RF 100–400mm F5.6–8 IS USM

Released October 2021

A compact full-frame RF telephoto zoom with Nano USM autofocus, optical image stabilisation and RF extender compatibility.

Mount: Canon RF
Focal length: 100–400 mm
Max aperture: f/5.6–8
Stabilisation: Yes
Weight: 635 g

What reviewers say

Both reviews praise portability, value and fast quiet autofocus, while noting the slow aperture and absent weather sealing. Cameralabs finds sharp results across the frame and effective wildlife tracking. OpticalLimits is less positive about long-end corners and background blur. Both find useful stabilisation but advise against assuming the full claimed benefit in everyday shooting.

From opticallimits.com, cameralabs.com and cameralabs.com

Specifications

Report a wrong or missing spec

Optics

Lens type: Zoom
Focal length: 100–400 mm
Maximum aperture: f/5.6–8
Minimum aperture: f/32–45
Optical construction: 12 elements in nine groups
Special elements: One UD element and one PMo aspherical element
Coatings: Super Spectra; no fluorine coating, per UK maker table
Diaphragm: Nine blades

Mount and compatibility

Mounts: Canon RF
Image circle: Full frame
Compatibility: Canon RF mount, full-frame image circle; incompatible with EF DSLRs and EOS M cameras
Teleconverter support: RF1.4× gives 140–560 mm f/8–11 and maximum 0.58×; RF2× gives 200–800 mm f/11–16 and maximum 0.83×. Maker confirms autofocus and IS, with reduced AF coverage on listed EOS R bodies; extenders usable throughout the zoom range

Focus and stabilisation

Autofocus: Yes
Minimum focus distance: 0.88 m
Maximum magnification: 0.41×
Optical stabilisation: Yes
Autofocus detail: Nano USM autofocus and electronic manual focus
Focus distance detail: Maker minimum focus 1.2 m at 100 mm, 0.88 m at 200 mm, 0.95 m at 300 mm and 1.05 m at 400 mm. Main value is the closest published distance at 200 mm; Cameralabs’ approximate constant-distance observation does not replace the maker’s per-focal-length table
Magnification detail: 0.09× at 100 mm, 0.24× at 200 mm, 0.34× at 300 mm and 0.41× at 400 mm; no unpublished AF/MF distinction inferred
Stabilisation detail: Optical IS rated 5.5 stops at 400 mm on EOS R under CIPA, yaw/pitch; coordinated EOS R5 body/lens IS rated six stops under the same maker conditions. Cameralabs measured approximately five stops at 100 mm and three at 400 mm with EOS R6, a different test condition
Video features: Cameralabs found little focus breathing and mostly maintained focus while zooming in its tests; these are reviewer observations rather than maker parfocal certification

Design

Dust and moisture resistant: No
Filter diameter: 67 mm
Maximum diameter: 79.5 mm
Length: 164.7 mm
Weight: 635 g
Controls: Separate zoom, electronic manual focus and custom control rings; AF/MF and IS switches; zoom lock
Zoom design: Extending zoom barrel; main maker length measured retracted
Weather resistance: UK maker specification explicitly states no dust/moisture resistance
Dimensions detail: Approximately 79.5 mm maximum diameter × 164.7 mm length when retracted
Weight detail: Approximately 635 g lens
Lens hood: ET-74B, optional accessory
Release detail: October 2021 marketed month in Canon Camera Museum, matching Canon Canada’s original October availability. No exact worldwide first-sale day inferred; no direct replacement of brighter EF or RF L-series zooms assumed

Pros and cons

Pros

635 g lens weight
Optical image stabilisation
RF extenders work throughout the zoom range

Cons

f/8 maximum aperture at 400 mm
No weather resistant construction
Hood sold separately

Closest rivals

Model	Mount	Focal length	Max aperture	Stabilisation	Weight	Released
CanonRF 100–500mm F4.5–7.1L IS USM	Canon RF	100–500 mm	f/4.5–7.1	Yes	1,370 g	Aug 2020
CanonRF 75–300mm F4–5.6	Canon RF	75–300 mm	f/4–5.6	No	507 g	May 2025
CanonRF 100–300mm F2.8L IS USM	Canon RF	100–300 mm	f/2.8	Yes	2,590 g	May 2023

Sources

Photo: Canon Asia Photo Library; official press archive member RF100-400mm f5.6-8 IS USM Slant.jpg; complete supplied canvas and white background retained.

Side profile of the Canon RF100-400mm F5.6-8 IS USM lens: personal.canon.jp/-/media/Project/Canon/CanonJP/Personal/product/camera/rf/rf10…
Diagonal three-quarter view of the Canon RF100-400mm F5.6-8 IS USM lens: global.canon/ja/c-museum/wp-content/uploads/2022/09/rf511_b.jpg
Canon RF100-400mm F5.6-8 IS USM Extended, official press photograph: Canon Asia Photo Library; official press archive member RF100-400mm f5.6-8 IS USM Extended.jpg; complete supplied canvas and white background retained.

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