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I am having a difficult time merging the two views into one image. I get two overlapping circular fields but not a double image. Not comfortable. I suspect this has more to do with the very small exit pupil than collimation


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This has more to do with close focus than anything else and really has nothing to do with small exit pupil or collimation. Typical 20x binoculars, regardless of what is posted as close focus, have a real closest usable focus of about 75 ft. (20m). They will show the field circles of the barrels will not completely overlap at least out to 200 feet (60m). This is common to most binoculars, and especially prominent in higher powerd binocs. Typical low powered binoculars that have a close focus of 15-20 feet will show generally only 75% to 85% of the barrel views is overlapped at 20 feet. Roofs do much better than porros in this respect, with roofs generally showing 85% to 90% of the barrel views overlapped at 20 feet.

FWIW, I checked the edge of field in the barrels of this 20x60 and it matches perfectly when used on night sky at infinity.

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As a follow up to these comments, I checked the close focus field of view overlap in the Pentax 20x60. First of all the close focus measured 27 feet. So at a distance of about 30 feet I measured barrel view overlap. The total width of view at 30ft is 13 inches across. Only 10 inches is seen overlapped in both barrels. Therefore, similar to many other binoculars I've checked, close focus overlap is about 80% of the FOV.

As I mentioned before, I checked the edge of field lap in the barrels of this 20x60 focused when used on night sky at infinity and it matches perfectly, fully 100% overlapped.

edz

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