A phenomenal zoom lens with insane versatility.

Canon has another winner here.

I purchased this lens along with a 28-70mm f/2.8L lens with the thought that this would wind up being my "zoo" lens, or nature photography lens. It was purchased at Adorama for $1800ish for the IS (image stablization) version.

First, a bit about the lens. It's a large lens with internal focusing. It's a very light tan color with a 77mm front element like many other L-class lenses. It's fairly large at around a foot long, chuckling at all but the largest carry-around camera bags. The lens itself does not telescope in or out, it uses 100% internal focusing. The EF mount is somewhat rubberized to keep moisture, dirt and dust from entering your camera, and the lens itself is built like a tank in typical L fashion. This lens will last. Included with the lens is a hard-sided leather bag and a lens hood, something ALL lenses should come with.

The inner zoom ring (closer to the mount) is self explanatory, and the lens boasts an f/2.8 maximum aperture at all focal lengths. This is insanely fast for a 200mm focal length, allowing very good versatility in a wide range of shooting situations. The focus ring is operable even when Autofocus is enabled should you have a better eye than its autofocus system. Let's face it, sometimes your eyes are sharper than any autofocus system.

The lens also supports the IS image stablization system, which incorporates the use of gyrosensors to minimize camera shake at lower shutter speeds. Interestingly, it's their 2nd generation IS that supplies 2 modes of IS, one for full-scene stablization for general photography, and a "panning" IS mode for side-to-side shots (vehicles in motion, etc) to achieve good focus of centered subjects along a moving background while panning. Very nice.

Lens performance is excellent. Photos are tack sharp at all focal lengths. While I wouldn't say it's as "Razor Sharp" as the 28-70mm f/2.8L, I would certainly say it's mucch sharper than any of the lower-end canon zooms in its range, particularly the 75-300mm f/4-5.6 non-L I have direct experience with.

The lightning fast autofocus performance, internal focusing, build quality, sharpness, speed and 2nd generation IS makes this lens a FAR better choice for nature photographers, and even maintains excellent sharpness and speed with a 1.4x Teleconverter. Using a 1.4x Teleconverter and the D60's normal 1.6x focal length multiplier, i'm able to zoom in to a 480mm length at f/4, losing only one stop of light and a slight degradation in sharpness. This allows for amazing shots printed up to 11x17. While the autofocus system slows down a bit with the 1.4x Teleconverter, it still outperforms any non-L class zoom lenses in this range.

Sports photographers will love this lens, particularly those photographing indoor sports. Its fast speed allows for excellent shots in sometimes less-than-favorable stadium lighting conditions, and excellent versatility under a wide range of other conditions. Its relatively long focal length will let you get fairly close to the action provided you're in a good spot or on the sidelines. Of course, if you REALLY need to get close to the action, there's also a 100-400mm L-class lens that might be better suited for you, particularly if you are in more favorable lighting conditions. It's a bit slower than the 70-200mm f/2.8L obviously, but if you need extreme focal lengths that lens may be a better choice. Birdwatchers should also take note of this. It seems you can NEVER get too close to your subject.

All the warm fuzzies having been said, there are a few asthetic considerations you might want to take into account when purchasing this lens. If you're planning on using this as an "event" lens, please be aware that its lighter color and size will make you a rather obvious photographer. If you've been tapped on the shoulder to photograph a party and are trying to get some candid shots that normally require a less conspicuous piece of gear, you might not be able to pull it off. This will be even more evident when photographing events involving small children. A device of this size is sure to make them aware of you at the very least. This could ultimately change the dynamics of an event, and you should take this into account. Of course, there's always a right tool for the job.