Canon’s EF-S 18-135mm f3.5-5.6 IS USM is a general-purpose zoom for its DSLRs with cropped-frame / APSC sensors. Launched in February 2016 alongside the EOS 80D body, it becomes Canon’s third 18-135mm zoom for the EF-S mount. Like its predecessors it sports a flexible 7.5x / 29-216mm equivalent range that takes you from standard wide-angle to telephoto, making it ideal for travel and general walk-around use.
The biggest difference between the three Canon EF-S 18-135mm zooms are their autofocus systems. The latest EF-S 18-135mm IS USM is the first to employ a Nano-USM motor that combines the smooth and quiet operation of Canon’s STM models for movies with the speed of traditional USM for action shooting. It really works in practice too with the EF-S 18-135mm IS USM feeling much snappier than the previous EF-S 18-135mm IS STM model for sports, but remaining smooth and inaudible for video work. The EF-S 18-135mm IS USM also features rack gearing on the lower side of its zoom ring, allowing it to mate with the optional PZ-E1 adapter; this provides motorized zoom operation and if you have the EOS 80D, you can even operate the zoom remotely using a Wifi-connected smartphone.
In terms of optical construction, the EF-S 18-135mm IS USM employs 16 elements in 12 groups, an f3.5-5.6 focal ratio with seven diaphragm blades, a closest focusing distance of 39cm for a maximum magnification of 0.28x, and optical image stabilisation good for four stops of compensation. Like its predecessor, the range means it’s a fairly hefty lens, measuring 77mm in diameter (with a 67mm filter thread), 96mm in length and weighing 515g, but equally the flexibility means you’ll rarely want for anything else for general-use. The previous EF-S 18-135mm STM may be a little cheaper and still great for movie use, but I’d say it’s worth spending the extra on the EF-S 18-135mm IS USM most importantly for its faster USM autofocus but with the added bonus of adding a motorized zoom control if desired.
I shot with the EF-S 18-135mm IS USM as my main lens during a 6800 mile roadtrip across the USA. Check out some of my sample images.