Users of 35mm SLRs have long enjoyed extreme-range zoom lenses of 28-200mm and, more recently, 28-300mm. These lenses can be used on digital SLRs, too, but since most D-SLRs have image sensors that are considerably smaller than a full 35mm film frame, these zooms provide a much narrower field of view when used on D-SLRs— equivalent to 42-300mm and 42-450mm on a 35mm SLR.

Now, D-SLR users can enjoy true wide-to-supertele-zoom versatility, thanks to the recent introduction of the 18-200mm zoom. Tamron’s AF18-200mm ƒ/3.5-6.3 XR Di II is an excellent example of the breed. Designed specifically for APS-C-sensor digital SLR cameras (on which it provides the equivalent of a 28-300mm focal length on a 35mm SLR) and featuring a minimum focusing distance of 17.7 inches at all focal lengths, this 11.1x zoom is a versatile tool. In fact, many users of APS-C-sensor D-SLRs will find that this one lens can handle all of their shooting needs.

Along with the advantages of convenience and keeping you ready for just about any photo op that might present itself, the extreme-range zoom means you won’t be changing lenses nearly as often, which in turn means less dust on your D-SLR’s image sensor—a nice bonus.

The AF18-200mm employs XR (Extra Refractive Index) glass, three hybrid aspherical elements and two LD (low-dispersion) glass elements in its 15-element/13-group design, resulting in a very compact lens (2.9x3.3 inches and 14 ounces) that’s well corrected for spherical aberration, chromatic aberrations and barrel distortion. The optical design is optimized for the smaller APS-C image sensors, directing light rays to the pixels more effectively and producing less light falloff at the edges than lenses designed for 35mm SLRs. Multi-layer internal surface coatings minimize ghosting and flare, which is especially important for digital SLRs and their shinier-than-film image sensors.

I found the AF18-200mm to be a terrific general-purpose lens, able to handle everything from scenic vistas and portraits to close-ups, sports-action and distant wildlife shots. Sharpness, contrast and color reproduction were excellent, and autofocusing performance on my midrange Canon D-SLRs was quick and accurate, albeit not as silent as with Canon’s USM lenses.

Full travel of the focusing ring is about a one-eighth turn, so you can manually focus quickly and won’t sprain a wrist in the process. While the lens extends considerably when zoomed from 18mm to 200mm, the focusing ring stays put, making it easy to reach at all focal lengths. The focusing ring’s knurled grip is about one-third the width of the zoom ring’s, making it easy to find the right ring with the camera at your eye.

Other nice touches include a zoom lock, which keeps the lens at its shortest physical length for easy on-camera carrying and a flower-shaped lens hood that provides flare protection without vignetting. Speaking of vignetting, you can’t use this (or other Tamron Di II lenses) on 35mm SLRs or full-frame D-SLRS, or vignetting will occur—a by-product of optimizing a lens specifically for the smaller-sensor D-SLRs.

Contact: Tamron, (631) 858-8400, www.tamron.com.

SPECIFICATIONS
Lens Mounts: Canon, Minolta-D, Nikon-D and Pentax
List Price: $726