Canon EF 28-135 f/3.5-5.6 IS USM zoom lens

IS adds two to three stops to your ability to shoot sharp photographs without a tripod. Thus at the wide end, you can shoot 1/8th second exposures handheld without paying a penalty in sharpness. That's great for available light junkies. While you could shoot the same speed at a larger aperture - f/1.8 say, instead of f/3.5 - you'd pay a penalty in depth of field.

The autofocusing is as quick and quiet as you would expect with Canon's ultrasonic motor (USM), which also allows manual control while autofocus is engaged.

This lens is built almost entirely of plastic, although the mount itself is metal. It also has a disconcerting looseness to its construction, though this never seems to interfere with its operation. I've had mine about three years and have never babied it. It developed a tight spot in the zoom action after I bunged a rock with it while walking a breakwater one day, but the tightness worked out with time. I don't expect it will take nearly as much abuse as an L series lens, but then it doesn't cost as much, either.

Sharpness freaks take note: The lens is not terribly sharp wide open at any focal length but it is fine by about f/8.

Cost is about $400 new at reputable mail-order houses. They occasionally come up on the used market for not a lot less.

Dec. 19, 2004