Canon EF 17-40mm f/4L USM Lens Reviews

The Canon EF 17-40mm f/4L USM lens is an affordable L-series ultra-wide-angle zoom lens that’s ideal for both film and digital SLRs. Superior optics are assured by the use of three Aspherical lens elements, in addition to a Super UD (Ultra-low Dispersion) glass element. Optical coatings are optimized for use with digital cameras. This lens focuses as close as 11 inches (0.28m), and offers both Canon’s full-time manual focus and a powerful ring-type USM for fast and silent AF. It has a constant f/4 maximum aperture, and offers the choice of screw-in 77mm filters or a holder in the rear of the lens for up to three gel filters. Finally, it offers weather-resistant construction similar to other high-end L-series lenses. (Canon)

Sample Images




The Digital Picture

Wide open center of the frame sharpness ranges from great on the wide end to good on the long end. Corner sharpness is the reverse – ranging from good at 40mm to soft in the full frame corners at 17mm. Stopping the 17-40 L down to f/5.6 levels sharpness to very good across the frame. Both of the 17-40 L lenses I’ve owned have yielded better sharpness at short distances than at long distances.

Camera Labs

The EF 17-40mm f/4.0L is one of the best lenses in Canon’s range. It brings you a taste of the truly exotic with ultra-wide coverage, while boasting ‘L’ quality all at a surprisingly affordable price. Sure it ain’t exactly cheap, but it’s considerably more affordable than the EF 24-105mm f/4.0L and almost half the price of the EF 16-35mm f/2.8L.

Fred Miranda Forum User Reviews

A great lens. One of my favorite lenses for landscapes and portraits. My lens has been through a lot, and has survived it all. Very tough build. Its image quality is outstanding. In my comparisons with the 18-55 (Ok, is that really a comparison?), this lens won hands down – the difference was pretty remarkable.

Luminous Landscape (Comparison to 16-35mm f/2.8 L)

The new 17-40mm f/4L is a welcome surprise though. At nearly half the price of the faster and slightly wider 16-35mm f/2.8L it provides excellent image quality, surpassing that of the more expensive lens in several areas.

Photography Review User Reviews

Great build. Feels so sturdy and a serious piece of equipment. I’ve never had USM focussing (ultra-sonic motor) but it’s so fast at focussing I had to keep checking that the focus barrel had changed. The grips for zooming feels very comfortable. I love the full time manual focussing too so you can focus manually even if you are in AF mode.


The Canon EF 17-40mm f/4 USM L showed a very good to excellent performance in the lab as well as during the field tests. The lens exhibited very little vignetting and excellent resolution figures. On the downsode the level of distortions could haven been a little better at the wide-angle setting. Typical for most wide-angle zooms chromatic aberrations can be visible but the problem remains comparatively low. The quality of the construction is next to perfect.

WL Castleman

If you shoot wide angle, full frame photographs with Canon cameras stopped down at f/8 and beyond, the EF 17-40mm f/4L lens is an outstanding lens. Contrast and sharpness are greatest at the wide end (20 and 24mm) of the zoom range and approach or exceed those of quality prime lenses. Sharpness drops off in far corners at 35mm and 40mm and microcontrast drops off slightly at 35mm. Performance drop at the long end of the zoom range is unlikely to be objectionable in most landscape photos. Linear distortion is present as expected for a 2.5x zoom. Overall, this is a high performance superwide angle zoom for full-frame Canon cameras as befits the “L-lens” designation.

SLR Gear User Reviews

The lens is easy to work with, I’d say it’s almost compulsory for anyone using 1.6 crop EOS DSLR as a standard zoom lens. The AF is also fast without hesitation, even under dim light condition and the image quality is on par with its other L brothers and sisters. Furthermore the reason to get excited is the price which is reasonably on the cheap side, taking L quality into account.

Where to Buy

First off, consider going to your local camera store (and I don’t necessarily mean Wolf Camera at the mall). By going to your local camera store, you’re supporting your community and you just might build a lasting relationship with people you can rely on when you need some help or answers. If you’re buying online, I recommend sticking with Amazon, B&H Photo or Adorama. These three vendors are reliable, trustworthy and generally have the best (legitimate) prices. Additionally, purchasing your gear through these links helps support this site.

[tags]Canon, EF, 17-40mm, f/4L, USM, lens, review[/tags]