seems actually more natural than in a roof, to many peopleAs an aside, one of our members described to me his rather unique objection to the Porro. He spends a lot of time in very close cover, and often can only get a view with one eye, through a small opening in the foliage. The offset of the Porro line of sight from the eye means you have to move around to find that opening with a Porro, but with a straight-through roof, you just put it up to your eyes, and there it is.Ron</blockquote>

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