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The wide zoom—16-35, 17-35, 17-40, 20-35, et al.—has been a mainstay of pros, especially photojournalists, since the early 1990s. This range is ideal for sweeping views and tight quarters, and is easily handheld. The 17-40L is a favorite wide zoom for landscape shooting on full frame, e.g., 5D MKII and 6D. If you use a 1.6X cropped frame camera, e.g., Rebel, 60D, 70D, etc., this zoom will have the field of view of a normal zoom, i.e., 28-65mm equivalent.

Venetian Ceiling | EOS 10D, EF 17-40 4L USM and 430EX Speedlite.

This review consists of my opinions and observations as a hobbyist. No scientific measurements, MFT charts or pixel peeking comparisons will be found here.

Compatibility

The EF 17-40 4L USM lens works on all Canon EOS SLR and DSLR cameras, both full frame and APS-C (1.6X), such as the EOS 6D and Rebel SL3. It will also work on EOS R and M series mirrorless cameras with a mount adapter. It does not fit FD mount and non-Canon cameras such as Pentax, Nikon, Fuji, etc.

Last Light | Honolulu | EOS 10D, EF 17-40 4L USM, 40mm, F8, 1/400, ISO 200

Construction

Canon's EF 17-40 4L USM brings together precision optical design, fast AF, durable construction and smooth zoom and focus rings. At about $750 new, it's more affordable than the EF 16-35 2.8L USM II and EF 16-35 4L IS USM, but offers similar build and optical quality. The hybrid metal and polycarbonate construction and quality components make the EF 17-40 4L USM tough as nails, but still a lightweight 475 g (16.8 oz.). Plus, moisture and dust seals and an O-ring on the lens mount make it a great choice for jungle and beach shooters. Canon recommends use of a clear or UV filter to complete weather sealing (front element moves slightly during zoom).

EF 17-40 4L USM | Photo courtesy Canon Inc.

The EF 17-40 4L USM is a classic two-touch design: manual focus ring near the end of the barrel and zoom ring near the mount. Handling is nimble and decisive. Both zoom and focus mechanisms are internal so there is no extension or nested barrels. Plus, internal mechanisms are less prone to sucking in dust than front extension designs. Unlike most AF lenses, the manual focus ring is large, ribbed, rubberized and nearly as smooth turning as the manual lenses of yesteryear. The satin black finish is elegant and the overall appearance similar to the EF 16-35 2.8 USM II and EF 24-105 4L IS USM.

Ballys | Las Vegas, NV | EOS 10D and EF 17-40 4L USM

The filter size is 77 mm, making filters large and expensive. The clearance from the front element edge to the filter threads is huge and, subsequently, normal thickness filters such as a Hoya Super HMC UV do not vignette even on full frame cameras like the 5D MKII or 6D. Don't use an extra slim filter on this lens as the reduced thickness may cause the filter to come in contact with the front element during zoom operation (front element moves slightly).

Vista House | Columbia Gorge, Oregon | EOS 50D, EF 17-40 4L USM, F4, 17mm, 1/30, ISO 160

Auto Focus

This lens features ring-type USM (Ultrasonic Motor) driving an internal lens group. The front element does not rotate nor does the barrel expand or contract during focus and zoom operations. The motor of the EF 17-40 4L USM is silent during AF. It has Full Time Manual (FTM), allowing you to manually focus without switching out of AF mode. If you prefocus manually, the distance window in meters and feet is useful. AF proved to be fast, accurate and decisive on my 6D, 5D MKII, 5D, 10D, 20D, 40D and Elan 7E.

New York New York | Las Vegas, NV | EOS 20D, EF 17-40 4L USM, F4

Image Quality

I mainly used the EF 17-40 4L USM on the EOS 10D, 20D, and 40D—APS-C cameras with 6 to 10MP sensors! And image quality was amazingly sharp and contrasty across the zoom range from F4 to F11.

When I finally got a full-frame camera, the 12MP EOS 5D, the EF 17-40 4L USM was still very good: sharp and contrasty in the center and mid-frame across the zoom range. However, the periphery was soft at 17mm and only improved slightly when stopped to F8 or more. From 24mm onwards, the periphery was sharp at F4 and became even sharper as stopped down. If you're a landscape shooter living at F8, this is a great lens. If you mainly shoot wide open on a full-frame camera, know that the edges and corners are soft from 17 to about 20mm. In practice, I rarely noticed edge and corner softness at 17mm and F4 since backgrounds were usually defocused and darker than the subject.

Aloha Tower | Honolulu, HI | EOS 10D, EF 17-40 4L USM, 24mm, F4, 1/30, ISO 800 and Speedlite 430 EX

Flare and coma are well controlled for a zoom lens. However, some ghosting may occur with bright sunsets. Use the included lens shade (EW-83E) to protect the lens and help keep flare in check. Incidentally, the included EW-83E is a poor design: too shallow and dish-like, yielding a minimal amount of protection. The EW-83H, a deeper and narrower hood intended for the EF 24-105 4L IS USM, gives much better protection and does not vignette at any zoom setting on both full-frame and cropped cameras. 

The short end, like most wide zooms, shows some barrel distortion. The long end has a small amount of pincushion distortion. Distortion is easily corrected using the lens profile in an editing program like Canon DPP4 or Adobe Lightroom.

Vega Strip | EOS 20D, EF 17-40 4L USM, 40mm, F4, 1/30, ISO 800

Last Blurb

I bought the 17-40 4L in 2003, mainly serving as my travel lens on APS-C. After two decades of beaches, waterfalls, jungles, and deserts, and it's still going strong, outliving most of my cameras. It's still a great lens in 2026, but obviously not up to the edge standards of an EF 16-35 4L IS USM or RF 14-35 4L IS USM. Today, people tend to buy the 17-40 4L if their budget is tight or they merely need a battle-grade wide zoom for occasional use. Used EF 17-40L USM often go for a couple of Benjamins, so it’s currently a great deal for this legendary optic of yesteryear.

Frary Guitar Duo | EOS 20D, EF 17-40 4L USM, 430EX, 420EX and ST-E2

Features and Specs

• Focal Length: 17-40 mm
• Aperture: F4 to 22
• Lens Construction: 12 elements in 9 groups with 1 UD and 2 aspherical elements
• Auto Focus: Ring-USM with internal focus
• Min. Focusing Distance: .28 m /. 92 ft.
• Included Accessories: EW-83E Lens Hood and Storage Bag

• Diameter and Length: 83.5 x 96.8 mm / 3.3 x 3.8 inches
• Weight: 475 g / 16.8 oz.

Image Samples

 1/17/2004 | Updated 10/24/2026