Canon RF 100-400mm f5.6-8 IS USM Lens

The Canon RF 100-400mm f/5.6-8 IS USM is a full-frame telephoto zoom lens designed to provide extended reach and solid performance in a compact, affordable package for Canon EOS R series mirrorless cameras. Its 100–400 mm zoom range covers a broad span of telephoto needs — from moderate telephoto frames to long-reach shots — making it a flexible choice for wildlife, sports, travel, and outdoor photography.

Optical Design & Performance
The lens incorporates 12 optical elements in 9 groups, including an Ultra-Low Dispersion (UD) element and an aspherical element to suppress chromatic aberrations and maintain clarity across the zoom range. A 9-blade circular diaphragm contributes to pleasing out-of-focus rendering (bokeh) when shooting subjects isolated from their background.

Autofocus & Handling
Equipped with Canon’s Nano USM (Ultrasonic Motor), this lens delivers fast, smooth, and relatively quiet autofocus for both still imagery and video capture. A rear focusing system helps keep focus transitions responsive throughout the zoom range.

Image Stabilization
The built-in Optical Image Stabilizer (IS) offers up to approximately 5.5 stops of shake correction when used handheld, and — when paired with an EOS R camera that has in-body image stabilization (IBIS) — coordinated IS can achieve up to about 6 stops of correction for steadier shooting in low light or at long focal lengths.

Close-Focus & Magnification
At the telephoto end (400 mm), the lens offers a maximum magnification of about 0.41× and a minimum focus distance of approximately 0.88 m (at mid-range), enabling semi-close-up captures of subjects like flowers, small animals, or detail regions of distant objects.

Extender Compatibility
This lens is also compatible with Canon RF 1.4× and RF 2× tele extenders, which extend the effective reach to 560 mm or up to 800 mm, respectively — a unique feature for a non-L-series telephoto zoom and useful for wildlife or sports requiring even greater magnification.

Portability & Build
At approximately 635 g and ~164.7 mm in length, the RF 100-400mm f/5.6-8 IS USM is comparatively compact and lightweight for its reach, making it comfortable to carry on longer shoots or when traveling. It features a metal RF mount, though it lacks professional weather sealing found on higher-end L lenses.

Key Specifications

• Focal Length: 100–400 mm

• Maximum Aperture: f/5.6–8 (variable)

• Minimum Aperture: f/32–45

• Lens Mount: Canon RF

• Optical Construction: 12 elements in 9 groups (1 UD, 1 aspherical)

• Autofocus: Nano USM with rear focusing

• Image Stabilization: Up to ~5.5 stops (optical) / ~6 stops (coordinated with IBIS)

• Minimum Focus Distance: ~0.88 m @ ~200 mm

• Maximum Magnification: ~0.41× @ 400 mm

• Filter Thread: 67 mm

• Diaphragm Blades: 9 (circular)

• Dimensions: ~Ø79.5 × 164.7 mm

• Weight: ~635 g

• Extender Compatibility: RF 1.4× / RF 2×

Who It’s For

The Canon RF 100-400mm f/5.6-8 IS USM is particularly well-suited to:

• Wildlife and nature photography where long reach is needed without heavy gear.

• Sports and action shooting in good light conditions.

• Travel and handheld telephoto photography thanks to its compact, lightweight build.

• Hybrid photo/video creators who benefit from smooth Nano USM focus and image stabilization.

• Telephoto flexibility with extenders for greater reach without sacrificing native mount performance.