Tiny wide-ratio zoom lens "performs big" It's the smallest of the biggest: The widest-ratio zoom lenses on the market are the 28-300s, and Tamron's new AF28-300mm f/3.5-6.3 XR Ultra Zoom Macro is far and away the smallest among them (as of this writing, anyway). At 3.3 inches in length (at 28mm; it extends to 6.4 inches at 300mm) and 2.9 inches in width, and weighing a mere 14.8 ounces, the tiny wide-range zoom was recently named European Lens of the Year 2002-2003 by EISA (the sixth time a Tamron zoom lens has received such an honor).
What does this lens have going for it besides mini-ness? Excellent optical performance. A maximum reproduction ratio of 1:2.9 at the 300mm setting (and a minimum focusing distance of just 19 inches at all focal lengths). Use of Extra Refractive Index glass—the "XR" in the lens' name—helps produce a smaller, sharper lens. Three Hybrid Aspherical elements and two high-grade Low Dispersion (LD) glass elements (one element is an AD-Hybrid Aspherical unit of anomalous dispersion glass with an aspherical coating) minimize distortion, flare and chromatic aberrations, thus solving the major problems that plague designers of wide-ratio zoom lenses. A new injection-molded Super Hybrid bayonet lens mount made of stainless steel and engineering plastic combines greatly reduced weight with the strength of the brass material used in conventional lens mounts. A Moving Triple Cam design (introduced in the AF28-200mm XR Super Zoom) improves zoom torque for smooth, consistent performance throughout the zoom range, and makes for a more-compact lens.
But wait; there's more: A nine-blade diaphragm yields pleasantly blurred backgrounds for portrait and macro subjects. A Zoom Lock keeps the lens at it shortest physical length for easy carrying. The attractive high-quality pearl-black finish makes for a very attractive piece. And an included flower-shaped lens hood provides vignetting-free flare protection.
Other specs include 15 elements in 13 groups, a minimum aperture of f/22-38, angles of view from 75-8°, and a 62mm filter size. If the compact size doesn't make it obvious which lens you're checking out, the AF28-300 XR's model number is A06.
In Use
Our test lens focused quickly and accurately, with a soft whirring sound (we tested the Canon-mount version, with focusing motor in the lens). Focusing is internal, meaning the lens doesn't change physical length as it focuses, and the front element doesn't rotate—handy when using orientation-sensitive lens attachments such as polarizers and graduated filters. Auto and manual focusing modes are selected as with the camera manufacturer's lenses: via a switch on the lens for Canon-mount versions, and via the camera body's switch with the others.
Separate control rings are provided for zooming and focusing. The zoom ring is nearest the camera body, with a rubberized gripping surface more than twice as wide as that of the focusing ring so that it's easy to differentiate between the two with the camera at your eye. Both rings can be operated easily with a normal grip on the camera body. The zoom ring is marked at 28, 35, 50, 70, 120, 135, 200 and 300mm for easy reference, should a specific focal length be desired (most folks just zoom as they look through the viewfinder, stopping when the composition looks right). The focusing ring has a distance scale marked in both feet and meters, but there's no depth-of-field scale. Zooming from 28mm to 300mm (or vice versa) requires about 1/4 turn of the ring; focusing from infinity to 1.6 feet (or vice versa) about half that.
Because longer-focal-length lenses generally weigh more than the camera bodies to which they are attached, most come with a tripod mount so that the lens rather than the camera can be mounted on a tripod to minimize stress on the lens mounts. The 28-300 XR doesn't have a tripod mount, but the lens is light enough that it shouldn't unduly stress the camera's lens mount when the camera rather than the lens is attached to the tripod.
Our test images (shot mostly on ISO 100 color-slide film) were sharp, with good contrast and color, and no evidence of vignetting (except for two frames where we accidentally had knocked the lens hood askew). Shooting directly toward a bright street light at night produced the expected small-aperture flare star, but contrast remained crisp even with the light source in the frame.
We've never encountered an extreme-range zoom that didn't exhibit barrel distortion at the wide end and pincushion distortion at longer focal lengths to some degree, and this one does, too. But it's certainly within reason for a 28-300mm zoom, and should be of concern only in photos where subjects with long straight lines appear near the edges. As the accompanying shots demonstrate, most of the time you couldn't tell if the image was shot with a wide-range zoom or a single-focal-length lens.
If you're looking for one lens that can handle a tremendous range of shooting situations yet fits both camera bag and budget, this one definitely deserves serious consideration.
The AF28-300mm XR Ultra Zoom Model A06 has a street price of $429, and is available in mounts for Canon, Minolta, Nikon and Pentax AF 35mm SLRs (it works great on digital SLRs that use these mounts, too!). For more info, contact Tamron USA, Inc., 10 Austin Blvd., Commack, NY 11725; 631/858-8400; www.tamron.com.
