Canon EF 300mm f/4L IS USM + 1.4× ext. Specs & DoF

300 mm

Focal length

f/4

Maximum aperture

8°

Diagonal angle of view (Full frame)

Full frame

Designed for

Specifications#

Brand: Canon
Model: EF 300mm f/4L IS USM + 1.4× ext.
Lens type: Telephoto prime
Focal length: 300 mm
Maximum aperture: f/4
Image circle: Full frame (36×24 mm)
Mount(s): Canon EF
Projection: Rectilinear
Stabilisation: Yes (optical)
Autofocus motor: ultrasonic (USM)
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 format	At 300 mm	Equiv. aperture (DoF)
Full frame	300 mm · 8°	f/4.0
APS-C	450 mm · 5°	f/6.0
APS-C (Canon)	480 mm · 5°	f/6.4
Micro Four Thirds	600 mm · 4°	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: 300 mm f/4 on full frame.

Focal	Aperture	at 1 m	at 2 m	at 5 m	at 10 m	Hyperfocal	Blur @2 m
300 mm	f/4	0.2 cm	0.9 cm	6.3 cm	25.9 cm	750 m	36.8%
300 mm	f/8	0.4 cm	1.8 cm	12.5 cm	51.8 cm	375 m	18.4%

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 300 mm	NPF at 300 mm, f/4
Full frame	1/320 s	2 s	1 s
APS-C	1/500 s	1 s	1 s
APS-C (Canon)	1/500 s	1 s	1 s
Micro Four Thirds	1/640 s	1 s	1 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#

Sony E-mount Canon RF Nikon Z Fujifilm X-mount Micro Four Thirds L-Mount Canon EF-M Fujifilm G-mount Hasselblad XCD Nikon 1 (CX)Pentax Q Samsung NX Nikon F Pentax K

Similar lenses#

Frequently asked questions#

Is the Canon EF 300mm f/4L IS USM + 1.4× ext. full frame?

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

What is the Canon EF 300mm f/4L IS USM + 1.4× ext. equivalent to on APS-C?

On a 1.5× APS-C body it frames like 450 mm, and like 480 mm on Canon APS-C.

What is the Canon EF 300mm f/4L IS USM + 1.4× ext. good for?

As a telephoto prime it suits sports, wildlife and stage photography.

Sources & licences#

Lensfun lens database — CC BY-SA 3.0