Lenses that cover an ultra-wide field of view have always been a niche product. They’re expensive to design, aren’t as versatile as those with a more moderate wide-angle or standard-angle field of view, and plenty of skill is required to use them to their fullest potential. The Carl Zeiss Touit 2.8/12 ($1,250 list) is no exception. It delivers impressive sharpness and a wide aperture, all while capturing a 99° diagonal field of view—the equivalent to an 18mm lens on a full-frame camera. It’s the widest prime lens available for either camera system. Fujifilm offers a 14mm f/2.8 lens for its X system, priced at $899, and Sony sells a 10-18mm f/4 zoom for NEX cameras.
The lens measures 3.2 by 2.6 inches (HD) and weighs about 9.6 ounces. It accepts 67mm front filters, includes a reversible petal-style hood, and features a metal lens barrel with a rubberized focusing ring. The Fuji version has an aperture ring, but the Sony version doesn’t include one—you’ll control the aperture from the camera body when shooting with an NEX camera. It can focus as close as 7.1 inches, which lets you get quite close to your subjects. It’s not a macro lens, but if you work close you can capture details in your subject and still show the background behind it. The Fujifilm 14mm lens can focus just as close, but the Sony 10-18mm zoom’s close focus is limited to 9.8 inches.
I used Imatest to check the sharpness of the lens when paired with the Sony Alpha NEX-5N. At f/2.8 it scores 1,817 lines per picture height on a center-weighted sharpness test. This is better than the 1,800 lines we require for a photo to be considered sharp, but the edges are very soft at 1,239 lines. The resolution improves marginally as you stop down—it peaks at 2,006 at f/5.6, which is also the stop at which the edges sharpen up to 1,763 lines. Shooting at f/8 is recommended for scenes that call for edge-to-edge sharpness—the lens captures just over 2,000 lines there, with edges at 1,790 lines. Barrel distortion is a reasonable 2.3 percent, which is good when you consider the size of the lens and its angle of view. The slight curve this distortion creates can be corrected with ease in Lightroom. The Sony 10-18mm zoom is also sharp at 10mm and 14mm, exceeding 1,800 lines at both focal lengths. But it can only capture half the light as the 12mm f/2.8 at its widest aperture. It does feature optical stabilization, which the Zeiss lens lacks.
As with all wide-angle lenses, some practice and care is required to get the best results. Even though the barrel distortion produced by this lens is reasonable, there is still some evidence of rectilinear distortion around the edges of the frame—this can make objects towards the sides of your photo appear to be stretched. If you’re shooting a landscape this won’t be a big issue, but it can rear its ugly head if you’re taking shots of people. To minimize it you’ll want to keep important subjects centered, and always try to be parallel to your subject—being a bit askew will only amplify the effect. As such, this isn’t the best lens for casual snapshots, as it’s a little too easy to distort the features of people in your photos. You should also try and keep the camera level and plumb to your subject when shooting architecture, as a few degrees of tilt can cause photos to keystone—the top of a building will appear to be narrower than its base. It’s always best to back up, shoot level, and crop out unwanted bits of grass or asphalt later on when photographing a building with a wide-angle lens.
If you’re a wide-angle shooter with an NEX or Fuji X camera, the Carl Zeiss Touit 2.8/12 is an appealing lens. It’s very sharp, and when shot at the narrow apertures that landscape photographers often use, it delivers images that are impressive even at the edges. Distortion is reasonable when you consider its focal length, and the f/2.8 aperture makes it possible to use handheld in less-than-ideal lighting conditions. The Sony 10-18mm lens is also sharp, but it’s a full stop slower. We’ve not yet tested the Fujifilm 14mm lens to compare its performance, but users have reported that its edge performance is disappointing when compared with the Zeiss lens. At $1,250 the Touit costs more than many cameras, but if it’s a focal length that agrees with your shooting style, it’s worth the premium.
Copyright © 2012 Ziff Davis, Inc