Are these two lens samples representative? I can't say for sure. I've been using my 16-35mm f/2.8L for many months and have been happy with the images it produces. Is it as sharp as primes in this focal length range? No, of course not.

Originally posted 2006-08-04 on Optyczne.pl The Canon EF 17-40 mm f/4L USM was introduced in May 2003 as an ultra wide-angle lens designed for digital and analog cameras with a 35 mm frame detector.

USM motor autofocus could make less mistakes; We expect better resolution from the L-grade lens

The EF 17-40mm f/4L USM lens is a member of a suite of Canon zoom lenses that retain a constant f4 maximum aperture throughout the zoom range. Designed for use on 35mm SLR cameras, this ultra-wide zoom is ideal for capturing dramatic landscape shots and taking portraits of large groups of people.

I query some of these reviews because they are not accurate. Lets look at the 17-40 l. I shot a wedding using this lens ona full frame 5D MK2. when i viewed the results on my computer all the group shots were so bad at The 17mm they were unuseable distortion was horrific.

non beware review strapped to an apc sensor

very high distortion at 17mm end overpriced and heavy

The Canon EF 17-40mm f/4L USM ($839.99 direct) is an ultra-wide to normal zoom lens that is compatible with Canon EOS SLR cameras . When used on a full-frame body, the lens provides an extremely wide 17mm field of view on the wide end with a 2.4x zoom factor that takes it to a normal 40mm field of...

Ultra-wide field of view; Reasonable price tag; Good center sharpness

Muddy edges and corners at 17mm; Some distortion; Noticeable color fringing

Canon understands the underlying inimitability of each photographers creative vision, and thus proffers an exclusive camera lens to vivify their imagination. Each piece from the excellent array of Canon lenses is truly reflective of the signature know-how and craftsmanship associated with Canon.

Gary Wolstenholme takes a look at this popular lightweight ultra-wide angle zoom lens, which has a constant aperture of f/4, an Ultrasonic focusing motor and sealing against the elements.

Superb performance in the centre throughout the range; Well built; Lightweight

Sudden softness in the corners may disturb full-frame SLR users; Distortion difficult to correct entirely at 17mm; Falloff at 17mm

This article reviews the full frame performance of the Canon EF 17-40mm f/4L lens. My intented use of the lens is for landscape photography with a Canon EOS-1Ds camera. The EF 17-40mm f/4L lens (left panel) is a very sharp, high contrast zoom lens with performance characteristics that often match...

The Canon EF 17-40mm f/4L USM ($839.99 direct) is an ultra-wide to normal zoom lens that is compatible with Canon EOS SLR cameras. When used on a full-frame body, the lens provides an extremely wide 17mm field of view on the wide end with a 2.4x zoom factor that takes it to a normal 40mm field of view at the long end. It features a constant f/4 aperture and a silent focusing motor. The lens is a part of Canon's top-end L series of lenses—which are easily identified by the red band around the front element. It isn't as sharp as the Canon EF 16-35mm f/2.8L II USM($1,745.00 at Amazon), and is prone to showing color fringing around highlight edges. But if you're looking for an ultra-wide zoom and you're on a budget, some work in Lightroom can make up for its shortcomings. The lens is short and squat at 3.8 by 3.3 inches (HD). It weighs about 1.1 pounds, and uses rather large 77mm filters. The lens can focus as close as 10.8 inches, regardless of the focal length. There's a large man...

The Canon EF 17-40mm f/4L USM lens is an inexpensive alternative to the 16-35mm f/2.8, but its edges are muddy at its widest angle.

Ultra-wide field of view; Reasonable price tag; Good center sharpness

Muddy edges and corners at 17mm; Some distortion; Noticeable color fringing