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p.2 #7 · Canon 35 L 1.4 sharpness | |
I don't mean to be confrontational, but I find claims for sharpness on fast lenses to be questionable.
I have seen "decent" center sharpness wide open, but it is with reduced contrast/resolution, and most importantly, the sharp image areas are a small fraction of the frame, in the center. That is no way to determine sharpness in my book.
I know many photographers love the look of OOF areas showing extremes of bokeh. Anything even moderately sharp as a small area in these nebulous areas will appear sharper than it actually is, than if you were to compare it within larger areas of focus. That's fine for effect (or gimmick), but not really a proof of sharpness. (love the lips photo, BTW!) It can be, likely is, that the lens aberrations and lack of focus in corners actually adds to the desired "look", even though the lens isn't as sharp as it seems.
If you take a look at the photo above of the dog, the nose and some fur is nice and sharp, but for the overall frame, it is a small percentage. And notice the magenta/green in the OOF areas in the window frame/shutters indicating the optical aberrations present.
On the bottle of "Scrubbing Bubbles" I see it is very sharp (I've gotten similar results with a 55/1.2), but the bottle directly to its right is not, even though they are the same distance from the lens. In fact, I have a hard time finding anything else truly sharp in the entire frame, other than a tiny bit of counter edge to the left of the subject and closer to camera.
I've used a few fast or relatively fast lenses, and they all suffer from the usual and normal aberrations to one degree or another, inhibiting their sharpness anywhere near wide open. I'm sure most are familiar with these optical "defects" such as vignetting/light fall-off, coma, chromatic aberrations, reduced contrast, etc. Even lenses that aren't "fast" are almost never at their best wide open, and improve dramatically by closing one or two stops.
I've never seen a mild telephoto to wide angle be sharp corner to corner wide open, or even closed two stops. There is always some residual aberration that doesn't reduce or disappear until maybe f/5.6 and beyond.
I'm anxious to see 100% enlargements from high pixel full frame cameras of at least 16MP (try 1Ds2, 5D2, or 1Ds3) to show me the error of my experience. f/2 or f/2.8 corner-to-corner sharpness is very uncommon at any focal length from my experience (super-teles being the exception). Even my macro lenses with their flat fields are lacking in the corners and overall image frame until stopped down slightly.
So, if you have a high MP camera body and can show edge-to-edge, corner-to-corner sharpness at wide apertures, bring it on, I'm sure I would not be the only one delighted to see!
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