X100 lens performance oddity
With absolutely nothing better to do, I shot a number of frames out of my back door (towards a fence with trees directly behind) starting at F2, until F11, to see how the lens performed and whether there were any glaring concerns where diffraction hit hard etc.
It was odd to note that the edges got sharper from F2 to 2.8, but actually got worse at F4-5.6 (from f2.8) then jumped up in performance again at F8, 11 etc. This is most peculiar. The difference is not huge, but plainly visible.
from f2-2.8 there is an obvious leap in contrast as well, but by f4 it does not seem to increase much. Resolution on centre remains unchanged from F2.8 until about f8, after which diffration sets in.
How on earth can a lens get sharper on the edge one stop down, get worse for next two f stops, then leap up again at f8. I have repeated this numerous times and it is plain as day and not my imagination!
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