The two images are of USAF 1951 taken from approximately 30 feet, indoors, with the chart 16 cm wide (i.e., horizontally, measured from the vertical border lines visible on the chart. I know at 300mm I should really be 67 feet away, but my living room isn't that big.
One chart is VR on, AF single point, hand held. The other chart is VR off, MF, and resting on the back of an arm chair, so not hand held, but still pressing the shutter myself.
Both are ISO 1600, f5.6, 300mm f/l in both, but I screwed up on shutter speed, it is 1/320s in the MF chart but 1/500s in AF hand held; hopefully that won't prevent concluding whether the camera/lens is focusing properly. Both are JPEG fine, straight from the camera. no processing.
What i see is the smallest numbers and narrowest lines are borderline resolvable. They look a bit wider than the width of a human hair to me, so that would mean I am just short of being able to clearly resolve a single human hair, at 300 mm, indoors, from 30 feet.
I don't know if that level of resolution is acceptable or not for this gear, but it does explain why, when taking shots of monkeys from 50-80 feet, that i don't seem to get that extreme sharpness and single hair resolution that i see in some of the stunning pictures I have seen online, including from posters on this thread (but which may be taken in better lighting and closer, i don't know).
I have done some elementary maths, see below, which confirms your supposition is correct, you won't be able to resolve single hairs taken from 60-80 feet. Photos showing that level of detail are usually taken from much closer.
Nevertheless, I think part of the issue is motion blur in the hand-held photo; there is still a bit in the non-hand held version too. Notice how the vertical bars are clearer than the horizontal bars when looking at 100%, especially in the smallest ones in the middle, 5, and 6. The lens is moving vertically at the time of the photo being taken.
Are you able to do the same test with the camera on a tripod, using delayed shutter?
Resolving Human Hair. (Monkeys may have thicker hair!)
Europeans consider hair with a diameter of 0.04 to 0.06 mm as thin, hair with a diameter between 0.06 and 0.08 mm as normal, and hair with a diameter between 0.08 and
0.1 mm as thick. By comparison with European hair, Asian hair is significantly thicker. The average diameter of Asian hair is 0.08 to 0.12 mm.
Ref:
https://www.google.co.uk/webhp?sour...1&espv=2&ie=UTF-8#q=width of human hair in mm
Assume a distance of 80 feet, or roughly 25m. If the monkeys hairs are 0.1mm thick, then a to resolve them needs 0.2mm (for a line pair), so 5 line pairs per mm at the subject.
At the sensor, with 300mm lens the image will need to resolve 5 * 25/0.3 = 413 line pairs per mm.
Per tests done by Optyczne, the Nikon V3 resolves around 95 line pairs per mm with the 18.5mm f/1.8 set to f/5.6.
Ref:
http://www.optyczne.pl/282.4-Test_aparatu-Nikon_1_V3_Rozdzielczość.html
So assuming the 70-300 can also resolve 95 lp/mm at f/5.6, to resolve individual hairs you would need to be about four times closer, about six meters or 20 feet.
I'm open to correction on these calculations!
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DaveR