The Canon EF 17-40mm f/4L and the EF 16-35mm L lenses are both full-frame wide-angle zooms, but the 16-35 comes in several versions with different apertures and designs. In general, the 16-35 reaches a little wider and often offers a brighter aperture, while the 17-40 is the simpler, lighter, f/4 choice.

Canon 17-40mm vs 16-35mm: Choosing a Wide-Angle L Zoom

What Each Lens Is For

Both lenses suit landscapes, architecture, real estate, travel, and group scenes in tight spaces. The 17-40mm f/4L is a single model with a constant f/4 aperture. The 16-35mm name covers more than one generation, including f/2.8 models and an f/4 model with image stabilization, so you need to know exactly which version you are looking at.

Key Differences

  • Width: One millimeter sounds small, but 16mm is noticeably wider than 17mm, which matters in cramped rooms and for dramatic foreground compositions.
  • Aperture: The 17-40 is f/4. Some 16-35 versions are f/2.8, which helps in dim light, and one version is f/4 with stabilization.
  • Size: The 17-40 is generally lighter and more compact than the f/2.8 versions of the 16-35.
  • Edge performance: Newer 16-35 designs are generally regarded as stronger toward the corners, while the 17-40 is an older design. Check sample images for the exact version you want.
  • Availability: The 17-40 is a common used lens. The 16-35 varies depending on the generation.

How to Choose Between Them

  1. Decide whether 16mm versus 17mm changes your framing. Interior and architecture shooters often notice it.
  2. Decide whether you need f/2.8. Astro and event shooters often do; landscape shooters often do not.
  3. Decide whether stabilization matters. Only the f/4 IS version of the 16-35 offers it, and it helps with handheld stills at slower shutter speeds.
  4. Match the lens to your body. All are EF mount, so mirrorless owners need an adapter or should consider a native RF wide zoom.
  5. Confirm filter size and compatibility with the filters you already own.

Things to Know About Used Copies

Because these lenses have been around for years, many are sold used. Look for clean glass, smooth zoom and focus rings, and no wobble in the barrel. Try a few frames at both ends of the zoom, because decentering can show up as one soft side of the image.

FAQ

Which is better for landscapes, the 17-40 or the 16-35?

Either works. The extra width and corner sharpness of newer 16-35 versions can help, but the 17-40 is a capable, lighter choice that many landscape shooters have used for years.

Is the 16-35 always f/2.8?

No. There are f/2.8 versions and an f/4 version with image stabilization. Check the exact model name on the lens or the listing.

The Short Version

Choose the 17-40mm f/4L if you want a lighter, simple wide zoom for daylight work. Choose a 16-35mm if you want extra width, a brighter aperture, or stabilization, and confirm which version it is. Verify the details on the maker’s page before you commit.