Quote:
Originally Posted by Anthony
Realistically, human 20:20 vision is a resolution of about 1"/100 yards, so 200-300 yards.
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A letter on the Snellen chart is five arcmin, and the single lines and spaces are 1 arcmin. A circle with radius 100 yards has circumference 1885'; one degree is about 5', and one minute then is 1". At 500 yards, you'd be able to see body parts that were 5" across, which is about the right order of magnitude for head, arms, or legs; since SM -6 corresponds to 7", it's roughly correct. You'd need to be significantly closer to recognize facial features, of course.