What Digital Camera reviews the Tokina AT-X 17-35mm f/4 PRO FX to find out how it performs optically.
Tokina seems to be specialising in wideangle zooms, offering a variety of lenses for both APS-C and full-frame cameras at refreshingly affordable prices. The latest 17-35mm f/4 zoom, can be considered as a useful alternative to the company’s existing 16-28mm f/2.8 lens that was reviewed a few months ago. Potential buyers can therefore choose to have either a little more light-gathering power or a slightly wider zoom range.
The two lenses share a similar design except that the 17-35mm zoom is equipped with a filter thread (which the huge bulbous element of the 16-28mm lens prohibits). The lens barrel divides into thirds; the front section is occupied by a manual-focusing ring and the rear section is home to a similarly-sized zoom ring with a focused-distance window separating the two. Switching between AF and MF is carried out by pushing or pulling the manual-focusing ring. While this clutch mechanism ensures the focusing ring remains static in AF mode it also means there is no way of making manual adjustments without coming out of AF mode.
There is about 60° of rotation on the zoom ring and 80° on the focusing ring: both provide a firm grip and offer just the right amount of resistance. Overall build quality feels excellent and Tokina says there are sealing rings on all moving parts, as well as on the rear mounting flange, to protect against dust and dampness. Although such things should not matter, it is reassuring to see that this lens is manufactured in Japan.
It would be easy to criticise the zoom’s modest 2x focal-length range but its image quality immediately knocks this reservation into touch. There was no chromatic aberration at all visible at 17mm or 24mm and only the very slightest hint of colour (not enough to be called a fringe as such) at 35mm. Likewise, there was just the merest touch of barrel distortion at 35mm and a similarly insignificant amount of pincushion distortion at 17mm.
Technical testing revealed an excellent set of MTF curves that only dipped below the important 0.25 cycles-per-pixel threshold wide-open at 24mm and 35mm. Peak resolution exceeded 0.3 cycles-per-pixel and, more importantly, there was a consistent level of performance throughout almost the entire aperture range. This type of MTF performance has recently come to characterise the latest Nikon lenses and it is interesting to see the same sort of behaviour in a lens from another manufacturer.
The exceptionally wide angle-of-view on offer, coupled with minimal distortion, makes this lens a good choice for interiors and other situations where there is a need to cram a lot of content into a single frame. Real-world testing included covering a wedding in a small register office and the lens performed very well indeed, rendering images with a very natural appearance thanks to the aforementioned lack of distortion.
The only note of caution that needs to be sounded is the lens hood’s propensity to cast a shadow from inbuilt camera flashguns. Similarly, the lens hood definitely needs to be fitted for outdoor use, because if sunlight strikes the front of the lens there is a very real danger of degraded image contrast.
Despite all the strong points already mentioned, perhaps the best thing about this lens is its price. Although it has a list price of £830, the 17-35mm zoom can already be found online for just £600 – which is a bargain price for a lens of this quality. The only bad news is the fact that the lens is currently available in Canon and Nikon mounts alone. That aside, in view of its proven quality
and aggressive pricing, Tokina’s 17-35mm f/4 lens could well be one of the best super-wide zooms on the market today.
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