Canon RF 10-20mm f/4L IS STM Specs, Equivalents & Depth of Field

10–20 mm

Focal length

f/4

Maximum aperture

130°–94°

Diagonal angle of view (Full frame)

Full frame

Designed for

2.0×

Zoom ratio

Specifications#

Brand: Canon
Model: RF 10-20mm f/4L IS STM
Lens type: Wide-angle zoom
Focal length: 10–20 mm
Maximum aperture: f/4
Image circle: Full frame (36×24 mm)
Mount(s): Canon RF
Projection: Rectilinear
Stabilisation: Yes (optical)
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 format	At 10 mm	At 14 mm	At 20 mm	Equiv. aperture (DoF)
Full frame	10 mm · 130°	14 mm · 114°	20 mm · 94°	f/4.0
APS-C	15 mm · 109°	21 mm · 90°	30 mm · 70°	f/6.0
APS-C (Canon)	16 mm · 107°	22 mm · 88°	32 mm · 68°	f/6.4
Micro Four Thirds	20 mm · 95°	28 mm · 75°	40 mm · 57°	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: 14 mm f/4 on full frame.

Focal	Aperture	at 1 m	at 2 m	at 5 m	at 10 m	Hyperfocal	Blur @2 m
10 mm	f/4	∞	∞	∞	∞	84.3 cm	0.0%
10 mm	f/8	∞	∞	∞	∞	42.7 cm	0.0%
14 mm	f/4	1.90 m	∞	∞	∞	1.65 m	0.1%
14 mm	f/8	∞	∞	∞	∞	83.1 cm	0.0%
20 mm	f/4	64.4 cm	3.67 m	∞	∞	3.35 m	0.1%
20 mm	f/8	1.80 m	∞	∞	∞	1.69 m	0.1%

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 10 mm	NPF at 10 mm, f/4
Full frame	1/20 s	50 s	32 s
APS-C	1/30 s	33 s	26 s
APS-C (Canon)	1/30 s	31 s	25 s
Micro Four Thirds	1/40 s	25 s	24 s

Compatible cameras#

Bodies in our database with a native Canon RF mount.

Adapt it to other systems#

Sony E-mount Nikon Z Fujifilm X-mount Canon EF-M Hasselblad XCD Nikon 1 (CX)Pentax Q

Similar lenses#

Canon RF-S 10-18mm F4.5-6.3 IS STM f/4.5–6.3
Sigma 10-18mm F2.8 DC DN | Contemporary 023 f/2.8
Tamron 11-20mm f/2.8 Di III-A RXD (B060) f/2.8
Canon RF 14-35mm F4 L IS USM f/4
Canon RF 15-30mm F4.5-6.3 IS STM f/4.5–6.3
Canon RF 15-35mm F2.8L IS USM f/2.8

Frequently asked questions#

Is the Canon RF 10-20mm f/4L IS STM full frame?

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

What is the Canon RF 10-20mm f/4L IS STM equivalent to on APS-C?

On a 1.5× APS-C body it frames like 15–30 mm, and like 16–32 mm on Canon APS-C.

What is the Canon RF 10-20mm f/4L IS STM 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