Canon EF 100-400mm Review

Released in 2014, the Canon EF 100-400mm f/4.5-5.6L IS II USM was the long-awaited successor to the original push-pull zoom version. This second-generation lens brought major improvements in optical quality, image stabilisation, and usability, making it a favourite among wildlife, sports, and aviation photographers. It delivers the reach of a super-telephoto lens while remaining compact enough for travel, earning a reputation as one of the most versatile zooms in Canon’s L-series lineup.

Build and Design

As an L-series lens, the 100-400mm f/4.5-5.6L IS II USM is built with magnesium alloy construction, ensuring durability without excessive weight. Weighing in at 1,570g, it is lighter than many prime telephotos but still substantial enough to feel robust. The lens is fully weather-sealed, with dust and moisture resistance, making it ideal for shooting in harsh environments.

Unlike its predecessor, which used a push-pull zoom mechanism, this version employs a rotary zoom design, which provides smoother and more precise control. However, Canon retained a zoom tension ring, allowing photographers to adjust how easily the zoom moves—handy for avoiding lens creep when carrying it around.

The built-in rotating tripod collar is another thoughtful addition, making it easy to transition between landscape and portrait orientation when mounted on a tripod or monopod. It accepts 77mm filters, a common size across Canon’s L-series lenses.

Optical Performance

This lens is razor-sharp across the entire zoom range, with excellent contrast and colour rendition. Thanks to Canon’s Air Sphere Coating (ASC), it significantly reduces flare and ghosting, making it a fantastic choice for backlit and high-contrast scenes.

The lens incorporates one fluorite and one Super UD (Ultra-low Dispersion) element, which effectively minimises chromatic aberrations. This results in exceptional detail and clarity, even when shooting at 400mm wide open at f/5.6.

Bokeh is surprisingly good for a zoom of this type. The nine-blade aperture diaphragm creates a smooth background blur, making it possible to isolate subjects effectively, particularly at the longer focal lengths.

Autofocus Performance

Equipped with Canon’s ring-type USM (Ultrasonic Motor) and an internal focusing system, the autofocus is fast, silent, and highly accurate. Even in low-light conditions, the lens locks onto subjects quickly, making it perfect for fast-moving wildlife and sports photography.

The focus limiter switch (3m–∞ or full range) helps speed up focus acquisition when shooting distant subjects, reducing hunting. This is particularly useful for bird photography, where quick reaction times are crucial.

Image Stabilisation

One of the standout features of this lens is its advanced four-stop Image Stabilisation (IS) system, which offers three distinct modes:

Mode 1: General stabilisation for static subjects.
Mode 2: Panning stabilisation, ideal for motorsports and wildlife tracking.
Mode 3: Activates stabilisation only at the moment of exposure, useful for unpredictable motion.

This makes handheld shooting at long focal lengths far more manageable, even in lower light conditions. Compared to the original 100-400mm, the IS in this version is significantly improved, allowing for sharp images at slower shutter speeds.

Handling and Versatility

One of the biggest strengths of this lens is its versatility. With a 100-400mm range, it covers everything from portraits and environmental shots to tightly framed wildlife images. This flexibility makes it an excellent all-in-one telephoto option for those who don’t want to carry multiple lenses.

For even more reach, it is compatible with Canon’s 1.4x Extender, turning it into a 140-560mm f/6.3-8 lens. On cameras with f/8 autofocus support, such as the Canon 5D Mark IV and 1D X series, autofocus remains functional, though slightly slower.

The ability to handhold this lens, thanks to effective stabilisation and manageable weight, makes it ideal for travel and adventure photography.

Drawbacks

Variable aperture – The f/4.5-5.6 aperture limits low-light performance compared to f/4 or f/2.8 lenses.
Still relatively heavy – While lighter than prime super-telephotos, extended use can be tiring without support.
Extender limitations – Using a 1.4x extender reduces autofocus speed and limits usability in dim conditions.

Conclusion

The Canon EF 100-400mm f/4.5-5.6L IS II USM is one of the best zoom telephoto lenses in Canon’s EF lineup, offering exceptional sharpness, robust build quality, and advanced image stabilisation. It is a must-have for wildlife, sports, and aviation photographers, providing prime-like performance with the flexibility of a zoom.

For those needing a high-quality, portable super-telephoto solution, this lens delivers outstanding results. While newer RF-mount options exist for mirrorless users, this remains one of the finest EF telephoto zooms ever made, making it a fantastic investment for DSLR shooters.

Samples

Here are some recent photos I captured using the Canon EF 100-400mm f/4.5-5.6L IS II USM lens. These sample shots highlight the lens’s performance across different conditions, settings, and subjects. To view the complete collection of photos taken with this lens, the link.