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Ultimate Long-range Zoom for DSLRs?
Tamron updates its superzoom.
Tamron is no stranger to long-range zooms, having introduced one of the first 18-200mm f/3.5-5.6 lenses for APS-C-format DSLRs several years ago. At the time, having a handy, lightweight lens providing a 35mm-equivalent range of 28-300mm (11.1X zoom ratio) along with macro focusing seemed pretty remarkable. The lens sold extremely well and other manufacturers, including camera makers like Nikon and Canon soon followed suit with their own 18-200s, in some cases adding image stabilization.
Last year, Tamron upped the ante with the very successful 18-250mm f/3.5-6.3 that wasn't much bigger or heavier than an 18-200mm but provided a useful bit of extra reach at the tele end. Considering its 13.9X zoom ratio and approximately 390mm-equivalent maximum focal length, its performance is outstanding, especially with respect to flare control and resolution at the longest focal lengths, areas where long tele zooms of the past had a performance deficits.
Now Tamron has unleashed an even longer ultra-long-range zoom in Canon and Nikon mount with truly spectacular specs. It's an 18-270mm f/3.5-6.3 with built-in proprietary VC optical image stabilization. Just how good is this remarkable 15X zoom ratio, 28-419mm-equivalent ultra-zoom? I put it through its paces to find out.
Tour of the lens
Test shots: 28mm
The new Tamron AF 18-270mm f/3.5-6.3 DiII VC LD Aspherical (IF) MACRO (quite a mouthful!) feels substantial, bit it's not all that much larger or heavier than the Tamron 18-250. Weighing in at 19.4 ounces and measuring 3.8 inches long (at the 18mm setting) and 3.1 inches in diameter, it's 4.6 ounces heavier than the 18-250mm, half an inch longer, and about 1/4-inch thicker—not bad for a lens providing 20mm in additional focal length plus built-in vibration compensation (VC). The lens balances beautifully on mid-size DSLRs like the Canon 40D (our test camera) the new 50D, or comparable Nikons like the D90 and D300.
To clear up Tamron's alphabet soup, DiII denotes that it's a member of the second generation of digitally integrated lenses said to be optimized for DSLR cameras with APS-C-size sensors, LD stands for special low-dispersion glass for improved aberration correction, and you probably know that (IF) means internal focusing, which offers performance advantages and is a good thing to have on a zoom whose barrel already extends a bit over 3-1/2 inches in length when you zoom from 18mm to 270mm.
While a bit of extra reach can be useful in, for example, wildlife photography, by far the most significant feature on this lens is vibration compensation, which Tamron calls VC. It's an original design developed by Tamron that employs a tri-axial system that electromagnetically drives a vibration compensator lens that's supported on three steel ball bearings.
Because the compensator lens is free to move in any direction in its low-friction mount, the system provides theoretical advantages that include enhanced compensation for oblique as well as horizontal and vertical shake and enhanced follow-up performance resulting in more stable viewfinder images. Since the mechanism is designed to allow parallel shifting of the compensator lens solely by means of electrical control, the mechanical construction is also simpler and more robust, so the lens can be kept as small and light as possible. This is borne out by the fact that the size and weight are only marginally greater than the Tamron 18-250 without VC.
Before we put this impressive zoom through its paces, let's take a closer look at it. Like most recent Tamron zooms, its metal lens mount and black polycarbonate barrel are very well finished, the latter in a subtly textured pattern. The nearly 2-inch-wide textured rubberized zoom ring and 3/4-inch-wide focusing ring provide a good grip and both turn very smoothly and easily.
As with many AF lenses, there is too little damping on the focusing ring when you switch from AF to MF (manual focusing). Also, as you zoom the lens from 18-270mm, turning the zoom ring requires extra effort as you move it through the center of the zoom range between about 70 and 135mm. This isn't really roughness, but a lack of linear response in the multi-cam zooming mechanism required in a lens of this type and it's not all that noticeable when you're shooting.
Both the focal length and distance scales are legible in black on white and there's a cool looking gold lens identification ring on the barrel, just behind the distance scales. There's also a locking tab on the zoom ring that can lock the lens in its shortest position when it's set to 18mm but it really isn't needed because “zoom creep” is not a problem. Finally there's an on-off switch for the VC system on the side of the barrel—it's recommended that you turn it off when using a tripod.
In the field
Shooting with the 18-270 VC is a very pleasant experience—it's the closest thing ever to the mythical “universal lens” for DSLRs. It makes you wonder how we managed to get along without a 15X zoom that goes reasonably wide and very long. Because the two-stage telescoping polycarbonate barrel is so light and the bulk of the heaviest components are located at the rear, it maintains its excellent balance even when fully extended.
It's at those long-end focal lengths that the VC system really makes a big difference. It was easy to achieve critically sharp handheld images when shooting in the 250-270mm range at 1/60 sec. I averaged 9 out of 10 sharp images at 1/30 sec—an impressive performance. I even managed to fire off a goodly percentage of critically sharp pictures of stationary subjects at 1/15 sec, validating Tamron's claim of up to four stops of vibration compensation.
As you would expect, image stabilization performance at shorter focal lengths is as good as or better than that, and we were able to capture surprisingly sharp pictures in the macro range, down to 19.3 inches or 1:3.5 magnification at the 270mm setting. It took us two tries to get an acceptably sharp portrait at about 20 inches at 270mm and 1/4 sec (!), and you may rest assured we never could have done it without turning on the VC.
Obviously the system is just as effective for shooting action pictures, but if the shutter speed you use is too slow you'll get motion blur even when the images are technically shake-effect free. Oh yes, the viewfinder image was commendably stable and shake-free as well.
Although there is a slight darkening of the viewfinder when you zoom to the longest focal lengths and the effective aperture is reduced to f/5.6-6.3 this did not pose any problems in composing the shot or manually focusing in outdoor or average indoor shooting situations. The f/6.3 minimum aperture at 270mm also did not prevent the Canon D40 from auto-focusing swiftly even in dim light, and with the excellent imaging performance of today's top DSLRs at ISO 400, 800 and even 1600 and beyond, having a relatively modest aperture at the longest focal lengths will seldom cramp your shooting style. In terms of sound output, the AF mechanism is as about average—not as quiet as some ultrasonic motor systems but hardly noisy enough to be objectionable.
A lens with flair...but not much flare
The Tamron 18-270mm VR comes with a flower-shaped lens hood that bayonets onto the front lens ring, positioning its longer light-blocking flanges at the top and bottom of the lens. It seems to do a reasonably good job in preventing sunlight from above from striking the front lens surface, but it's less effective in blocking sidelight, and the hood is not designed to be turned 90 degrees to position the longer flanges on the sides—if you try this it will fall off.
Fortunately, the lens is remarkably free of flare for a an 18-element, 13-group ultra-zoom and saturated flare-free images are the rule, even when shooting against the light—a performance similar to what we experienced with the Tamron 18-250mm. Evidently the multi-coating department at Tamron has some pretty good engineers and uses some pretty sophisticated manufacturing techniques, though the optical design plays a part in this as well.
In the not-too-distant past, extended range zooms were not noted for their stellar performance, especially in terms of linear distortion, flare control, and resolution at the longest focal lengths. Things have improved considerably in all these areas over the years and today consumers have a pretty wide choice of the high quality long-range zoom lenses at relatively moderate prices. However, in terms of sheer range, and real-world performance, the remarkable 15X Tamron 18-270mm VC MACRO is not only the world's longest-range interchangeable zoom lens for DSLRs, it's also one of the best.
Adorama price: $599.95
* Values given are for Nikon-mount cameras.