I have been trying to find equivalents for the old US (Uniform System) f-stops on my Protar.
Here is what they look like:
P1010932-2 by Ari4000, on Flickr
Is there a method to determine the equivalent in modern f-stops?
For example, to my eye, f256 on the lens makes a similar-size aperture as f45 on a modern lens.
I have seen a few charts here and there, but they are quite old and make little sense to me.
Any help is appreciated.
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