The Canon EF 28mm f/1.8 USM ($509.99 direct) is impressively compact when you consider its wide-angle field of view and fast aperture, but there are some optical compromises that you should be aware of. It is compatible with both APS-C and full-frame Canon D-SLR cameras. It's a relative bargain—Canon also offers an EF 28mm f/2.8 IS USM lens with image stabilization that sells for $800, even though it captures less light at its maximum aperture. The lens isn't as sharp as Nikon's take on the design, the AF-S Nikkor 28mm f/1.8G, which impressed us enough to earn our Editors' Choice award.

The EF 28mm measures just 2.2 by 2.9 inches (HD) and weighs about 10.9 ounces. It can focus on objects as close as 0.8-foot from the front of the lens. It is by no means a macro optic, but keeping the aperture wide open and focusing at the minimum distance allow you to capture images with a shallow depth of field. Standard 58mm filters are supported, and there's no movement at all when focusing so using a polarizing filter is possible. A lens hood is not included.

I used Imatest to check the sharpness of the lens when paired with the full-frame EOS 6D. At f/1.8 it was disappointing, scoring only 1,346 lines—well below the 1,800 lines per picture height that mark a sharp image. Stopping down to f/2.8 rectified this, improving to 2,020 lines, and the resolution peaks at f/8, where it records 2,396 lines. Distortion isn't relevant in the field—the EF 28mm shows only 0.5 percent barrel distortion—Lightroom includes a lens profile that will correct this with one click. Another 28mm option for Canon shooters is the Carl Zeiss Distagon T* 2/28. It is sharper than the Canon lens at f/2, where it records about 1,622 lines, but also sharpens to over 2,000 lines by f/2.8. It's a manual focus lens, however, which may steer some shooters away, but it's build quality is excellent and there is something unique about the character of the images that it captures that no lab test can capture.

A low resolution at f/1.8 isn't a deal breaker, especially when you consider the size of the lens, its price, and its performance from f/2.8 onwards. However, the lens is very prone to color fringing in high contrast scenes, regardless of the aperture. In my tests, dark branches against a blue sky showed purple fringing on one edge and green fringing on the other. This can be corrected in Lightroom, but requires a bit more work to eliminate—you'll have to adjust the amount of fringe reduction and pinpoint the hue of what you'd like to eliminate using slider tools. Canon shooters obviously can't use the Nikon 28mm lens on their cameras, but may want to consider the Sigma 24mm F1.8 EX Aspherical DG DF Macro lens as an alternative. Its field of view is a bit wider and the lens itself is larger, but it is priced in the same ballpark—its list price is $580—and it scored 2,100 lines per picture height at f/1.8, a score that increased to 3,000 lines at f/5.6.

If you're in the market for a wide-angle lens for your Canon D-SLR, the EF 28mm f/1.8 USM is likely on your radar. Even though it can capture a lot of light, the sharpness at f/1.8 isn't as good as it is on some other lenses and you're going to encounter a good deal of color fringing in high contrast scenes. If you aren't married to a camera system, our Editors' Choice Nikon AF-S Nikkor f/1.8G is a better lens that matches the Canon's field of view and aperture, but Canon shooters shouldn't count out the 24mm F1.8 EX Aspherical DG DF Macro—it's just as fast, offers a slightly wider field of view, and is extremely sharp—and it's only priced $70 higher than the Canon.

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