If you're going to benefit from the amazing image quality that the Carl Zeiss Apo Sonnar T* 2/135 ($2,122 list) delivers, you're going to have to live with focusing manually and be prepared to part with a good chunk of change. If you're not familiar with Zeiss naming conventions, the Apo Sonnar has a 135mm focal length and a maximum aperture of f/2. The lens, which is available for Canon and Nikon cameras, is nearly double the cost of native autofocus equivalents, but it's not too far off in price from the Sony Carl Zeiss 135mm f/1.8. That lens isn't quite as sharp, and can only be used with Sony D-SLRs, but does support autofocus. Despite the price tag, the build quality and optical performance of the Apo Sonnar T* 2/135 make it worthy of our Editors' Choice award—it's simply a perfect lens from an optical standpoint.

As impressive as its imaging capability is, the Apo Sonnar is not a small lens. It measures 5.1 by 3.3 inches (HD), weighs about 2 pounds, and its front filter thread is compatible with large 77mm filters. Using the included metal hood adds a few inches to the front of the lens, but will prevent flares and improve contrast. The close focus distance is 2.6 feet, which equates to 1:4 magnification—a quarter of what you'd expect from a good 100mm or 150mm macro lens. The Nikon mount version of the Apo Sonnar does have a physical aperture ring, so you can use it on older film bodies; the Canon version does not, but it's not a concern as even the oldest Canon EOS cameras support electronic aperture control.

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I shot a few images with the lens and the Nikon D800SEE IT before running tests through Imatest. The photos looked good and sharp, with a lovely out-of-focus rendering when shot at wider apertures; but I was surprised to see just how sharp the lens was according to our SFRPlus test chart. We use a score of 1,800 lines per picture height using a center-weighted testing method as the cutoff point for an acceptably sharp image. At f/2 the lens scores 3,357 lines on that test, with the extreme edges notching 3,200 lines. Stopping down to f/2.8 increases the score to 3,668 lines, and resolution increases steadily as you close the aperture. It peaks at 3,887 lines at f/5.6. Distortion is virtually nonexistent, so straight lines will remain perfectly straight in your photos.

The Carl Zeiss Apo Sonnar T* 2/135 is one of those lenses that stands out in the crowd. Even though it doesn't support autofocus, shooters who are willing to forgo that convenience will be rewarded by a lens with exemplary optics and gorgeous out-of-focus rendering. The fast aperture will let you create an extremely shallow depth of field, especially when working close to your subject, and you can shoot the lens wide open without sacrificing image quality. Yes, it's expensive, but this is a case where performance actually exceeds the asking price. As such, the Apo Sonnar earns our Editors' Choice award.