Tamron 18–200mm f/3.5-6.3 Di III VC for NEX: A Worthwhile Alternative
Tamron is the first third party manufacturer to produce an AF lens for Sony’s mirrorless cameras. Shridhar Kunte sees if the Tamron 18-200mm f/3.5-6.3 Di III VC is worth its price.
Tamron has had a very long history in making high power zoom lenses. Until recently, they had used this expertise for manufacturing lenses for APS-C sensor DSLRs and full frame cameras. With the introduction of 18-200mm f/3.5-6.3 Di III VC for NEX, the company has now taken a plunge into the growing lens market for mirrorless cameras. This will directly complete with Sony’s proprietary 18-200mm f/3.5-6.3 OSS lens. So, does the Tamron option provide anything new or worthwhile over Sony?
When mounted on a NEX camera, the lens gives an effective focal length of 27-300mm, in 35mm parlance. 17 elements have been arranged in 13 groups to round off a rather complex optical construction. This lens accepts 62mm filters and the front elements dose not rotate while focusing.
Throughout the entire focal length the lens has a focusing distance of 0.5m. At the telephoto end and minimum focusing distance, the magnification ratio is 1:3.7, which is quite decent. Hence, despite the fact that this is not a macro lens, it is really handy for shooting close-up photos.
Since mirrorless cameras adopt Contrast Detect AF, this 18-200mm lens incorporates a special stepping motor for focus drive. This combination achieves fast and silent focusing, which also makes this lens quite capable in terms of shooting video. For fine tuning focus, you can use the Direct Manual Focus (DMF) function, which allows the user to override and make fine adjustments even after the AF is locked on to subject.
Tamron has completely revamped the VC mechanism. In previous lenses, the VC unit used heavy magnets that would move, but they have now been replaced by a lightweight three-coil system. This reduces the overall size and weight, which is a huge advantage, especially considering that this is a mirrorless lens. Since the power for stabilisation is drawn from the camera, I am curious to see if the new VC mechanism saves battery life, though that will be known only after a direct comparison with Sony’s OSS version of image stabilisation.
The lens is well built and feels solid. The exterior is finished with brushed aluminium and high grade plastic, which is covered with rubber for a more secure grip. The broad, rubberised zoom ring operates very smoothly and offers just the right amount of resistance for a comfortable zooming action. To take care of lens creep, there is a switch that locks the zoom position. The manual focusing ring is behind the zoom ring, which is unconventional. On a NEX-5 body, the balance is perfect when the lens is as the wide end. However, as one zooms in, the lens’ length extends and the combination becomes somewhat uncomfortable. A flower-shaped hood locks on tightly and extends far, thus helping eliminate stray rays from the sun or other lights.
Focusing is quick and accurate, but at the telephoto end, it really suffers. The camera often loses focus and takes a long time to lock on. At the widest aperture, the lens exhibits slight softness, but gains sharpness when stopped down. The best results are at f/8 in the middle of the zoom range and at f/11, when shooting at the telephoto end. Contrast drops in photos taken against the light. Chromatic aberration, while not prominent, is apparent at the corners of the frame.
The seven-bladed aperture construction gives decent bokeh at the telephoto end. Barrel distortion is apparent at the wide end, but this is expected for a lens of this nature, and is overall, well controlled.
This Tamron lens is a solid overall performer. The wide focal length range covered by this lens is definitely its strongest asset. While it offers an excellent range for travel enthusiasts, action photographers may want to give this lens a miss because of its slow maximum aperture and sluggish AF performance at the telephoto end. The Tamron lens is smaller and lighter than its Sony counterpart. However, my concern is that its price, at Rs. 49,000, is almost identical to that of the Sony. If it is more aggressively priced and shows a better market presence, it is bound to lure Sony users.
Useful coverage from wide to telephoto, VC
Sharp at the middle apertures, flare well controlled, sluggish AF at the tele end
Feels solid and sturdy
Zoom creep prevention switch, slightly imbalanced, lightweight
Warranty & Support
Value For Money: 3/5 stars
Who Should Buy It?
Any NEX user who wants agood, lightweight, do-it-all lens.
The Tamron 18-200mm VC is lighter than otherstabilised superzoom lenses and also delivers on quality.