In summary
Slightly larger than its predecessor (which we reviewed in November,2009), the new EF-S 18-135mm f3.5-5.6 IS STM lens has been developed to match the EOS 650D and offers features to complement the camera’s movie capabilities. A new STM (stepping-motor) system provides smooth,quiet auto focusing and is especially valuable for minimising pick-up of camera operating sounds while shooting movie clips.
Buy this lens if:
– You want a general purpose lens for everyday shooting and it’s offered with the EOS 650D body.
– You’d like a lens that requires no readjustment when you fit polarisers and graduated filters.
Don’t buy this lens if:
– You require high resolution at all focal lengths, along with good flatness of field.
– You need close focusing and macro capabilities.
Full review
Slightly larger than its predecessor (which we reviewed in November,2009), the new EF-S 18-135mm f3.5-5.6 IS STM lens has been developed to match the EOS 650D and offers features to complement the camera’s movie capabilities. A new STM (stepping-motor) system provides smooth,quiet auto focusing and is especially valuable for minimising pick-up of camera operating sounds while shooting movie clips.
Designed specifically for Canon’s DLSR cameras with ‘APS-C sized’ sensors, this lens is a good choice for photographers who want a single body+lens configuration. The18-135mm zoom range (28.8-216mm in 35mm format) suits a wide variety of subjects and is ideal for travel photography.
The EF-S 18-135mmf3.5-5.6 IS STM lens. (Source: Canon.)
Although marginally heavier than its predecessor, the18-135mm STM lens weighs only 480 grams and is 96 mm long. Its optical design comprises 16 elements in 12 groups with one UD element plus one high-precision aspherical lens element (see diagram below). All elements are made from eco-friendly lead-free glass.
This lens has a minimum focusing distance of 39 cm, which is closer than the 45 cm limit of the previous 18-135mm lens. It provides a maximum magnification of 0.06x at 18mm and 0.28x at 135mm. An EMD (ElectroMagnetic Diaphragm) provides a circular aperture for attractive bokeh. The filter diameter is 67 mm.
Fast autofocusing is a key feature of this lens, which takes advantage of the stepping motor technology and integration with the improved AF system in the EOS 650D, on which we tested it. This enables it to provide smooth and silent autofocusing using the camera’s Movie Servo AF mode.Continuous AF is also supported during live view shooting with the 650D.
When the camera’s AF mode is set to One Shot AF, full-time manual focusing is supported in One Shot AF mode after autofocusing is complete. You simply half-press the shutter button and turn the focusing ring until the image appears sharp.
A new optical stabiliser provides up to four steps of shutter speed compensation. In addition, the lens will automatically determine whether normal shooting or panning is occurring and automatically select the most appropriate IS mode.
The stabiliser can be left on when the camera is tripod-mounted, although as it uses battery power, Canon recommends it be switched off. A new Dynamic IS function is available for movie shooting to compensate for movements when the photographer shoots while walking. It automatically activates when the movie mode is selected.
The lens is supplied with front and rear caps plus a printed multi-lingual instruction manual. The lens hood (EW-73B) is sold separately. According to the manual, this lens is not suitable for use with tele-extenders and no close-up attachments are available for it.
Build and Ergonomics
Build quality is similar to the EF-S 18-135mm f/3.5-5.6IS. While made mainly from black polycarbonate, the new lens has a stainless steel mounting plate that ensures a secure fit on the camera body long term.The new lens feels just as solid and its ‘leather-tone’ coating looks smart.
The inner barrel extends by roughly 55 mm when the lens iszoomed in to the 135mm focal length but it doesn’t rotate and internal focusing allows the use of angle-critical attachments like polarisers and graduated filters.
The focusing ring is a 14 mm wide band approximately 10 mm behind the leading edge of the outer barrel. It has a finely-ridged rubber coating that provides a secure grip. The new lens lacks a distance scale but, unlike the earlier lens, manual focus over-ride is available in AF mode.
Behind the focusing ring is a 42 mm wide zoom ring that has a 30 mm wide, thickly ridged rubber collar. The trailing edge of this ring is engraved with focal length markings for 18mm, 24mm, 35mm, 50mm, 85mm and 135mm positions.
Two slider switches are located on the left hand side of the 18 mm wide section of the barrel behind these engravings. The top one selects between AF/MF and the lower one switches the stabiliser on and off. A little further around is a zoom lock, another feature missing on the previous lens.
The EF-S 18-135mm f3.5-5.6 IS STM lens was a comfortable fit on the EOS 650D body we used for our tests. Both focusing and zoom rings moved smoothly and positively with no slack.
The zoom ring rotates through approximately 45 degrees as you span the focal length range and we found the markings on the lens barrel to be accurate for the indicated focal length settings.
In the process, the maximum and minimum apertures change with focal length as follows:
|
Focal length |
Max. aperture |
Min. aperture |
|
18mm |
f/3.5 |
f/22 |
|
24mm |
f/4.0 |
f/25 |
|
35mm |
f/4.5 |
f/29 |
|
50mm |
f/5.0 |
f/32 |
|
85mm |
f/5.6 |
f/36 |
|
135mm |
f/5.6 |
f/36 |
All operations of this lens, from the focus lens drive used during zooming, to focus ring movement detection and control/drive, are operated electronically. The lens draws power from the camera body. When it’s not operated for a certain time, the Auto Power Off setting switches it off. After deactivation, it can require up to one second to power-up again.
Performance
We found a significant improvement in AF performance when the review lens was used on the EOS 650D body. It wasn’t quite as fast on the EOS 1100D so the gains probably result from improvements to the camera’s AF system. They were most evident in low light levels, both with the viewfinder and in live view mode. Touch AF was particularly effective with this lens on the EOS 650D.
Improvements to the image stabiliser system were less obvious, although the system in the new lens was excellent. Canon’s claim of four f-stops stabilisation advantage is as credible as it was for the previous18-135mm lens.
Imatest showed resolution to be quite variable and similar to the previous lens. The 35mm focal length produced the highest overall resolution at f/5.6 but, as before, it failed to reach the resolution levels we expected from the 650D’s 18-megapixel sensor.
Edge and corner softening were slightly less than we found with the previous lens at most apertures. As before, diffraction reduced resolution from about f/8 throughout the focal length range. The graph below shows the results of our Imatest tests.
Lateral chromatic aberration was mostly in the ‘low’ band, dipping into the ‘negligible’ band in the middle apertures for the 50mm and 85mm focal lengths. Coloured fringing could be seen near the edges of shots when they were enlarged to 100%, as shown in the Samples section below. In the graph below, the red line marks the border between ‘negligible’ and ‘low’ CA with the green line separating ‘low’ and ‘moderate’ CA.
Barrel distortion was obvious in shots taken with the 18mm focal length but became relatively insignificant at 24mm. Slight pincushioning became visible at 50mm but we found no noticeable distortion at 135mm.
Vignetting (edge and corner darkening) could be seen in open-aperture shots at all focal length settings. By f/5.6 this problem was fully resolved.
Backlit subjects were handled very well, with very little loss of contrast due to veiling flare. Bokeh was also quite attractive in close-up shots at maximum aperture ““ although not outstandingly beautiful.
Buy this lens if:
– You want a general purpose lens for everyday shooting and it’s offered with the EOS 650D body.
– You’d like a lens that requires no readjustment when you fit polarisers and graduated filters.
Don’t buy this lens if:
– You require high resolution at all focal lengths, along with good flatness of field.
– You need close focusing and macro capabilities.
SPECS
Picture angle: 64 degrees 30 minutesto 9 degrees 30 minutes
Minimum aperture: f/22-f/36
Lens construction:16 elements in 12 groups (includes one UD element and a PMo aspheric element)
Lens mount: Canon EF-S
Diaphragm Blades: 7
Focus drive: STM stepping-motor
Stabilisation: Yes (4 stops compensation)
Minimum focus: 39 cm across the entire zoom range
Maximum magnification: 0.28x
Filter size: 67 mm
Dimensions (Diameter x L): 76.6 x 96 mm
Weight: 480grams
TESTS
Based on JPEG files taken with the EOS 650D body.
SAMPLES
Vignetting at 18mm.
Vignetting at 50mm.
Vignetting at 135mm.
Rectilinear distortion at 18mm.
Rectilinear distortion at 50mm.
Rectilinear distortion at 135mm.
18mm focal length, ISO100, 1/250 second at f/9.
Crop from the above image at 100% reproduction showing slight coloured fringing.
135mm focal length, ISO 100, 1/400 second at f/7.1.
Close-up at135mm; ISO 100, 1/500 second at f/5.6.
Flare; 18mm focal length, ISO 100, 1/500 second at f/8.
Strong backlighting; 18mm focal length, ISO 200, 1/1250 second at f/5.6.
97mm focal length, ISO 100, 1/320 second at f/8.
Additional image samples can be found with our review of the EOS 650D.
Ratings
RRP: AU$749; US$550
- Build: 8.5
- Handling: 8.5
- Image quality: 8.3
- Versatility: 9.0