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1. Originally Posted by JBrunner
Far more of my negs are soft because I suck than because of diffraction. YMMV.
I think that sums up my negatives too!

Steve.

2. Ralph: do you not mean 4x as much (linear) resolution at f/8 than f/32? I understood that at the diffraction limit, the diameter of the Airy disc to the first null is d=2.44*wavelength*Fnumber. Therefore at f/32, the airy disc is 4x the diameter than at f/8.

3. Originally Posted by polyglot
Ralph: do you not mean 4x as much (linear) resolution at f/8 than f/32? I understood that at the diffraction limit, the diameter of the Airy disc to the first null is d=2.44*wavelength*Fnumber. Therefore at f/32, the airy disc is 4x the diameter than at f/8.
No, I said and meant 2x. I wasn't comparing theoretical diffraction limits (in which case you would be correct). I was comparing actual lens performance between these apertures as shown in my graph in post #5.

4. ah, fair enough.

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