The first constant aperture telephoto zoom in the Nikkor range is the 70-200mm f2.8VR, a lens which costs around £1200, weighs nearly 1.5kg and measures 215mm in length. It’s a monster. The Tokina 50-135mm f2.8, on the other hand, is £500 cheaper, weighs 600g less and is 80mm shorter.

True, the Tokina doesn’t have VR, and it doesn’t quite have the same range as the Nikon lens, but if you can get by without those two things, it’s a very compelling proposition.

Most zooms offer a decreased maximum aperture as the focal length increases. This forces you to use slower shutter speeds, right at the time when you actually need faster speeds to counter the increased risk of camera shake. Of course, you could invest in cheaper, image-stabilised lens (like the Nikkor 55-200mm VR) to take care of camera shake, but that only solves half the problem. Image stabilisers can prevent camera movement, but they can’t stop subject movement. Only higher shutter speeds can do that.

Reduced maximum apertures produce a dimmer viewfinder image. They make it more difficult to achieve the super-shallow depth of field effects that make telephoto shots stand out. And if you like to measure exposures manually, and then extrapolate through various shutter speed and aperture combinations, it means you have to keep rethinking the apertures available each time you change the focal length.

Constant aperture lenses are expensive to make, though, and amount of glass needed to maintain maximum aperture at maximum focal length makes them heavy too. So while the Tokina’s price and weight might seem steep compared to the average telephoto zoom, they’re actually very reasonable in this context.

It’s pretty compact, too. It’s heavy enough to overbalance a lighter SLR body like a D40/x and maybe even a D80, but it will balance better on a larger body like a Fujifilm S3/S5 Pro or a Nikon D200/300. However, this is an APS-C format lens, so it can’t be used on a full-frame Nikon film camera or the new D3.

The zoom and focusing rings are weighty but smooth. The focus ring has a sliding clutch mechanism which means you can quickly switch from auto to manual focus. Both the focusing and zooming are internal, so the length and even the weight balance of the lens don’t change. As a result, there’s no ‘zoom creep’ either if the camera is tilted downwards.

If any of this is sounding familiar, it’s because this is essentially the same as the Pentax 50-135mm lens reviewed in issue 64. But where the Pentax lens only fits Pentax cameras, the Tokina is available in Nikon and Canon mounts.

The optical properties proved similar too, despite the tests being carried out on two different bodies. At short and medium focal lengths, the resolution is high right through the aperture range. Only at maximum focal length does it start to tail off, and here you’ll need to stop down to f5.6 or f8 before the lens delivers its best performance.

The cost and weight mean this is a lens you should only consider if you need a fast short-medium telephoto for very specific types of work, but it would be perfect for any type of photography where you can get close to the action.

Final Verdict Too pricey, heavy and specialised to be an ‘occasional’ lens, but good if you shoot portraits or short-medium range action OVERALL

Our lens reviewer, and technical expert, Rod is a veritable photographic encyclopaedia. His illustrious CV has seen him write for many mags, websites and journals.