Tokina AT-X 11-20mm f/2.8 Pro DX
£499/$599 Fast and constant, Tokina’s latest wide-angle zoom for DX format SLRS gets it right in the majority of the places
Tokina has a strong tradition in wide-angle zooms, its popular 11-16mm lens for DX format cameras dating all the way back to 2008. A Mk II edition was launched in 2013, adding an autofocus motor to enable autofocus with Nikon D40, D3xxx and D5xxx series cameras. This 11-20mm goes further, quite literally, by extending the overall zoom range while still maintaining a constant-aperture design, delivering f/2.8 at all focal lengths.
One of the things that made the original 11-16mm lens so popular was its
combination of sturdy build quality and good optical performance at an attractive selling price. The 11-20mm feels similarly robust, and features a weather-seal ring on its mounting plate, as fitted to the Nikon 10-24mm DX lens. The Tokina certainly has better build quality than Nikon’s newer, lightweight 10-20mm DX lens, which has a plastic mounting plate and feels rather flimsy by comparison. However, the Tokina lacks the budget Nikon lens’s optical stabilization.
An up-market optical design includes two all-glass moulded elements and three SD (Super-low Dispersion) elements. At 560g, the Tokina is nearly two and a half times heavier than the Nikon 10-20mm. This is partly because of the metal rather than plastic mounting plate, but also due to the forward optical elements having a much larger diameter, to enable the f/2.8 aperture compared with the Nikon’s f/4.5-5.6 variable rating. As such, the filter thread is also larger, at 82mm compared with the Nikon’s 72mm.
Nikon’s 10-24mm lens has a fast and very quiet ring-type ultrasonic autofocus system with full-time manual override. The 10-20mm lens has a stepping motor system, which is also quick and quiet, and enables override of autofocus with an electronically coupled ‘fly-by-wire’ focus ring. By contrast, the Tokina has a more basic electric motor with the company’s trademark ‘One-touch Focus Clutch Mechanism’. This enables you to switch
between autofocus and manual focus by snapping the focus ring forward or backward respectively. Some love it, some hate it. Either way, you need to be careful not to nudge the ring accidentally, inadvertently switching between auto and manual focusing. On balance, we prefer the full-time manual override facilities of the Nikon lenses.
Performance
The Tokina is impressively sharp, even when shooting wide-open at f/2.8, at the short end of the zoom range. During our tests, however, sharpness was let down by inconsistent autofocus accuracy. The autofocus system is reasonably quick considering it’s based on an electric motor, but is still rather noisier than in current competing Nikon, Sigma and Tamron lenses. Levels of colour fringing are fairly typical for this type of lens, but distortion is particularly negligible at the long end of the zoom range.