What is mFT FoV?

Started Jan 27, 2013 | Questions thread
gollywop
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Anders: some measurements
In reply to Anders W, Jan 31, 2013

Anders W wrote:

gollywop wrote:

Whoop, Anders, your link to the means for testing angle of view doesn't work. Can you try again?

thanks,

Don't know what went wrong with that. But I corrected the link by editing my previous post. It should work better know (at least it did when I tried) but here it is again just in case:

http://www.panohelp.com/lensfov.html

Well, Anders, it seems my hypothesis (and hope) was wrong. The nominal focal length appears to apply to the uncorrected, not the corrected, image. I did the measurements according to the link you give above. I did them twice, once fairly rough and ready and again much more carefully, but there's no substantive difference; they tell essentially the same story with the 12-35 at 12mm:

The corrected AoV is about 68.67° for an EFL of 26.35

The uncorrected AoV is abut 73.33° for an EFL of 24.23.

So, the 12-35 appears to be a 12mm lens only if you put up with the distortion. It is otherwise a 13 mm lens (at least after ACR does whatever it does -- which, I suppose, is effectively what the OOC jpeg would be also).

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gollywop

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