Spanning a versatile wide-angle range, the EF 17-40mm f/4L USM Lens is a Canon L-series zoom featuring a constant f/4 maximum aperture along with a sophisticated optical design and durable construction. One Super UD element is featured, along with three aspherical elements, which help to reduce both chromatic and spherical aberrations in order to realize high sharpness, clarity, and color accuracy. A Super Spectra coating has also been applied to suppress flare and ghosting for improved contrast in difficult lighting conditions. Complementing the imaging capabilities, this wide-angle zoom also features a ring-type USM and internal focusing mechanism to afford quick, quiet, and accurate autofocus performance, as well as full-time manual focus override. Additionally, this lens is weather-sealed for use in trying environmental conditions.

EF-Mount Lens/Full-Frame Format    Aperture Range: f/4 to f/22    One Super Ultra-Low Dispersion Element    Three Aspherical Element    Super Spectra Coating    Ring-Type Ultrasonic Motor AF System    Weather-Sealed Construction    Rounded 7-Blade Diaphragm

Wide-angle zoom is designed for full-frame Canon EF-mount DSLRs, however can also be used with APS-C models where it provides a 27.2-64mm equivalent focal length range.

Constant f/4 maximum aperture maintains consistent illumination throughout the zoom range.

One Super Ultra-Low Dispersion glass element noticeably reduces color fringing and chromatic aberrations for high clarity and color fidelity.

Three aspherical elements minimize spherical aberrations and distortions for improved sharpness and accurate rendering.

Super Spectra coating has been applied to individual elements to minimize ghosting and flare for greater contrast and color neutrality when working in strong lighting conditions.

A ring-type Ultrasonic Motor (USM), along with an internal focusing system, is employed to deliver fast, precise, and quiet autofocus performance as well as full-time manual focus override.

Rounded seven-blade diaphragm contributes to a pleasing out of focus quality that benefits the use of shallow depth of field and selective focus techniques.

As a member of the esteemed L-series, this lens is sealed against dust and moisture for working in inclement environmental conditions.

In addition to the front 77mm filter ring, this lens also has a rear filter holder for up to three cut gel filters.

Related Questions and Answers

Q: 1. Would this lens work with a Mitakon Zhongyi turbo II lens adapter attached to a Blackmagic pocket cinema camera? Can I control the focus, and the aperture? Thanks.

A: It appears that the Mitakon Zhongyi turbo II lens adapter is a manual adapter, which means there would be no electronic communication between the lens and the camera. You would not be able to adjust the lenss aperture, and you would need to focus manually.

Q: 2. is this lens compatible with canon t5i?

A: Yes. The t5i is compatible with EF (full framed) lenses.

Q: 3. I use a Canon 6D, and I'm considering buying this lens. I'm a bit concerned with the fact that it only opens up to f/4. Should I be concerned? Or would ISO be able to make up for it without reducing image quality?

A: I have the 6D and the 17-40mm f/4L lens and they work great together. The full frame sensor in the 6D lets you crank up the ISO without adding too much noise and the noise reduction features in Adobe Lightroom virtually eliminate any noise that is present. I routinely shoot indoors in low light with no flash and have had no trouble. I switched to the 6D 2 years ago and it took a little while to get used to the fact that I could crank up the ISO to 12000+ and still get great images.

Q: 4. The canon site states this lens can be used with the extender 1.4x and 2.0x is this correct?Pete

A: Teleconverters are not compatible with lenses with a focal length wider than 70mm, including the Canon EF 17-40mm f/4L. The Canon website specifies that this lens can be used with extenders, meaning extension tubes. Those extension tubes are the Extension Tube EF 12 II http://bhpho.to/VMSt9k and the EF 25 II: http://bhpho.to/1tyEhgB

Q: 5. i have cankn 5d mark iv. knowing this is a older lens, how will the quality be.

A: The 17-40mm lens is very good image quality and will work quite well on the 5DIV.

Q: 6. Is this a good zoom lens for shooting in limited light, such as an auditorium or in a theater without a flash?

A: I would recommend purchasing the brightest lens possible for your stated usage needs. Of the options we carry with a similar focal length and which would be compatible for use on the Canon EOS Digital Rebel T5i DSLR camera, I would recommend the Sigma 18-35mm f/1.8 DC HSM Art Lens for Canon EF, B&H # SI183518DCC, for your usage needs. The constant f/1.8 aperture is 2.3 f-stops brighter than the f/4 aperture used on the Canon EF 17-40mm f/4L USM Lens. As an example, if your shooting conditions require you to have an exposure of f/4 at 1/13 sec. to get a properly exposed image, and there is a chance you can get blurred images due to a slow shutter speed, the Sigma lens would give you the ability to shoot an equivalent exposure of f/1.8 at 1/60 sec., which is much faster to hand-hold this lens at any of its focal lengths with minimum blur from hand movement. You may further use a higher ISO setting to assist in obtaining an exposure with a shutter speed fast enough for your specific lighting conditions. However, do note that the lighting conditions you list above are extreme, so you may need a higher-than-normal ISO setting, and which is why the brighter Sigma 18-35mm f/1.8 DC HSM Art Lens for Canon EF would be a better option for your indicated usage needs.

Q: 7. I have the cropped sensor canon 77d, and Im not sure which L series lens to choose from for landscape photography? planning on using it at Yosemite and more.

A: The Canon EF 17-40mm f/4L USM Lens listed above is not much wider than the Canon EF-S 18-55mm f/4-5.6 IS STM Lens or the Canon EF-S 18-135mm f/3.5-5.6 IS USM Lens originally included as kit lenses with the purchase of the Canon EOS 77D DSLR Camera. If you are specifically looking for an L-series lens for landscape photography and need the lens wider than your current lens, I would recommend the Canon EF 11-24mm f/4L USM Lens B&H # CA11244LUSM, for your usage needs. If you need a more economically-priced lens option, while it is not a Canon L-series lens, the Sigma 12-24mm f/4 DG HSM Art Lens for Canon EF, B&H # SI12244C, would also be a good full-frame lens option compatible for use on the Canon EOS 77D DSLR camera.

Q: 8. Will this fit a canon eos 80D?

A: I use this lens all the time on my 6D, 5D Mk III which are both full frame camera's. I also use it with my Canon 60D not a full frame camera, but indeed get great images. You can't go wrong with your choice!

Q: 9. Can I use it on my 6d?

A: Yes

Q: 10. Will I be able to use a filter on the lens ?

A: Yes, but I've only been able to use one at a time. More than that and I start to see the edge of the filter when shooting at 17mm.