SUPER MODEL
TAMRON SAYS IT’S USING A NEW SEALANT MATERIAL WHICH IS APPLIED IN ALL THE JOINTS TO PROVIDE MORE EFFECTIVE PROTECTION AGAINST THE ELEMENTS.
Along with the 24-70mm f2.8, the 70-200mm f2.8 is a staple of any serious photographer’s kit. Together they span a focal range that takes in a wide variety of subjects and the constant aperture of f2.8 actually provides plenty of flexibility when it comes to low light situations or reducing depth-of-field.
Not surprisingly then, the D-SLR makers pride themselves on their 70-200mm f2.8 zooms and there have been regular upgrades to incorporate new features – such as optical image stabilisation and weather-proofing – and improved optical designs utilising the latest materials and manufacturing techniques. Nikon, for example, has only just recently introduced its third-generation model boasting numerous performance enhancements and a more compact, lighter weight design. The ‘independents’ too have recognised the importance of having a high-performance 70- 200mm f2.8 in the range – often with a price advantage over the camera brands – and Tamron has just upped the ante with its all-new ‘Generation 2’ – G2, for short – model. The previous version, by the way, has been around since 2012 and a bit has happened in lens design and technology since then.
The ‘official’ model name is the Tamron SP 70-200mm f2.8 Di VC USD G2 – so it’s perhaps not surprising there’s a far simpler Model A025 designation for those that need it.
Nikon has raised the bar with its latest f2.8 speed 70-200mm high performance zoom, but Tamron’s new G2 model reveals it clearly relishes a challenge.
TO THE LETTER
As with most accessory lenses, it’s all those initials in the model name which tell the story. Of course, Tamron has been using the ‘SP’ prefix on its higher-end lenses for decades (it stands for ‘Super Performance’, by the way) and the G2 model has an all-new optical design, incorporating a range of
current technologies to deliver a range of improvements to imaging performance.
The optical construction comprises 23 elements in 17 groups with five of these elements being low dispersion (LD) types and one being an XLD type… which signifies ‘eXtra Low Dispersion’ characteristics. These special elements work to minimise chromatic aberrations – or colour fringing – by limiting the amount of dispersion between the different coloured wavelengths of light as they are refracted. Chromatic aberrations can be particularly problematic with fast telephoto lenses and Tamron’s design is intended to be effective across the lens’s focal range which is always a challenge.
Tamron’s latest’s ‘eBAND’ anti-reflection coating is applied to element surfaces – the name is short for ‘Extended Bandwidth And Angular-Dependency’ – and its special nano-structure layer has an extremely low refractive index to further assist with the minimising of ghosting and flare. The zoom’s focusing group is internal – so the front element doesn’t rotate – and changes made to the designs of both the focusing and zooming cams reduce the minimum focusing distance by quite a bit to 95 centimetres which, at 200mm, gives a maximum magnification ratio of 1:6.1. For the record, the previous model only focused down to 1.3 metres. Autofocusing is via Tamron’s latest version of its ‘Ultrasonic Silent Drive’ – that’s the USD initials in the model name – which is controlled via two processors and a new algorithm to optimise speed without compromising accuracy. It’s a ring-type drive which provides a full-time manual override for fine-tuning. For even faster AF operations, there’s a limiter switch which can be set to lock out the closest distances from three metres to the minimum object distance. Incidentally, this range can be changed using the optional ‘Tap-In Console’ which is a USB dock enabling various adjustments and firmware upgrades.
STEADY UP
Also new-and-improved is the optical image stabiliser. Tamron uses the name ‘Vibration Compensation’ (VC for short) and it now delivers up to five stops of correction for camera shake which is currently the highest provided on any pro-level f2.8 speed 70-200mm zoom. There are three image stabiliser modes for general shooting, for panning (with the lens detecting the orientation) and for engaging only during an exposure rather than also when viewfinding.
The A025’s optical design has been optimised for use with Tamron’s new teleconverters – the 1.4x Model TC-X14 and the 2.0x Model TC-X20 – which increase the focal range to 100-280mm (with a maximum aperture of f4.0) and 140-400mm (f5.6) respectively. Full autofocusing capabilities are retained.
While primarily designed for use with full-35mm format sensors (Tamron uses the designation ‘Di’), this lens can be used on ‘APS-C’ format D-SLRs where the effective focal length becomes 105-300mm (at 1.5x) or 112-320 (at 1.6x).
The G2 70-200mm f2.8 is currently available in the Canon EF and Nikon F mounts, the latter being the G-Type configuration so aperture selection is controlled from the camera body. This is now standard across Nikon’s D-SLR line-up, but will preclude the Tamron’s use on many older digital bodies from around mid-2007 or earlier (and all 35mm film bodies). However, using the G-Type mount has enabled Tamron to adopt an electromagnetically-controlled diaphragm in its Nikon model and this allows for more accurate aperture setting – especially frameto-frame with continuous shooting. Incidentally, the aperture range in both versions is from f2.8 to f22 and the diaphragm itself employs nine blades to give smoother outof-focus effects.
IN THE HAND
In terms of its physical construction the new Tamron 70-200mm f2.8 zoom employs metal barrel tubes with full sealing against the intrusion of dust or moisture. Tamron says it’s using a new sealant material which is applied in all the joints to provide more effective protection against the elements. A very substantial gasket protects the lens mount.
Additionally, a fluorine coating is used on the exposed surface of the front element to help repel both water and grease, and allow for easier wiping down. Should you prefer to fit a protective filter, the screwthread diameter fitting is 77 millimetres. A bayonet-fit petaltype lens hood is supplied.
As is standard in this class, a rotatable tripod mounting collar is provided and it’s made from magnesium alloy to help save weight. More interesting though, is that the quick-release plate is an Arca-Swiss type, thereby providing compatibility with a wide selection of pro-grade tripod heads.
The new lens’s styling has been modernised so, for example, the tripod mount’s collar is flushfitting as is the manual focusing collar and a matte black finish give the whole lens a very clean and contemporary look. In the hand it feels very strongly built and all the barrel-mounted switches (for the AF limiter, VC on/off, stabiliser modes and AF/MF) have a crisp, positive action. The focusing collar is electromagnetically controlled (rather than being mechanical) so it’s smooth in its operation, but has that slightly disconnected feel which is a characteristic of these controls and, of course, there are no stops. The zooming collar, on the other hand, feels nicely meaty and covers the full focal range in slightly less than 90-degrees twist.
PERFORMANCE
Tamron’s claims regarding the improved imaging performance of its G2 70-200mm f2.8 are no idle boast. The centre-to-corner sharpness is exceptional across the focal range up to f11 and even at the widest aperture of f2.8. Diffraction comes into play at f16 and f22 so corner sharpness suffers a little, but it’s still pretty good and the centre sharpness remains very good.
In terms of its sharpness, the new lens is easily superior to the previous model and on a par with Nikon’s rather more pricier thirdgen AF-S 70-200mm f2.8 which, of course, we tested in the March/ April 2017 issue. The Tamron lens even exhibits Nikon-esque contrast characteristics which result in nicely punchy images with beautifully crisp definition.
There’s minimal vignetting (brightness fall-off) when shooting wide-open too, and the correction for lateral chromatic aberrations is very effective across the focal range, including when shooting at the wider apertures. It’s nonexistent in the centre of the frame, and only occurs near the corners along very high contrast edges, but it’s only very minor, suggesting that all those low-dispersion elements are doing their job very well.
Distortion is also well controlled with slight barrel-type bending at 70mm which becomes slight pincushion-type bending at 100mm, but stays absolutely negligible up to 200mm so it really isn’t noticeable at all, which is
impressive. Flare is very effectively suppressed and, even in strongly back-lit situations, the contrast and colour are still very good.
We tested a Nikon mount version of the Tamron G2 70200mm and used it on a variety of Nikon D-SLRs, both full-35mm and ‘APS-C’ models. Autofocusing operation was flawless on them all and certainly on a par with the speeds we’d experienced with Nikon’s own lens, including when tracking high-speed subjects.
The new VC optical image stabilisation does indeed deliver up to five stops of correction so we were able to obtain pin-sharp results when shooting hand-held at 200mm with a shutter speed of just 1/6 second. In lower light situations this means being able to keep using a lower ISO setting rather than dialling up the sensitivity and thereby increasing the effects of noise reduction processing.
THE VERDICT
Tamron’s profile in Australia has suffered a little recently as the result of the unfortunate demise of two distributors in quick succession, but it’s now in the capable hands of Blonde Robot, and new products like the SP 70200mm f2.8 G2 zoom will certainly also help re-attract attention.
The comprehensive G2 upgrade has covered all aspects of the new lens’s design, handling, capabilities and performance; making it a serious competitor to the models from camera brands and independent rival Sigma. Along with Nikon’s latest model, it benefits greatly from utilising the latest optical technologies and manufacturing processes. In comparison, a couple of competitors are starting to get a bit long in the tooth.
The Tamron lens is beautifully made and handles very comfortably with both the bigger pro-level D-SLRs and on more compact bodies. And while this may be purely cosmetic, it looks smart too.
But the big deal is the performance or, more specifically, the performance-for-the-price. Given how close it is to the latest Nikon lens in terms of both sharpness and the high levels of correction for aberrations, the actual price difference here is a significant consideration. With the SP 70-200mm f2.8 G2, Tamron is back on the enthusiast photographer’s radar.
TAMRON’S CLAIMS REGARDING THE IMPROVED IMAGING PERFORMANCE OF ITS G2 70-200MM F2.8 ARE NO IDLE BOAST.