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Message: <blockquote data-quote="elkcub" data-source="post: 3627702" data-attributes="member: 14473">Hi Lars,This discussion and the diagram on post #33, prompted me to reexamine my superb Linet Imperial 8x40 Fieldmaster.  It was made by Hiyoshi Kogaku in the early 1980s and has a real field of 12 deg., or an apparent field of 96 deg.  That's 96 deg. for each eye!!  I mention this because when the instrument is set to my IPD (165 mm.) there is no way that the two fields can overlap completely.  This is evident by the oval shape of the combined field-stops, and that the horizontal edges provide only monocular images.  I would estimate that the combined, binocular, field-of-view is approximately 96+25 = 121 deg., with a central overlap area of 70 deg.  (Unfortunately, the eye relief is very short (~10-12 mm) so viewing with spectacles is out of the question.)I'd have to ask Omar if this can be equalled or exceeded with his innovation.  A related question is whether or not this extreme FOV is even beneficial for birding or astronomy?  I guess there might be an advantage for detecting peripheral motion. As you say, without a working specimen this involves a bit more imagination than I can rely on. Ed</blockquote>