Camera Accessories

The 'EF-S' designation is Canon's way of labelling lenses with Short Back Focus, which indicates the distance between the sensor plane and the rear element of the lens is shorter than in an EF lens. Such lenses are designed exclusively for EOS cameras with 'APS-C-sized' sensors and cannot be used on Canon's 35mm SLR cameras - or on the EOS 5D. The new EF-S 10-22mm ultra-wide-angle zoom lens covers fields of view equivalent to 16-35mm in 135mm format. An excellent partner to the EOS 400D we used for our tests, its wide angle of view is great for landscape and architectural photography, especially indoor shots.

Compact, light and robustly built, the EF-S 10-22mm lens provides a wider angle of view than the kit 18-55mm lens supplied with non-professional EOS cameras. Its construction includes three aspherical elements as well as a super-UD glass element. Together they promise high image quality at all focal lengths. In our tests, Imatest showed the EF-S 10-22mm lens to be capable of delivering high resolution across its focal length and aperture range, although resolution deteriorated slightly when the smallest apertures were used.

Best performance was found between f/5.6 and f/11. Edge-to-edge sharpness was excellent and we found evidence of slight vignetting in exposures shot at the widest lens apertures. The effect was most noticeable at the 10mm setting but traces remained right up to 22mm. Stopping down to f/5.6 minimised the effect. Vignetting was more severe when the lens was used with the EOS 400D's built-in flash, which only covers angles of view out to 17mm.

Imatest showed lateral chromatic aberration to be negligible. Barrel distortion was visible at the 10mm setting, as you would expect for such a wide-angle lens; but it disappeared by about 15mm. Slight pincushioning was detected at 22mm, but not enough to affect general photography.

Flare was extremely well controlled and almost always absent in backlit shots, unless the lens was pointed towards the sun. Even then, it was less than most lenses produce. Internal focusing lets you shoot with angle-critical filters like polarisers and graduates. Autofocusing was fast and accurate, thanks to a combination of Canon's ring USM and new AF algorithms. Manual focusing was also easy to use. The EF-S 10-22mm lens accepts 77mm filters, although we found a tendency to vignetting with polarisers at the widest focal length setting.
Canon claims the EF-S 10-22mm f/3.5-4.5 USM Lens has a circular aperture design that delivers attractive bokeh (defocused background/foreground blurring). However, actually achieving the shallow depth of field required to see this phenomenon in normal shooting conditions is very difficult because its inherent depth of field is very large, even at wide apertures.

Our main gripe is that the lens is supplied without a lens hood, an accessory we consider vital for this type of lens. The EW-83E hood will set you back about $70.

IMATEST GRAPHS

SAMPLE IMAGES

The wide angle of view is superb for landscape photography.

It's also excellent for interior shots - but note the slight vignetting caused by the camera's built-in flash.

Flare was extremely well controlled....

... even when the lens was pointed towards the sun.

Maximum aperture: f/3.5-4.5

Minimum aperture: f/22-27
Lens construction: 13 elements in 10 groups
Minimum focus: 0.24 m
Filter size: 77mm
Dimensions (Diameter x L): 83.5 x 89.8 mm
Weight: 385 grams