Full Test: Tamron 18-400mm lens
Superzoom meets super-telephoto in Tamron’s latest ‘megazoom’ lens, with a 22.2x range to really go the distance
Superzoom? Megazoom? Whatever you call it, does this all-in-one zoom really deliver?
tamron has a history of pushing the envelope in superzoom lens design. For sheer zoom range, its 18-250mm, 18-270mm and 16-300mm were all world-beaters when launched, and this new 18-400mm lens follows suit. The unprecedented 400mm telephoto reach is equivalent to a stonking 640mm in full-frame terms, when the lens is on a 1.6x crop-sensor Canon like the EOS 800D or 80D.
It’s delivered from a surprisingly compact and lightweight package (710g), but even so the new lens is about 30 per cent heavier than Tamron’s 16-300mm superzoom. While you get an extra 100mm of focal length at the long end, you lose 2mm at the short end.
That might not sound like much, but the reduction in wide-angle potential is very noticeable, shrinking from 82 degrees to 75 degrees. The optical path includes two moulded glass aspherical elements and one hybrid aspherical element, along with three low-dispersion elements. The combination helps to rein in the physical size, while optimizing image quality in terms of sharpness, contrast and colour fringing.
Autofocus is driven by an HLD (High/low torque-modulated Drive) motor. It’s very quiet in operation, similar to a ring-type ultrasonic system, yet able to adjust focusing speed for speedy stills performance and smooth transitions in movie capture. A retrograde step, compared with the Tamron 16-300mm lens, is that the focus ring rotates during autofocus and doesn’t enable full-time manual override. There’s also no focus distance scale. At least the ring is sufficiently far forward that its spinning doesn’t impair handling.
Tamron’s proprietary VC (Vibration Compensation) image stabilization is featured, with a rating of 2.5-stop efficiency. That’s rather less than in some of Tamron’s other recent lenses, but still very much worth having.
Build quality is good, with a sturdy feel and negligible flexing in the three-part extending barrels. The zoom ring is quite stiff but zoom creep is fairly minimal, even when shooting at near-vertical angles. The overall construction is moisture-resistant with a number of weather seals, including one around the metal mounting plate.
performance
Tamron has succeeded in the considerable technical challenge of maintaining good sharpness throughout a huge zoom range, right up to the ultra-long 400mm focal length. In our lab tests, the lens proved as sharp at its longest setting as the competing Sigma 18-300mm and Tamron 16-300mm lenses, despite giving considerable extra reach.
Typical of superzoom lenses, barrel distortion at the shortest zoom setting is clearly visible, but it’s rather less extreme than the Tamron 16-300mm. Colour fringing is noticeable, especially at long zoom settings where it’s very similar to the Tamron 16-300mm. Overall, the new Tamron’s huge zoom range doesn’t come at the cost of a greater compromise in image quality compared to other superzooms.