The Tokina AT-X Pro 11-16mm f/2.8 Aspherical (IF) DX is a wide-angle zoom with a fixed aperture and plenty of promise
With the equivalent full-frame coverage of a 17-24mm lens, Tokinas APS-C 11-16mm zoom offers a very wide angle-of-view but a rather restricted 1.5x zoom range. Those are the headline figures but they don’t tell the whole story. The maximum aperture is a constant f/2.8, which makes this an impressively bright lens at all focal-lengths: equally impressive is the zooms freedom from distortion, both barrel and pin-cushion.
The lens feels solid and well-made. There is a broad focussing ring towards the front of the lens and a narrower zoom ring behind with a focussed-distance window in between the two. Switching between automatic and manual focussing is achieved using a push/pull action on the focussing ring. This method is a Tokina hallmark and is highly intuitive: the only drawback is a lack of manual intervention in AF mode.
Wide-aperture, wide-angle lenses such as this are particularly prone to suffering from spherical aberration, whereby rays that strike the lens at different distances from the optical axis come to a focus at slightly different distances to the rear. The solution to this problem is to be found in non-spherical (aspherical) lens profiles.
Tokina has an association with Hoya that allows it to offer what it claims are: high quality precision moulded all-glass elements with a greater aspherical shape than any other lens manufacturer. The practical result ought to be greater sharpness right across the image field.
Technical testing confirms that, at its best, Tokinas lens does indeed deliver excellent sharpness. Maximum resolution is better than 0.3 cycles per pixel, which is extremely impressive for a lens of this sort. Admittedly, wide-open performance at the shortest focal-length is disappointing but the zooms excellent peak-resolution figures, which fall across the range of commonly-used aperture settings, go some way towards off-setting this weakness.
There were also clear signs of chromatic aberration on high-contrast technical images but no technical problems were spotted when the lens was used for real-life photography. That said, f/2.8 was avoided whenever possible: this was partly because of its expected softness but more importantly because the lens works best when stopped down for pictorial rather than technical reasons.
In particular, Tokinas 11-16mm zoom excels in its ability to convey a lovely three-dimensional feel when used at close range thanks to a very generous depth-of-field and smooth transitions from in-focus areas to softer parts of the picture. The fact that there is no visible distortion means the lens can also be used with great success to capture cramped interiors with an amazing sense of space.
Given that the zoom range offered by Tokina's 11-16mm lens is just 1.5x it is perhaps best to think of this as a prime lens that simply features a small amount of focal-length adjustment. Potential buyers who want a wider zoom range might turn instead to Tokina's 12-24mm, which is less costly but is restricted to an f/4 maximum aperture. But for maximum speed and the widest angle-of-view, the 11-16mm zoom is worthy of very serious consideration.