Updated on July 6, 2014 – After relying on this lens for nearly 10 years, I am about to replace it with a Canon EF 16-35mm f/4 L IS, a lens that just recently became available. (I’ll review that lens a this blog after I have a chance to use it.) With this change in mind, I am updating this post one more time.

The Canon EF 17-40mm f/4 L lens has long been a core lens in my kit, covering the wide to ultra wide angle range on my full frame cameras. For my primary uses it is a great performer. It is almost always in my kit when I backpack, and I often use it for landscape photography and occasionally for other types of photography, too.

As I have written elsewhere, every lens has a “personality” that makes it more or less suited to different types of photography and different photographers. This personality is the result of the relative strengths and weaknesses of the lens. No lens is objectively “best” in all ways, so the real interesting question is how well various lenses line up with your specific needs. With that in mind, here are some observations about the 17-40 based on nearly a decade of use since 2005.

• Overall, the lens is capable of excellent resolution.  Center sharpness is good at all apertures (leaving aside for the moment the effects of diffraction blur that will soften the image from any lens at very small apertures) and it can be quite good when the lens is stopped down a bit. It is important to note that ultra wide zoom lenses (and even prime lenses) can have some issues with sharpness and other factors such as chromatic aberration, especially in the corners of the frame. This lens is not immune to these issues of ultra wide lenses, though it handles most of them quite well in many cases.
• Corner sharpness varies depending upon aperture. In my experience, the lens shows noticeable corner softness at f/4. Whether or not this is a problem depends a lot on how you will shoot the lens and what your expectations are. I have used the lens wide open for street photography in closed-in spaces, and the soft corners added a character to the shots that I liked. If you require something closer to corner-to-corner sharpness wide open, the Canon EF 16-35mm f/2.8L II is likely to be a better choice if you mainly shoot low-light, hand-held, full-frame work. (Read more about the 16-35mm options later in this post.)  However, if you are looking for an ultra wide zoom to shoot more static subjects from the tripod and you will use smaller apertures for larger depth of field, the 17-40 is just as good – and lighter and less expensive to boot. Stopped down a bit and on the tripod, the 17-40 produces excellent results.
• In mid-2014 Canon introduced another alternative lens, the EF 16-35mm f/4 L IS. This lens offers significantly better corner performance that either of the earlier lenses along with image stabilization. This lens offers significant improvements to corner performance, a narrower focal length range, and a price that is roughly between that of the 17-40 and the f/2.8 16-35. (Read more about this option later in this post.)
• The lens has a great reputation for resistance to flare, and my experience is in line with this. This may be more important in an ultra wide lens since its wide field of view is more likely to include the sun or other flare-producing light sources, and because the shallow lens hoods that are required for ultra-wide lenses don’t really shade the lens much at all.
• Build quality is just what you would expect in an L lens, and there is something about the compact and simple nature of this lens that seems to give it an even more solid “feel,” for whatever that might be worth. Along these lines, it uses 77mm filters, which are very common on other L zooms.

On full frame, this lens complements any of the 24mm-xxmm L zooms. It does overlap their focal length ranges a bit, but I find that useful for several reasons. (I shoot the EF 24-105mm f/4L IS and the EF 24-70mm f/2.8 L II. (See more about these lenses here: “Canon 24-70mm f/2.8 L II vs. 24-70mm f/4L IS vs. 24-105mm f/4 L IS“) First, it means that I am a bit less likely to need to change lenses. Second, it means that I can sometimes stay away from the ends of the focal length ranges of either lens, and this can produce just a bit more image quality in some cases.

Some photographers combine the 17-40 with a Canon EF 70-200mm f/4L IS USM lens (link to B&H) and then add a 50mm prime to “fill the gap.” I don’t do this, but I can understand how it could work well and save some weight and bulk.

The 17-40 f/4 L on Cropped Sensor Bodies

Some photographers like to use this lens on their cropped sensor cameras. I used mine on a cropped sensor body for the first year or so that I owned it, but I’ve used in exclusively on full frame bodies since that time. In my view it is merely OK on cropped sensor cameras, but not a stand out performer. The main issue is that, in my experience, you end up caught between the proverbial “rock and a hard place.” The “rock” is the relatively conservative f/4 maximum aperture with its less than stupendous corner performance. The “hard place” is the issue with diffraction blur occurring sooner as you stop down on cropped sensor cameras – many feel that you would want to be cautious about stopping down much past f/8 for this reason on crop. This doesn’t leave you with a lot to work with: f/4 is a bit soft in the corners. f/5.6 is getting better but isn’t yet great. f/8 is pretty good all around. At f/11 diffraction blur starts to become a concern. In the end, you really have only one truly good aperture. Fortunately, cropped sensor camera shooters have a great alternative in the Canon EF-S 17-55mm f/2.8 IS USM Zoom Lens. It provides better large aperture performance, a wider range of apertures at f2.8, image stabilization, and a larger focal length range. For this reason, I tend to recommend it over the 17-40 for cropped sensor shooters.

Cropped sensor shooters contemplating an ultra-wide angle lens should be aware that this focal length range does not provide equally wide angle-of-view coverage on their cameras. On these cameras the 17-40mm and 16-35mm focal lengths range from merely wide to a bit longer than normal. Basically, if you shoot a cropped sensor camera and you want ultra-wide… you do not want any of these lenses! Canon does make a lens that provides ultra-wide coverage on your cropped sensor camera though. It is the EFS 10-22mm f/3.5-4.5 lens. This is a fine lens for things like landscape photography, and the angle-of-view coverage on cropped sensor cameras is equal to that of the 16-35mm lenses on full frame.

(Note that these EFS lenses are not designed to work on full frame cameras.)

Compared to the Canon EF 16-35mm f/2.8 L II

The Canon alternative to the EF 17-40mm f/4 L has long been the Canon EF 16-35mm f/2.8L II. (The current, newer version is signified by the addition of “II” to its name.). A few important points include:

• This 16-35mm lens provides one additional stop at f/2.8, which is useful to those doing handheld ultra-wide angle photography. It is a popular and useful lens for things such as journalism, wedding, and event photography for this reason.
• This lens also provide better corner performance at large apertures where the 17-40 shows its corner weaknesses, especially at f/4 and to lesser extent f/5.6 and possibly f/8.
• The 16-35mm f/2.8 II is no better than the 17-40 at smaller apertures, where the 17-40 is at least as good and perhaps marginally better in some ways, so there is little advantage in the 16-35mm f/2.8 for landscape photographers and those doing similar work who may typically shoot such a lens at smaller apertures.
• The 16-35mm f/2.8 II is approximately twice as costly as the 17-40mm lens. It is also larger and heavier.
• The II version of the 16-35mm lens uses a larger 82mm diameter filter thread. (The older version has a 77mm thread diameter, which is common to a number of Canon L lenses.)

Compared to the Canon EF 16-35 f/4 L IS

As of the date of the current revision of this post, Canon had just introduced a new EF 16-35mm f/4 L IS lens that can be an alternative to the 17-40mm f/4 L and, for that matter, to the older EF 16-35mm f/2.8 L II. Some considerations follow:

• Although this lens has the same f/4 maximum aperture as the 17-40mm lens, it adds image-stabilization (IS). IS allows you to hand hold the camera at lower shutter speeds by compensation for camera motion/vibration.
• Every review I have read reports much better corner performance than that of either the 17-40mm f/4 or the 16-35mm f/2.8, including very good performance wide open. The best performance seems to be at the shortest focal lengths, where the coverage does not overlap that of longer zoom lenses. (I will update this section based on my own experiences after I have a chance to use the lens.)
• This lens is larger and heavier than the 17-40mm lens, being more like the 16-35mm f/2.8 in these characteristics. It is priced midway between the other two lenses.
• This lens uses the more “standard” 77mm filter threads.

The Bottom Line

In some ways, this is almost as much a post about options for covering this focal length range as it is about the 17-40 f/4 L itself. It is also a good example of the fact that there is no one “best lens” in a general sense, but that it is really about which lens is right for your particular needs. With that in mind, a quick recap of three options along with some general ideas about situations in which any of them might be a best choice:

• If you use a full frame camera, mostly shoot from the tripod, and tend to favor smaller apertures for greater depth of field and other reasons, then the 17-40mm f/4 L could be the best choice for you. It is smaller and lighter than the alternatives and costs quite a bit less.
• If you want the best overall lens performance performance and can get along with image stabilization and without the f/2.8 aperture, the new EF 16-35mm f/4L IS may be your best option.
• If you use a full frame camera and often shoot handheld in low-light situations and thus need to use larger apertures, the 16-35mm f/2.8 L II could well be the best bet for you. Of course, it can also do much of what the 17-40 will do, though with a higher cost, smaller focal length range, and greater weight and bulk.
• If you shoot a cropped sensor camera the EFS 17-55mm f/2.8 IS is probably a better choice than either of the L lenses for you – with its excellent optical quality, f/2.8 aperture, image stabilization, and larger focal length range.

Bottom line: The EF 17-40 f/4 L is a great lens for full-frame photographers who want a versatile ultra-wide angle lens for shooting large DOF subjects from the tripod, including subjects such as landscape and architecture. Its lower cost, smaller size, and lighter weight are bonuses – the latter two especially so for those who work while traveling on foot.

This lens is available from site sponsor B&H Photo, and your purchase though links at this site help support the blog. If this information was useful to you in making your decision, please consider purchasing through the following link: Canon EF 17-40mm f/4 L at B&H

If the information in this post has helped you arrive at a purchase decision, please consider using these links to make your purchase from site-affiliate B&H Photo. Your price will be the same, you’ll purchase from a reliable vendor, and a small percentage of your purchase price will help support this website. Thanks!

In addition to the Canon EF 17-40mm f/4 L, other lenses mentioned in this article and available from B&H include:

• Canon EF 16-35mm f/4 L IS USM Zoom Lens
• Canon EF 16-35mm f/2.8L II Zoom Lens
• Canon 24-105mm f/4L IS at B&H
• Canon EF 70-200mm f/4L IS USM Lens
• Canon EF-S 17-55mm f/2.8 IS USM Zoom Lens (for Canon cropped sensor cameras only)
• EFS 10-22mm f/3.5-4.5 Zoom Lens (for Canon cropped sensor cameras only)

Related posts:

• Canon 17-40mm f/4 L Sharpness: Two Examples
• Corner Sharpness of the Canon 17-40m f/4 Lens on Full Frame
• Canon EF 17-40mm f/4 L: Testing a Claim About Sharpness and Focal Length
• Canon EF 17-40mm f/4 L at B&H

G Dan Mitchell Photography
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