The Canon EF-S 18-135mm f/3.5-5.6 IS USM fits Canon’s APS-C format DSLRs, including the Rebels, right up to the Canon EOS 7D Mark II. It offers a much longer zoom range than a regular standard zoom for these cameras and almost qualifies as a ‘superzoom’. It’s an EF-S lens, however, which means it can’t be used on Canon’s full-frame cameras like the EOS 6D and above.
Canon EF-S 18-135mm f/3.5-5.6 IS USM features
Canon has a veteran EF-S 18-200mm superzoom with a basic autofocus system that remains unchanged, but the smaller 18-135mm lens has undergone two updates. The first ushered in a stepping-motor autofocus system and this edition has a Nano USM actuator that aims to combine quick stills performance with smooth and silent transitions when shooting movies.
Compared to other superzoom lenses, it’s not particularly impressive for outright zoom range, falling short at the telephoto end, equivalent to 216mm in full-frame terms. It’s barely any more compact or light than other superzooms either, but handling is refined and the image stabiliser works well. You need to buy the hood separately if you want one.
How we test lenses
We use specially-developed charts shot in controlled lighting conditions and the Imatest imaging analysis suite. We measure lens resolution across the frame at different focal lengths and apertures, together with chromatic aberration (colour fringing) and distortion, which are the two most troublesome lens aberrations.
The sharpness values are an indication of how well the lens resolves fine detail. The higher the figure, the sharper the fine details in the picture will look.
It’s good at mid to long zoom settings, but could be better at short focal lengths.
Colour fringing is also called chromatic aberration, and it produces the cyan-magenta or blue-yellow fringes you sometimes see around object outlines, especially towards the edges of the picture.
The Canon keeps colour fringing well under control throughout the zoom range.
Distortion is where the lens displays straight lines as slightly bowed and it’s most noticeable towards the edges of the picture. Wideangle lenses typically produce ‘barrel’ distortion, telephotos often produce ‘pincushion’ distortion.
Barrel and pincushion distortions are less severe than in most DSLR superzooms.
The STM edition of the lens is no slouch for autofocus, but AF in the new edition is super-fast, practically snapping into place. An upside of the relatively meagre zoom range is that sharpness only drops off marginally at the long end, and distortions are less pronounced than with most competing lenses.