Canon EF 100mm f/2.8 USM L IS macro (Full Format) - Review

The Canon EF 100mm f/2.8 USM L IS macro is the 6th macro lens in the Canon 

EF lens lineup. The lens does not replace the highly popular EF 100mm f/2.8 

USM macro but is meant as a higher quality option featuring Canon's proven 

lens-based IS (Image Stabilizer). Just like most IS lenses the design complexity 

increased quite a bit from only 12 elements in 8 groups in the "conventional" 

macro lens to 15 elements in 12 group. In theory this does allow a higher 

degree of corrections but you also risk more flare in contra light situation.

The build quality is excellent but then we've expected no less from a 

professional grade "L class" lens. The lens body is made of very high quality 

plastics and a metal mount. The broad rubberized focus ring works very 

smooth. 

Similar to the non-L macro lens it features a "true" inner focusing system so 

the lens does not extend when focusing towards closer focus distances. The 

Canon EF extension tubes are supported whereas the EF tele converters cannot 

be used

It took Canon quite a while to release their first macro lens featuring an image 

stabilizer. Nikon won the race here although their VR is not all that efficient in 

macro situations. The Canon lens feature a new "hybrid" IS which does not only 

compensate "conventional" shake but also linear movements. Canon claims an 

efficiency of 2 f-stops at 1:1 magnification and 4 f-stops at standard focus 

distances. These extremes seem to be a little optimistic but they may work out 

at times (and if you skip your coffee). Whether it makes sense to take macro 

images at 1:1 magnification with activated AF and IS is a different story. The 

depth-of-field is so shallow here that shake due to "free hand" shooting is just 

one of your problems. However, the IS is also able to handle tripod-induced 

shake so it does certainly make sense in this scope. The IS efficiency at more 

conventional focus distance remains unchallenged by these thoughts of course.

The AF is based on the usual ultrasonic motor (USM) which is both very fast 

and virtually silent. Nonetheless Canon provides a three step focus limiter in 

order to avoid AF hunting throughout the range which can be a problem when 

using AF in macro situations. During our field tests the AF accuracy was 

excellent. The performance in contrast AF mode (aka LiveView) was also 

decent(both on the 5D II and 50D). That all said - many macro photographers 

do still prefer manual focusing simply because it's easier to fine-tune a specific 

spot.