Camera Accessories

Built like a tank and ultra-responsive, Canon's EF 70-200mm f/2.8L USM lens is a great tool for fashion, wedding, portrait and event photographers and a good match for full frame DSLRs like the EOS-1Ds Mark II and EOS 5D. The addition of Canon's second-generation image stabilisation technology adds $1,180 to its price tag but gives photographers up to three stops of exposure compensation, which is useful when flash is not permitted.

The new lens offers improved AF performance and high levels of dust and moisture resistance. However, the optical design and construction are essentially the same as the non-stabilised lens. Constructed from 23 elements in 18 groups it includes four 4 UD (Ultra-low Dispersion) elements and has Super Spectra Coating on internal glass surfaces to minimise flare and ghosting and ensure accurate colour reproduction.

The image stabilisation system consists of two vibration gyros and a microcomputer to detect movement and a series of actuators to move the correcting lens elements. Two stabilisation modes are supported on the 70-200mm lens; one using both  X and Y axes and providing stabilisation in all directions, while the other, which is used for panning stabilises in only one dimension. Mode 2 will detect the panning direction automatically and can handle both horizontal and vertical panning.

The solidly-built metal body of the lens has a buff-coloured coating, which reflects infrared radiation and prevents the lens from overheating when it's used in sunlit conditions. Wide, rubber-coated focusing and zoom rings are differently textured for easy identification and provide a secure grip. The focusing ring is towards the front with the zoom ring to the rear.

Behind the focusing ring is a focusing scale with feet and metres indicators that range from 1.4 metres to infinity. The rear edge of the zoom ring is etched with indicators for the 70mm, 100mm, 135mm and 200mm focal length settings. To the left of this scale are four sliders. Closest to the scale is the focus range selector, which has two positions: 1.4m - ∞ and 2.5m- ∞. Useful for dimly-lit situations, the 2.5m- ∞ setting can minimise hunting with mid-range subjects.

Below the focus range selector is the AF/MF switch. Below it is the switch for turning image stabiliser on and off. The final slider selects the stabilisation mode. Behind the zoom ring is the tripod collar, which rotates through 360 degrees. A large thumb-screw lock at the mounting point locks the camera in position at the desired angle.  When the camera is horizontal to the tripod mount, engraved lines on the collar and at the 70mm position for the lens should line up.

The lens is supplied with a large, elongated lens hood with a petal-shaped end, which reverses over the lens for storage. It comes in a handsome semi-rigid carrying pouch with double-zip closures.

Handling
For some photographers, the downsides to this lens will be its size and weight - and also its price. It's large, heavy and highly visible! On the EOS-1Ds Mark III it provides an all-up weight of just under 4.5 kilograms (including camera battery, memory cards and lens hoods). Because it adds more than 1.5 kilograms to the weight of the camera it's fitted to, EF 70-200mm f/2.8L USM lens can be challenging to use hand-held, particularly if the camera is heavy.

Shooting with the camera and lens hand-held is not impossible but the tripod mount can get in the way when you swap from horizontal to vertical shooting. Attached to a tripod or monopod, it's beautifully balanced with an appropriate camera. However, as there's only one tripod socket, you need a fairly solid camera to balance its weight. While it's comfortable on the professional EOS cameras and usable on the EOS 40D, it's unbalanced on the lighter 400D. (You may not need the stabilisation if you will always use the lens tripod-mounted and can save money by choosing the non-stabilised version.)

The locking screw on the tripod collar makes it easy to rotate the camera when it's tripod-mounted - as long as the previous user hasn't done the knob up too tightly.  The zoom ring moves through about a quarter of a turn when you zoom from 70mm to 200mm. It takes a full half turn of the focusing ring to move from the closest focus to infinity.

Screw-on filters are fitted normally to the front lens element. Internal focusing allows the lens to be used with angle-critical filters like polarisers and graduates. You can also fit external filter holders, such as those in the Cokin range.

Performance
Autofocusing with both the EOS-1Ds Mark III and EOS 40D was fast and generally accurate and we found no instances of hunting in low-light conditions. The review lens turned in an excellent performance in our Imatest assessments, with peak performance at around f/8.0, although resolution remained high throughout the aperture and zoom ranges. The graph below plots the results of our Imatest resolution tests against lens aperture settings.

Centre resolution was slightly higher than edge resolution at most apertures and with most zoom settings. However any edge softening was so slight it would be barely visible in shots. Apparent flatness of field was excellent. Image contrast was also excellent - and a match for the resolution. Shots taken in subdued lighting retained plenty of 'punch' while shots in contrasty lighting were still able to retain highlight and shadow details.

Lateral chromatic aberration was consistently on the borderline between the 'low' and 'insignificant' levels at between 0.031 and 0.050 percent of distance to corner. We found no evidence of coloured fringing in any test shots. No vignetting (edge darkening) was evident at small apertures.  Rectilinear distortion was negligible and we found little evidence of flare in backlit shots taken as long as the lens hood was in place.

Bokeh (out-of-focus blur) was very smooth in shots with wide lens apertures and true out-of-focus backgrounds were easy to achieve with both the EOS-1Ds Mark III and EOS 40D.

SAMPLE IMAGES

Shot taken with EOS-1Ds Mark III. 120mm focal length, f/11. ISO 400.

Taken with EOS 40D. 100mm focal length, f/2.8, ISO 400.

Taken with EOS 40D. 173mm focal length, f/7.1, ISO 100.

Taken with EOS 40D. 200mm focal length, f/11, ISO 100.

 
Taken with EOS 40D. 200mm focal length, f/2.8, ISO 640.

Focal length range: 70-200mm
Picture angle: 34 degrees to 12 degrees (diagonal at infinity)
Maximum aperture: f/2.8

Minimum aperture: f/32

Lens construction: 23 elements in 18 groups

Lens mount: Canon EF mount (metal)

Diaphragm Blades: 8
Minimum focus: 1.4 m
Filter size:  77mm
Dimensions (Diameter x L): 86.2mm x 197mm
Weight: 1.570 kilograms

RRP: $3,589

Distributor: Canon Australia; 1800 021 167; www.canon.com.au