Specifications#
Equivalent focal length on different cameras#
Field of view and depth-of-field equivalence when this lens is used on bodies with different sensor sizes (natively or via an adapter).
| Camera format | At 17 mm | At 26 mm | At 40 mm | Equiv. aperture (DoF) |
|---|---|---|---|---|
| Full frame | 17 mm · 104° | 26 mm · 80° | 40 mm · 57° | f/4.0 |
| APS-C | 26 mm · 79° | 39 mm · 57° | 60 mm · 39° | f/6.0 |
| APS-C (Canon) | 27 mm · 77° | 42 mm · 55° | 64 mm · 37° | f/6.4 |
| Micro Four Thirds | 34 mm · 65° | 52 mm · 45° | 80 mm · 30° | f/8.0 |
Depth of field & background blur#
Computed on its native Full frame format (CoC 30 µm). “Blur @2 m” is the size of an out-of-focus point at infinity, as a percentage of frame width, with the subject at 2 m — a simple bokeh index. Full table: 16 mm f/4 on full frame.
| Focal | Aperture | at 1 m | at 2 m | at 5 m | at 10 m | Hyperfocal | Blur @2 m |
|---|---|---|---|---|---|---|---|
| 17 mm | f/4 | 98.0 cm | 10.2 m | ∞ | ∞ | 2.43 m | 0.1% |
| 17 mm | f/8 | 4.89 m | ∞ | ∞ | ∞ | 1.22 m | 0.1% |
| 26 mm | f/4 | 35.6 cm | 1.60 m | 40.1 m | ∞ | 5.66 m | 0.2% |
| 26 mm | f/8 | 78.6 cm | 5.51 m | ∞ | ∞ | 2.84 m | 0.1% |
| 40 mm | f/4 | 14.5 cm | 60.1 cm | 4.32 m | 33.8 m | 13.4 m | 0.6% |
| 40 mm | f/8 | 29.4 cm | 1.29 m | 16.7 m | ∞ | 6.71 m | 0.3% |
Handheld & night-sky limits#
NPF assumes typical 20–24 MP sensors (≈6 µm pixels on full frame, ≈3.9 µm on APS-C, ≈3.3 µm on Micro Four Thirds).
| Body | Min. handheld shutter (longest focal) | 500 rule at 17 mm | NPF at 17 mm, f/4 |
|---|---|---|---|
| Full frame | 1/40 s | 29 s | 19 s |
| APS-C | 1/60 s | 20 s | 15 s |
| APS-C (Canon) | 1/60 s | 18 s | 15 s |
| Micro Four Thirds | 1/80 s | 15 s | 14 s |
Compatible cameras#
Bodies in our database with a native Canon EF mount.
- Canon EOS-1D X Mark III 2020
- Canon EOS 6D Mark II 2017
- Canon EOS 5D Mark IV 2016
- Canon EOS-1D X Mark II 2016
- Canon EOS 5DS 2015
- Canon EOS 5DS R 2015
- Blackmagic Design Pocket Cinema Camera 2013
- Canon EOS 5D Mark III 2012
- Canon EOS 6D 2012
- Canon EOS-1D X 2012
- Canon EOS-1D C 2012
- Canon EOS-1D Mark IV 2009
- Canon EOS 5D Mark II 2008
- Canon EOS-1Ds Mark III 2007
- Canon EOS-1D Mark III 2007
- Canon EOS 5D 2005
- Canon EOS-1Ds Mark II 2004
- Kodak DCS Pro SLR/c 2004
- Canon EOS-1D Mark II 2004
- Canon EOS 30V 2004
- Canon EOS-1Ds 2002
- Canon EOS 3000N 2002
- Canon EOS 300V 2002
- Canon EOS-1D 2001
- Canon EOS-1V 2000
- Canon EOS 30 2000
- Canon EOS D2000 1998
- Canon EOS-3 1998
- Canon EOS 500N 1996
- Canon EOS IX 1996
- Canon EOS 50 1995
- Canon EOS-1N 1994
- Canon EOS 500 1993
- Canon EOS 5 1992
- Canon EF-M camera 1991
- Canon EOS 100 1991
- Canon EOS 1000 1990
- Canon EOS-1 1989
- Canon EOS 650 1987
- Canon EOS C300
Adapt it to other systems#
Similar lenses#
- Canon EF 17-35mm f/2.8L USM f/2.8
- Sigma 17-35mm F2.8-4 EX DG Aspherical HSM f/2.8–4
- Sigma 17-35mm f/2.8-4 EX DG f/2.8–4
- Tamron 17-35mm f/2.8-4 Di OSD (A037) f/2.8–4
- Tamron SP AF 17-35mm f/2.8-4 Di LD Aspherical (IF) f/2.8–4
- Canon EF 16-35mm f/4L IS USM f/4
- Canon EF 16-35mm f/2.8L II USM f/2.8
- Canon EF 16-35mm f/2.8L III USM f/2.8
- Canon EF 16-35mm f/2.8L USM f/2.8
- Tokina AF 16-28mm f/2.8 AT-X Pro SD FX f/2.8
- Tamron AF 19-35mm f/3.5-4.5 f/3.5–4.5
- Tokina AF 19-35mm f/3.5-4.5 f/3.5–4.5
Frequently asked questions#
Is the Canon EF 17-40mm f/4L USM full frame?
Yes — it covers the full 36 × 24 mm frame.
What is the Canon EF 17-40mm f/4L USM equivalent to on APS-C?
On a 1.5× APS-C body it frames like 26–60 mm, and like 27–64 mm on Canon APS-C.
What is the Canon EF 17-40mm f/4L USM good for?
As a wide-angle zoom it suits landscapes, architecture, interiors and astrophotography.
Sources & licences#
- Lensfun lens database — CC BY-SA 3.0
Last updated October 03, 2026 · How we calculate · Sources