Standard prime · Full frame

Canon EF 40mm f/2.8 STM

The Canon EF 40mm f/2.8 STM is a full frame prime lens (40 mm, f/2.8) for Canon EF. It belongs to the standard prime class — ideal for street, documentary, everyday and low-light shooting.

40 mmf/2.8Canon EF
40 mm
Focal length
f/2.8
Maximum aperture
57°
Diagonal angle of view (Full frame)
Full frame
Designed for

Specifications#

Brand
Canon
Model
EF 40mm f/2.8 STM
Lens type
Standard prime
Focal length
40 mm
Maximum aperture
f/2.8
Image circle
Full frame (36×24 mm)
Mount(s)
Canon EF
Projection
Rectilinear
Autofocus motor
stepping motor (STM)
Lensfun correction profile
Yes — distortion/vignetting/TCA

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 formatAt 40 mmEquiv. aperture (DoF)
Full frame40 mm · 57°f/2.8
APS-C60 mm · 39°f/4.2
APS-C (Canon)64 mm · 37°f/4.5
Micro Four Thirds80 mm · 30°f/5.6

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: 40 mm f/2.8 on full frame.

FocalApertureat 1 mat 2 mat 5 mat 10 mHyperfocalBlur @2 m
40 mmf/2.810.1 cm41.6 cm2.79 m14.4 m19.1 m0.8%
40 mmf/414.5 cm60.1 cm4.32 m33.8 m13.4 m0.6%
40 mmf/829.4 cm1.29 m16.7 m∞6.71 m0.3%

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).

BodyMin. handheld shutter (longest focal)500 rule at 40 mmNPF at 40 mm, f/2.8
Full frame1/40 s12 s7 s
APS-C1/60 s8 s5 s
APS-C (Canon)1/60 s8 s5 s
Micro Four Thirds1/80 s6 s5 s

Compatible cameras#

Bodies in our database with a native Canon EF mount.

Adapt it to other systems#

Sony E-mountCanon RFNikon ZFujifilm X-mountMicro Four ThirdsL-MountCanon EF-MFujifilm G-mountHasselblad XCDNikon 1 (CX)Pentax QSamsung NXNikon FPentax K

Similar lenses#

Frequently asked questions#

Is the Canon EF 40mm f/2.8 STM full frame?

Yes — it covers the full 36 × 24 mm frame.

What is the Canon EF 40mm f/2.8 STM equivalent to on APS-C?

On a 1.5× APS-C body it frames like 60 mm, and like 64 mm on Canon APS-C.

What is the Canon EF 40mm f/2.8 STM good for?

As a standard prime it suits street, documentary, everyday and low-light shooting.

Sources & licences#

Last updated October 03, 2026 · How we calculate · Sources