This page has the least to do with lens performance. These lenses are almost identical in sharpness.

Amateurs run to this page first, even though it's the least significant. The same amateurs who consider this so important are also the ones most likely to have sloppy technique which will prevent them from getting sharp images. See my page on How to Get Great Sharpness and The Resolution Myth.

I'm showing the comparisons below at very high magnification so you can see these small variations. If you printed an entire image at the same size as these comparisons (shown at 100% on screen) you'd have a print over three feet wide! Only geeks look at three-foot-wide prints as close as you 're looking at your screen.

This first image is the entire uncropped image. I reduced it to fit your screen. The red box shows the snippet I took from each image to show at 100%.

I made these on a Nikon D200, large normal JPG, "optimum quality" compression, tripod. The same equivalent manual exposure was used for all shots. My D200 had to be unset from its automated defaults of automatic sharpening, white balance and contrast. If you forget to undo these you'll have your camera tweaking WB, exposure, sharpness and contrast all by itself from shot to shot, confusing the results and hiding any differences between lenses.

I saved the crops at 80% quality in Photoshop's ImageReady's Save-to-Web, which means they look identical to what I saw on my screen. RAW images looked the same. JPGs saved my time and disk space doing all this work to compare.

I would never see any difference in real photography. I spent hours devising a scheme to show what few differences there are between lenses below.

I'd never see any difference in real photography because these differences are only visible at large apertures. Large apertures' depths of field are so shallow that few things, if any, are in sufficiently perfect focus to show sharpness differences. Only if you shoot at infinity, as I did here, can you see anything.

Focusing errors at large apertures for real subjects at real distances completely obliterate any differences between lenses. At f/1.4 with a manual focus lens the focus indicator on my D200 is not precise enough to ensure perfect focus. I never got consistent perfect focus on my manual film cameras' split image or microprisms either because our eyes aren't good enough. To focus a manual focus camera sufficiently accurately requires a viewfinder microscope.

I made these shots at infinity and used each lens' infinity stop. The green focus confirmation light in my D200 is not precise enough to ensure sharp focus at f/1.4. My D200 focused best if focused on the closer point at which the light went between ON to OFF. Focusing in the middle of the light's ON range tended to be focused past the subject. I didn't focus here: I left each lens on its infinity stop.

The lenses are focused at their infinity stops, all of which were perfectly accurate. I devised this scene to include a car and palm tree and homes at 550 feet in the top and center of each crop. The palm and purple plant towards the bottom are at 350 feet, and the vegetation on the very bottom is at 225 feet. This lets me show the effects of focus shift. Look for difference at the middle and top of each shot, where the lenses are focused. Look at the bottom only to see what's going on with depth of field and focus shift. 550 feet is close enough to infinity for this test. You will see different sharpnesses on the closer brush, which again shows you how difficult it is to define the sharpest lens.

Corners