Canon EF 100-400mm f/4.5-5.6 USM L IS - Review / Test Report
Lens Reviews - Canon EOS (APS-C)

Review by Klaus Schroiff, published July 2005

Special thanks to Markus Stamm (1st sample) and Friedhelm Poschadel (2nd sample) for providing this lens!


Released back in late 1998 the Canon EF 100-400mm f/4.5-5.6 USM L IS is Canon´s long range zoom lens primarily meant for sports-, wildlife- and press photography. Due to its rather small max. aperture it isn´t quite suitable for portraits.
On an APS-C DSLR the field-of-view resembles a whopping 160-640mm lens on classic (full-frame) SLRs. With a price tag around 1400EUR/US$ it isn´t exactly cheap but still within the reach of many serious amateurs.

The lens has an very good build quality - no wobbling whatsoever inc. smooth focusing action. It has a push-pull zoom mechanism which has both pros and cons. You can zoom very fast if necessary but at cost of accuracy. The amount of zoom friction can be adjusted using a dedicated control ring. It´s also possible to lock the lens at a certain zoom position so zoom creeping is not an issue.
Personally I would rather prefer a rotating zoom ring instead which is also present in competing or similar products like the Sigma AF 80-400mm f/4.5-5.6 EX OS or Nikon´s 80-400mm f/4.5-5.6 ED VR. The push-pull design is also supposed to suck in dust which isn´t exactly a favorable feature till Canon gives us an anti-dust solution for the image sensor. However, during the field testing I didn´t really experience anything in this respect. Besides both the Sigma as well as the Nikkor aren´t really different because their massive inner tube should cause similar dust sucking effects so if it is a problem it´ll be a general problem in this lens class. True inner focus 4x or 5x zooms in this range aren´t overly likely to emerge in this range due to the physical size requirements for the 400mm setting.

One of the primary selling argument is the IS (Image Stabilizer). It is a 1st generation variant (or v1.5 depending how you look at it) which gives you the equivalent of two extra f-stops in handholdability - at cost of shutter speed with all the related side effects regarding subject and/or background movements. On the EOS 350D with a max. 640mm equivalent this translates to a min. shutter speed of 1/160sec which roughly matches with my field experience. So far I was never able to achieve critically sharp results on a reliable basis beyond Canon´s claims. Others may be more successful here.
The IS cannot be used on a rock solid tripod because it tries to detect motion where there is none causing the IS to produce erratic effects. However, few tripods are rock solid and my experience is that IS can be used here unless you keep it activated for long. There´re two IS modes (which is why I referred to a v1.5 IS above) - mode on corrects motion in both vertical and horizontal axis whereas mode two corrects vertical motion only. The latter is meant for action photography when you´ve to track objects. Mode one is intended for static scenes only.

The lens features a ring-type USM drive resulting in a very fast and virtually silent AF operation. Full-time manual focusing is possible in one-shot AF mode. To avoid unnecessary hunting there's a focus limiter where you can choose between 1.8m-infinity or 6.5m-infinity.

The optical construction is made of 17 elements in 14 groups including one CaF2 (fluorite) and one SUD (Super Ultra-low Dispersion) elements. The lens features 8 aperture blades. The min. focus distance is 1.80m resulting is a max. object magnification of ~1:5 at 400mm. A floating system is used to optimize the image quality throughout the focus range. The lens has a size of 189x92mm with a total weight of 1360g inc. the detachable tripod mount. The filter size is 77mm. It is compatible both to the Canon EF 1.4x and 2x tele converters.