Intro: When this lens was announced in November 2005, it seemed like the perfect lens. 18-200 zoom (effectively a 27-300 on a 35mm body), VR2, small size and weight, and AF-S. Superzooms have not been known for their "super" performance, though this lens is the best superzoom I have ever seen.

This lens has been hyped up to be the perfect zoom. While it does have it's drawbacks, they are not significant enough to prevent me from using the lens. Given its abilities, it's probably the best "walk round" and travel lens.

Build: One of the first things that are noticeable when you first pick up the lens is the size. It is way smaller than you would expect for such a long zoom bundled with VR. It makes you wonder how they managed to get all the engineering to fit inside.

The lens gives you an effective focal length of 28-300 on a 35mm body. This pretty much means that it can stay on camera for virtually all subject matter. This lens combined with the Nikon 12-24 and a 500D close-up filter (or a light macro lens such as the Tamron 90mm F2.8) makes a very compelling walk-round kit that is light and covers an incredible focal range.

The VR feature is of the new VRII type, one that is supposed to ensure a bit more usefulness of the image stabilization. Nikon states that the VR is capable of getting four stops more than what you would be able to handhold in a normal situation. As long as you have fairly steady hands and don't shake like a leaf in a windstorm I think this is fairly accurate expectation. I have seen more than four, but also less. It really does depend on the the subject and whether or not you had 6 cups of coffee in the morning.

The VR activates quickly and works quite well. The longer it is active though, the less stabilization it seems to offer. This probably has to do with the complex algorithms used to predict camera motion. The longer they try to predict, the less accurate they are. Personally I use the AF-ON button to focus as this saves the VR until I need it. Once the image is in focus, I press the shutter button halfway. This activates the VR and you will see the image stabilize in the viewfinder. Take your shot and you're done. I will also mention that the VR system does use a fair amount of power, so if you can get your inverse focal length shutter speed without it, then don't use it. In low light situations it will help, but in good light it might actually do more harm than good.

As good as VR is though, remember that it will only eliminate camera motion, it does absolutely nothing for subject movement. VR essentially helps you to keep ISO down in low light situations thereby preventing noise.

One of the weaker points of this lens is the zoom ring. The feel is not the same at all focal lengths, probably due to the needed extension and the amount of plastic and glass that is being moved during zooming. The barrel extends almost 2 1/2" at 200mm. The barrel does not rotate so you don't need to adjust rotation dependant filters. I have noticed that some samples suffer from zoom creep when held vertically and some don't. On mine there is some creep in the middle of the focal range, about 50mm to 150mm. At either focal end, there is no creep. If you have the camera on a tripod looking up or down and the lens is creeping, a rubber band on the lens barrel will keep it from moving.

The lens is well suited to almost any body, though it does feel a bit small on the D2X and the D200 with a grip attached.

The switches on the lens are located on the left side which is convenient, as long as you remember which one does what. It takes some time to learn to use them without looking away from the viewfinder.

Performance: Given the vast abilities of this lens I would say that its nearly perfect in every aspect.

Vignetting is nicely controlled throughout the zoom range. The worst occurs at 18mm at fully open aperture. At this focal length there is about a half-stop of light falloff in the corners and by 25mm it is hardly noticeable. Stopping the lens down a couple of stops reduces the falloff to about a 1/4 stop.

Sharpness is exceedingly good throughout the entire range. There has been some noted sample variation, mine has a sharpness sweet spot at F9. Some people have reported anywhere from F8 to F12. At 200mm the sweet spot tends to shift towards F11 or more. Basically the lens is sharp enough to use fully opened, though it's better stopped down for maximum sharpness.

On my sample I have yet to see any chromatic aberration, though it has been mentioned that on some samples it does occur very slightly.

Contrast and color reproduction are excellent.

Autofocus is very quick and snappy in normal light situations. In low light it still works rather well, however at the 200mm end of the zoom range it can start to "hunt" a bit. There just isn't enough light reaching the autofocus sensors at this point to focus accurately.

Bokeh is not bad, but it does lack that soft and creamy look of some of the other superzooms, namely the Tamron 28-300 Di. (The Tamron has other issues though and does not stand up to the 18-200 in any of the other categories.) In my experience 1:1 macro lenses will always produce the best Bokeh.

Flare is not noticeable unless you are shooting directly into the sun. Even then I have seen only mild cases of it, though it does tend to get worse if the sun is at a steep angle. Adding a filter on the front seems to actually result in more flare occurring and I have noticed some ghosting when using a front filter. This occurs even when using high quality multi-coated filters from varying manufacturers.

Summary: An excellent performance lens for the superzoom category. The optics are superb given the long focal length. This lens is the best travel zoom and a general walk-around lens, easily usable for 90% of shots most people take. The lens performs way better than the price would suggest. It's good enough to replace any mid-zooms when you want to go light.

Some distortion detracts from the optical performance, but it is a lot less than one would expect from an 11x zoom. The build quality is not quite there compared to some other Nikkors but it does not have a cheap feel to it. At 200mm the lens becomes an F5.6 which can cause autofocus issues in low light, especially on some of the earlier bodies like the D70. It is still usable, but focusing just takes a bit longer.

I would highly recommend it as a good travel lens or on long hikes where weight is critical. Probably better to carry that extra kilogram of food than another lens eh?

Cheers