Canon EF-S 18-135mm f/3.5-5.6 USM IS - Lab Review / Test
Lens Reviews -
Canon EOS (APS-C)
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Review by Klaus Schroiff, published December 2016
The Canon EF-S 18-135mm f/3.5-5.6 USM IS is the third incarnation by Canon in this lens class. It's not exactly easy to distinguish between the different generations because Canon didn't bother to add the usual mk (I,II,III) to the name. The Canon EF-S 18-135mm f/3.5-5.6 IS was released in 2009, followed by the EF-S 18-135mm f/3.5-5.6 STM IS in 2012 and just recently the current EF-S 18-135mm f/3.5-5.6 USM IS saw its first light. Just based on the name you can already conclude that they differ regarding the incorporated AF motor (micro-, stepping- & ultrasonic motor). As far as we can tell, the optical design of the USM lens has NOT been changed compared to the STM version - Canon's own MTFs and the design schema are identical. Thus we are talking about an evolution of the mechanical design only.
If you followed Canon announcements over the last decades, you may conclude that the USM is either a micro-USM- or ring-USM-type variant. However, this time Canon came up with something new - Nano USM. Nano USM transmits its ultrasonic vibration energy into linear (rather than rotational) movement. Ring-type USM is renowned for for brisk AF operations. This is desirable for fast still life photography but for video you really prefer to have smooth AF action. This is what Nano USM is all about - thus it's similar to an STM drive but faster. Another special feature of the lens is the ability to mate with the optional Power Zoom Adapter PZ-E1 thus you can add smooth, motorized zooming when needed (see also the related contacts at the bottom of the lens in the product image below). Of course, the lens works also perfectly nice for conventional photography which is why you can also buy camera kits featuring this lens.
The 18-135mm lens class is quite popular especially among casual travel photographers. The compact size and broad zoom range is very attractive and the zoom ratio is still moderate enough to avoid most of the severe optical issues that are plaguing the more extreme 18-200mm or 18-300mm lens families.
The build quality has been improved compared to its predecessor. Rather than following the design philosophy of Canon's base kit lenses, it resembles the Canon EF-S 15-85mm f/3.5-5.6 USM IS thus a mid-spec model. The plastic lens body feels a little more high-grade. Both the zoom and especially the focus ring operate smoothly. Unsurprisingly the lens extends quite a bit when zooming towards tele settings. The inner lens tube doesn't wobble when when fully extended. We didn't experience any zoom creeping during our test but Canon has implemented a transport lock just in case.
The AF speed is very snappy and absolutely silent. Similar to STM lenses, manual focusing works "by-wire" thus you are actually driving the focus motor when turning the focus ring. We had no issues with this (as usual). The efficiency of the image stabilizer is rated at 4 f-stops although we'd suggest to plan a little bit more conservative here. The IS is "dynamic" so it switches automatically between static image stabilization and panning for object tracking.
It is worth mentioning that another things has changed - the price tag. The previous generations of this lens were budget items but these times are over. The Canon EF-S 18-135mm f/3.5-5.6 USM IS is listed at 600US$/EUR thus 50% higher. Unfortunately this is something to get used to now that the market is consolidating from its hype phase.
|Equiv. focal length||"29-216mmmm" (full format equivalent)|
|Equiv. aperture||"f/5.6-9" (full format equivalent in terms of depth-of-field)|
|Optical construction||16 elements in 12 groups inc 1x aspherical and 1x UD element|
|Number of aperture blades||7 (circular)|
|min. focus distance||0.39m (1:3.6)|
|Dimensions (L x W)||77.4x96mm|
|Hood||petal shaped, optional|
|Other features||image stabilizer, Nano USM, optional Power Zoom Adapter PZ-E1|