Canon EF-S 18-135mm f/3.5-5.6 IS USM

The latest EF-S 18-135mm has upgraded autofocus

Both Canon 18-135mm lenses on test have very similar styling, from their metal mounting plates to the configuration of zoom and focus rings, and the lack of a focus distance scale. They’re identical in size, both have 16 elements arranged in 12 groups, and apertures with seven-blade diaphragms. The main difference is in the autofocus system.

Whereas the previous edition of the lens has STM autofocus, this one has a newly developed Nano USM system. The aim is to combine the super-fast performance of ring-type USM autofocus for stills photography, while also enabling smooth focus transitions and silent operation for movie capture.

As in the previous lens, the image stabilizer is optimized for shooting movies as well as stills, but the new lens also enables the fitment of an optional PZ-E1 Power Zoom Adaptor (£100/$150). In addition to movie-friendly power zoom functions via a rocker switch, it also enables you to control zooming remotely, when used with a Wi-fi compliant camera body.

Performance

The STM edition of this lens is no slouch when it comes to autofocus speed but the new Nano USM version is incredibly fast for stills, while still maintaining smooth transitions when shooting movies. The image stabilizer is equally effective in both lenses and image quality is very similar. However, sharpness at the centre of the image frame proved slightly less impressive from the new lens, at both ends of the zoom range.