The 70-200m F2.8 is one of Canon's L series professional quality lenses, and therefore built to the very highest standards. The construction appears to be essentially of metal, and the internal focus and zoom design gives a sense of robustness and solidity to the 'one-piece' design which few other lenses match. The lens is moisture and dust resistant, and incorporates a rubber 'O'-ring around the mount to provide a seal with the camera body. The striking off-white colour to is apparently designed to reduce the effects of heating under direct sunlight (and quite possibly not without some degree of marketing value).
The lens is pretty typical in size for its class, and therefore potential upgraders should appreciate that it's significantly larger and heavier than consumer telezooms such as the 70-300mm F4-5.6 IS USM. This therefore may well not be a lens you'll want to carry around all day when on a hike though the jungle, for example.
On the camera
This is a sizeable lens, and therefore handles best on larger bodies such as the 1D(s) series, although it still works very well on intermediate bodies such as the 5D and 40D. The balance of the lens is excellent, and the zoom ring is positioned perfectly towards the centre of gravity of the lens/body combination; however a distinct shift in grip is required to operate the manual focus ring. Perhaps surprisingly, the lens also proves to be reasonably workable on compact EOS bodies such as the 450D, by holding the combination primarily by the lens and treating the camera essentially as a glorified rear lens cap.
This lens features Canon's ultrasonic motor for autofocus, which performs extremely well; it's practically silent in operation, and we saw no evidence of any systematic focusing errors. We found focusing to be extremely fast and accurate in everyday use on all of the bodies used for testing (ranging from the entry-level EOS 450D to the top-of-the-line EOS-1Ds Mark III), however it must be noted that focus speed and accuracy is dependent upon a number of variables, including the camera body used, subject contrast, and light levels.
Lens body elements
The lens uses Canon’s all-electronic EF mount. This means it will fit all of Canon's DSLRs regardless of sensor format, APS-C, APS-H or 35mm full-frame. It's also compatible with Canons 1.4x and 2.0x 'Extenders' (known to the rest of the world as teleconverters), retaining full autofocus and image stabilization functionality.
A rubber seal around the outside of the mount protects dust and water ingress.
The filter thread is 77mm, which has become the de facto standard for professional lenses, and common across much of Canon's 'L' series lineup. It does not rotate on autofocusing, which should please filter users.
The petal-type ET-68 lens hood is supplied as standard and fits to the front of the lens via a bayonet mount. It's 95mm/3.75" deep, lined with flocking to minimize reflection of light into the lens, and reverses for storage.
The zoom ring rotates 60 degrees anti-clockwise from 70mm to 200mm. The ribbed rubber grip is 32mm wide, and the zoom action extremely smooth and precise.
In common with other 70-200mm F2.8 lenses (and Canon's 70-200mm F4s), the zoom action is entirely internal.
The focus ring is a generous 30mm wide, and rotates 140 degrees clockwise from infinity to 1.4m. It does not rotate during autofocus, and the full-time manual system allows tweaking of the focus even when the lens is set to AF. Again the action is extremely smooth and precise.
A distance scale is provided with markings in both feet and meters, and includes infra-red correction marks for 70mm and 100mm focal lengths. The focus ring travels slightly past the infinity mark, apparently to allow for the effects of ambient temperature variations.
The side of the lens barrel is adorned with no fewer than four switches. At the top we have an AF range switch which can be used to limit closest focus to 2.5m (useful to minimize AF time and possible hunting problems), and below that the autofocus/manual focus mode switch. Both are well-sized and positive in action.
The lower pair of switches control the image stabilization mechanism; the On/Off switch has a slightly different shape, presumably to aid identification by touch alone. The bottom switch selects either stabilizer mode '1' (normal, for static subjects), or '2' which automatically detects panning motion, and then stabilizes in the other dimension only.
A nice touch is the provision of a ribbed grip at the end of the barrel, which aids mounting and dismounting of the lens from the camera.
The lens comes with its own detachable tripod mount ring, which is lined with a Teflon sleeve for smooth rotation. The line at the top aligns with a mark on the lens for landscape format shooting, but unfortunately there are no corresponding marks on the lens for portrait format alignment.
One irritation with this design is that it can't be removed while the lens is attached to the camera.
Reported aperture vs focal length
This lens allows an aperture range from F2.8 to F32 at all focal lengths.