AJSJones Offline Upload & Sell: Off
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jcolwell wrote:
I have seen it (relationship between binocs 'power' and lens focal length), but I don't remember the details, and I'm all googled-out, for today.
The best way to figure it out would probably be to match AOV, which is 8.2 deg (diagonal) for the 300mm lens on FF.
There is a slightly different way of looking at it. I have a Kenko Lens2Scope converter that essentially is a telescope eyepiece that you can attach to a camera lens. The Kenko that I have is a "10x" converter, which means that the AOV with the converter on my Tamron SP 300/5.6 lens, and this 'scope' up to my eye, is the same as a 3000mm lens on FF. IOW, I can scan the distance with this small 'scope' and get much higher detail than I would get from my 500mm lens on a FF camera, or even on a 1.6x cropper.
Other converters provide different magnification. For example, the old Pentax K-mount monocular converter was 5x.
Kenko Lens2Scope https://www.bhphotovideo.com/c/product/857279-REG/Kenko_K_LS10_CESB_LENS2SCOPE_for_CANON_EF_S.html
Pentax Monocular converter http://www.bdimitrov.de/kmp/lenses/adapters/monocular.jpg
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I did not know of such things - I might be inclined to add one to my kit
I've always used a rough measure that ~50mm is 1x, approximating the unaided view (so objects look neither magnified nor reduced) and divided that into my lens mm, so a 400mm is roughly 8x. Not sure how kosher this is, however.
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