This digital-only, 27-88mm equivalent ($1,000, street) is a pro-caliber upgrade of Canon's popular 17-85mm amateur Image Stabilizer lens ($515, street). It has the hallmarks of Canon's professional, full-frame L-series (solid construction, aspheric elements, UD glass). But it couldn't be labeled "L" because it won't work on all EOS bodies.
HANDS ON: About an inch longer and half a pound heavier than comparable Sigma and Tamron high-speed digital-only zooms, it has a solid feel, with smooth-turning zoom and focusing rings. AF action is fast, accurate, and -- thanks to the Ultrasonic Motor -- almost silent.
IN THE LAB: SQF tests found Excellent sharpness and contrast at all tested focal lengths. Our DxO Analyzer 2.0 tests uncovered Slight barrel distortion at 17mm (0.29%), and Slight pincushion distortion at 35mm (0.22%) and 55mm (0.21%). This is equal to or better than the comparable Nikon, Sigma, and Tamron f/2.8 lenses, and a dramatic improvement over Canon's amateur 17-85mm f/4-5.6 IS lens.
Light falloff left the corners by f/5.6 at 17mm and by f/4 at 35mm and 55mm -- again a step above Canon's 17-85mm IS. Magnifying power was okay, with maximum magnification ratios at the uniform close-focusing distance of 13 inches ranging from 1:14.3 at 17mm to 1:5 at 55mm. Lab tests of the IS system based on DxO blur factor readings for exposures made at 55mm by three different shooters showed between 1 and 3 stops of extra handheld sharpness when IS is engaged. Sounds low, but it's not surprising since IS shows its most dramatic gains at long focal lengths.
CONCLUSIONS: This lens is a natural for photojournalists, as well as event and wedding photographers who need to work in ambient light without the mood-crashing intrusions of flash and/or tripod.