Originally posted by BigMackCam My subjective analysis was based on the MTF figures at Photozone for each lens... And yes, F11 shows to be worse than F5.6 on those lenses but still very good on several of them.
you can learn a lot with mtf chart test numbers, but in the end it can only tell you what the lens might do with targets that are shot at the test distance, generally ~1'-6' away from the camera.
"Focus Distance - At Lensrentals we've got targets ranging in size from 24" to 85" in diameter. But that means on the very largest targets we're testing wide angle lenses very close to the target. For example a 24mm lens is tested at about 6 feet shooting distance. A 14mm we're shooting at about 3 feet from the chart.
Making the assumption that the sharpest lens at 3 feet shooting distance is the sharpest lens at infinity is, well, weak. There have been several examples where target analysis reviews say a wide-angle lens is just great, but in the field, shot at infinity, photographers unanimously say it's not that great. And now you know why I don't really trust these tests on wide-angle lenses.
The same problem comes up with macro lenses. My first Imatest results showed that the Nikon 105mm f/2.8 Micro just wasn't that great. But, guess what? Even with my smallest charts I was shooting it at an 8-foot distance. When we developed techniques using high-resolution backlit Imatest targets shot at 1 foot distances more appropriate for a macro lens, it turned out to be a great lens. I ended up writing a blog post saying, yet again, I was wrong less correct than I had hoped to be."
LensRentals.com - There Is No Perfect Lens Test, Either
i bought the imatest software, printed up a nice sharp 20x30 target on the costco printers, and ran a couple of hundred images through it... i found that for mtf testing, a real-world repeatable test scene was much better... for example, look at how rishi at dpr shoots these big wide cityscapes, at all apertures:
Prepare to be impressed: Tamron 15-30 F2.8 vs. Nikon 14-24 F2.8: Digital Photography Review Sony Zeiss Distagon T* FE 35mm F1.4 ZA samples: Digital Photography Review
online mtf chart numbers won't tell you anything about how good your particular lens is; half of all the legacy lenses that i've tested have been decentered... you can't test for that by shooting centered objects like dogs and people, it really needs to be wider long shots, of equidistant objects.