Released in late 2014, the Canon EF 100–400mm f/4.5–5.6L IS II USM is a professional-grade telephoto zoom lens designed for Canon’s full-frame and APS-C DSLR cameras. It builds upon the legacy of its predecessor—the original 100–400mm “push-pull” zoom—but incorporates a completely redesigned optical formula, improved handling, and enhanced image stabilization.
Intended for wildlife, sports, aviation, and outdoor action photography, this lens quickly became a favorite among enthusiasts and professionals alike due to its sharpness, versatility, and rugged build quality.
Key Specifications
Here are the core specs that define the 100–400mm f/4.5–5.6L IS II USM:
- Focal Length: 100–400mm
- Maximum Aperture: f/4.5–5.6
- Minimum Aperture: f/32–f/38
- Lens Construction: 21 elements in 16 groups
- Image Stabilization: 4-stop Optical Image Stabilizer (IS) with three modes
- Autofocus: Ring-type USM (Ultrasonic Motor) with full-time manual override
- Minimum Focus Distance: 0.98m (3.22 feet)
- Maximum Magnification: 0.31×
- Filter Size: 77mm
- Weight: Approximately 1,570g (3.46 lbs)
- Weather Sealing: Yes (dust and moisture resistant)
- Mount Compatibility: Canon EF mount (full-frame and APS-C)
Build Quality and Handling
As part of Canon’s L-series (Luxury) line, the 100–400mm Mark II is built to withstand the rigors of professional use. The body is constructed of high-grade metal and polycarbonate, offering a durable yet manageable form factor. A significant upgrade over the original model is the transition from a push-pull zoom to a rotating zoom ring, which is far more precise and offers better ergonomics.
The zoom action is smooth, and Canon cleverly includes a torque adjustment ring, allowing photographers to control how stiff or loose the zoom ring feels. This is especially handy in fast-paced situations like wildlife or motorsports, where accidentally zooming in or out can ruin a shot.
The lens features a removable tripod collar that is beautifully integrated into the lens barrel. It’s well-balanced and helpful when using the lens on a monopod or tripod for long shooting sessions.
Optical Quality
The 100–400mm f/4.5–5.6L IS II USM is regarded as one of the sharpest zoom lenses in its class. The optical design includes one fluorite and one Super UD (Ultra-low Dispersion) element, which significantly reduce chromatic aberration, fringing, and distortion.
Even wide open, the lens produces tack-sharp images throughout the zoom range, with excellent edge-to-edge consistency. This is especially impressive considering the lens covers such a broad focal length. Stopping down slightly improves contrast and sharpness, but even at its maximum aperture, it’s highly usable.
Color rendition is vivid and natural, and the lens handles flare well thanks to advanced lens coatings such as Air Sphere Coating (ASC), which helps suppress backlighting issues and ghosting.
Image Stabilization (IS)
One of the key upgrades over the Mark I version is the 4-stop Image Stabilizer, which dramatically improves handheld shooting performance. The IS system includes three modes:
- Mode 1 – Standard IS for stationary subjects.
- Mode 2 – Panning mode, useful for tracking moving subjects horizontally.
- Mode 3 – Only engages IS during the exposure itself, ideal for erratic subject movement such as birds in flight.
This flexibility makes it easier to shoot in low-light conditions or at slower shutter speeds, which is crucial when you’re shooting at 400mm and trying to avoid motion blur without a tripod.
Autofocus Performance
The lens uses Canon’s ring-type USM motor, which delivers fast, accurate, and virtually silent autofocus. Combined with a high-performance CPU and optimized AF algorithms, focusing is near-instantaneous even when tracking fast-moving subjects like birds, jets, or athletes.
Thanks to full-time manual focus override, photographers can fine-tune focus without switching out of AF mode. This is especially useful when shooting through grass or fences, or when you want to precisely lock focus on an animal’s eye.
The close focusing distance of 0.98m (3.22 ft) is another standout feature. It offers near-macro capabilities at 400mm with a maximum magnification of 0.31×, making it surprisingly useful for shooting small birds, insects, or details like textures and patterns on animals.
Real-World Use Cases
Wildlife Photography
This lens shines in wildlife photography. Whether it’s photographing birds, foxes, or deer, the 100–400mm focal length gives excellent reach while maintaining portability. On an APS-C camera like the Canon 90D or 7D Mark II, the effective field of view becomes 160–640mm, which makes it even more versatile for distant subjects.
Sports and Action
Thanks to the lightning-fast autofocus and solid image stabilization, it’s great for sports, especially outdoor events like football, motorsports, or track and field. The lens tracks motion reliably, even under suboptimal lighting conditions.
Aviation and Airshows
For aviation photographers, the lens is an absolute favorite. The ability to shoot aircraft at a distance, pan with speed, and achieve sharp results at 400mm is critical. Mode 2 and 3 IS settings are a big help here.
Travel and Landscape
Though large and heavy compared to standard zooms, it’s still relatively compact for its focal range. Many travel photographers take this lens to places like African safaris, the Arctic for polar bears, or coastal cliffs for seabirds. It can also compress distant mountain ranges beautifully for layered landscape compositions.
Comparisons
vs. Canon EF 70–200mm f/2.8L IS III
- Reach: The 100–400mm clearly wins for reach.
- Aperture: The 70–200mm offers a constant f/2.8, making it better in low light.
- Weight: Surprisingly similar, but the 100–400mm gives more focal length flexibility.
vs. Canon EF 400mm f/5.6L USM
- Prime vs. Zoom: The 400mm prime is lighter and a tad sharper at 400mm but lacks IS.
- IS: The 100–400mm has modern 4-stop IS, a big advantage.
- Versatility: Zoom flexibility is a massive benefit for dynamic scenes.
vs. Sigma 150–600mm Contemporary/Sport
- Reach: Sigma wins with 600mm.
- Sharpness: Canon is sharper overall and faster to focus.
- Build: Canon has superior build quality, but Sigma Sport is close.
Price and Value
At launch, the Canon EF 100–400mm f/4.5–5.6L IS II USM retailed for around $2,199 USD, but it’s often available for less on the used market or during sales. For what it offers—exceptional optics, excellent AF, pro-grade build, and class-leading stabilization—it’s considered excellent value.
The lens is fully compatible with Canon’s extenders (teleconverters). Using a 1.4× extender, you get up to 560mm at f/8, and with cameras that support f/8 autofocus (like the 5D Mark IV or 1D X series), you can maintain AF functionality, albeit with reduced speed.
Final Thoughts
The Canon EF 100–400mm f/4.5–5.6L IS II USM is a near-perfect telephoto zoom lens that manages to balance portability, performance, and versatility in a way few other lenses can. Its reputation for sharpness, fast and accurate autofocus, and effective image stabilization has made it a staple in the bags of birders, sports shooters, travel photographers, and professionals worldwide.
Even in 2025, with the rise of Canon’s RF mirrorless system, this lens remains a fantastic investment, especially when paired with a DSLR like the 5D Mark III, 7D Mark II, or even newer bodies with EF adapter support.
