Despite lacking the L branding this lens is a good quality item of kit, as indicated by its price. The build quality feels right with all the switches and rings having that positive smoothness of operation to them.

Good build quality with smooth operations; Excellent Image Stabilisation; Good image quality; Popular Filter size

Expensive with no-upgrade path; Distortion at the longer focal length; Slightly bulky for focal range

Dont get me wrong, this is optically fantastic, its like having a bag full of primes on your camera. My list of cons is long and I'm being very picky with them - but the zoom creep is the most troublesome for me.

Stunning image quality (wide angle distortion excepted), f2.8, IS, super fast focussing, good size and weight; DPP lens profile to correct distortion

For the very high "L" level pricing it should have better build quality; not suffer chronic zoom creep; not have so much distortion at 17mm; and it should be weather sealed

A quality modern mid range zoom for 1.6x crop with all the bells and whistles, constant F2.8, IS & USM. A bit soft at wide end at 2.8 which becomes sharper at f4. Like to see this lens upgraded to L quality for around the same price. Shoots good images but so does the 17-85 at f4.

Good images; IS; mid range zoom

Little Soft wide @2.8

The Canon EF-S 17-55mm f/2.8 IS USM is the fastest standard zoom dedicated to Canon's APS-C DSLRs, and is designed to be an upgrade for disgruntled kit lens owners who want better image quality.

The premium standard zoom for APS -C sensor cameras usually covers the range from around 17mm to around 50mm and has a maximum aperture of f/2.8. In 35mm terms this coverage is equivalent to something like that which a 27-80/2.8 zoom would have on a full frame camera.

The large circular aperture produces a shallow depth-of-field, creating background blur that draws attention to the photographic subject. The lens construction includes UD and aspherical elements, which deliver impressive image quality throughout the entire zoom range.

It's the nearest thing to a pro-grade Canon EF-S standard zoom...

Fast; consistent; accurate autofocus; Generous f/2.8 maximum aperture

Big for an APS-C lens; No weather seals

Canon's EF-S 17-55mm f/2.8 IS USM is a premium zoom lens designed for EF-S bodies and announced alongside the EOS-30D digital SLR in February 2006. Boasting a constant f2.8 aperture throughout the range, it's the fastest standard focal length zoom lens available for Canon EF-S mount digital SLRs.

CanonEF-S 17-55mm f/2.8 IS USM Strengths: You get what you pay for with respect to image quality with this lens. The EF-S 17-55mm f/2.8 IS had 50% MTF and resolution scores closest to L-lenses or primes across the focal lengths tested.

The EF-S naming refers to the S hort-back focus design which is only compatible to APS-C EOS SLRs starting with the EOS 300D (Digital Rebel). EF-S lenses feature a protruding rear element which requires a special mirror design to avoid a collision of the mirror and the rear part of the lens.