Review: Go Wide with the Canon EF 17-40mm f/4.0L USM

The Canon EF 17-40mm f/4.0L USM is a wide-angle zoom lens that is very capable on full frame and crop sensors (equivalent focal length 27-64mm), extremely solid and built for everyday wide-angle use. If wide-angle is your thing, then this zoom will give you great quality across its focal range.


The 17-40mm benefits from weather sealing, with 12 elements in total, three aspherical and a Super UD (Ultra-low Dispersion) element. The ring-type ultrasonic focus motor is the usual silent and fast functionality you get with Canon, which provides crisp autofocus and smooth manual focus when needed. The maximum aperture on this lens is f/4 up to f/22. Is always a great bonus to have f/2.8 on a zoom lens, but for the majority of everyday scenarios, f/4 should do you well, especially when an f/2.8 can cost considerably more.

Minimum focus can be up to 0.28m, not exactly macro, but still a reasonable distance as long as you are mounted on a tripod. It also weighs in at 500g (1.10 lb) with the length being a nice, compact 97mm. Compact and lightweight is something we wish all zooms could be. The filter thread is 77mm which is pretty standard for a Canon lens.

Focusing is done behind the filter threads, with no external movement. Using a circular polarizing or neutral density filter will give no rotation, which will be of benefit on this lens. The 16-35mm f/2.8 is 82mm, so bear that in mind if you bought this one first. There is no image stabilization on this lens, but it’s not really necessary for this focal length.

In total, this is a very compact and solid lens with the build quality would expect from a Canon L series.

Image Quality

When the lens is wide open image sharpness is very good, with even the corners being quite sharp. As you’d expect on an f/4 lens, the best sharpness comes in at f/5.6, with landscape type images looking good at f/8-f/11.

Being ultrawide angle you would expect some flair at times and even distortion and chromatic aberration, but this lens copes well in all these areas, being not too overbearing. If you go below 24mm you’ll start to notice some anomalies, but these can be corrected in post editing. There will be some barrel distortion at 17 mm and in cushioning up to 40 mm, but 24mm is probably the sweet spot. Close-up you’re going to notice these characteristics more, but for things like landscapes, this lens looks fantastic. If you’re using this lens on a full frame body you’ll start to see vignetting at 17mm, but perfectly adequate at 40mm. Again, this can be remedied in post-editing.

On a crop sensor, the equivalent range of 27-64mm will work quite well for this all-around lens. It won’t be too overtly wide-angle and will still cover the traditional standards around 50mm. A bit like the 24-70mm if you want a general everyday lens, but err towards wider angled images. If you’re taking group images at the lens’ widest setting, you might want to keep them away from the very edges to reduce any distortions.

One or two reports I’ve seen say that the lens can be soft at times. This may depend on how wide open you have the lens and how near to your subject, but I found at a reasonable F stop this lens is very sharp. As the lens is quite a few years old it may be that it will simply need calibrating on some camera bodies. This you can easily do manually if you search for some YouTube videos on the subject or you can use software such as Focal.

This lens will serve very well for landscapes, groups or even portraits at a push, just don’t get too close. It would be an ideal lens for landscape photographers if you are used to a decent amount of light and will probably always shoot over f/8. If you want the extra heft of an f/2.8 and have the money, then there are some other options.

How Does It Compare?

Quality wise, this lens is as good as you would expect from the Canon L series, especially at this price. It may not be as fast as the Canon EF 16-35mm f/2.8L lens, but it’s around half the price. The 16-35mm will let in twice the light but it’s twice the price, so in many ways, you get what you pay for. The Canon EF-S 17-55mm f/2.8 IS USM has environmental sealing and is also better in low light.

Some reports that this lens has been used for concert photography say that this its perfectly adequate, but if you want that extra stop of light, then the 16-35mm may be a better fit. The Canon 16-35mm f/4 IS may be a better fit if you shoot a lot of videos, with its built-in image stabilization. If you shoot predominantly landscape photography, you can’t go wrong here.

Canon 17-40mm f/4.0LCanon EF 16-35mm f/2.8L
Focal length17-40mm16-35mm
Max. aperturef/4.0f/2.8
Filter size7782mm
Optics12 elements in 9 groups14 elements in 10 groups


If you want ultrawide angle and you’re happy with narrow apertures without spending a ton of money, then the 17-40mm f/4.0L could definitely fit your needs. Being f/4 it may not cope the best in very low light, such as indoors without a tripod or flash, in which the 16-35mm L would fare better, but in many cases, it’s what you can get for your money.

If you want an everyday wide-angle lens at a reasonable price then the 17-40mm f/4.0L is a no-brainer. It’s built extremely well and works great on 1.6x and full frame bodies. Its very well suited to landscape photography or even reasonably near, wide-field of view images. The lens can also be used on architecture and real estate if you don’t mind a bit of regular post editing. The post editing is required at its very widest to remove barrel distortion and to keep those lines straight.

The lens could be good for group shots and full body images, but if you get too close to the subject you will start to get aspects of the subject getting quite distorted. Essentially, a quality lens with everything Canon throws into its L lens at a reasonable price.

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