Big Test
When we say Big Test, we mean Mammoth Test, with our review of eight super-sized telephoto zoom lenses
Forget all that ‘less is more’ bunkum. Take a step up from a budget 55-200mm or 70-300mm telephoto zoom lens and you can literally hit the big time.
One option is to stick with a modest maximum focal length but to go for a faster aperture. One of the Sigma lenses in this group test is unique in combining a 120-300mm zoom range with a wide f/2.8 aperture that remains constant throughout its zoom range. It’s like shifting up a gear from a standard 70-200mm f/2.8 lens, grabbing extra reach without losing an f/stop. That’s great news for keeping shutter speeds fast in dull lighting, and for minimising depth of field.
Another option, which we covered back in issue 29, is to buy a good-quality 70-200mm f/2.8 lens and supplement it with a 1.4x or 2x teleconverter. This gives you a maximum focal length of 280mm or 400mm respectively, with a drop in widest available aperture to f/4 or f/5.6. This time, however, we’re concentrating on big lenses that do the job on their own.
The Sigma 120-300mm is extrahefty, thanks to its combination of 300mm focal length and wide f/2.8 aperture, and while the other lenses on test are also bulky – in order to accommodate that extra-long, super-telephoto reach – they are smaller and lighter than the Sigma. This is because the narrower widest aperture enables the front element, and therefore the overall diameter of the lens, to be smaller. This is true of most of the variable-aperture lenses on test, which generally start off at f/5 at the short end of the zoom range, and shrink to f/5.6 or f/6.3 at the longest end.
The maximum focal length of most lenses in this test group is between 400mm and 600mm. The zoom range is more generous in some cases than others, ranging from two times in the Nikon 200400mm lens to 10 times in the Sigma 50-500mm. To give extra reach, new contenders include the Sigma and Tamron 150-600mm lenses. Going further still, the gigantic Sigma 300-800mm gives class-leading telephoto reach, but measures more than half a metre long and weighs nearly 6kg! By contrast, the Nikon 80-400mm and Sigma 150-500mm lenses are relative lightweights, at just 1.57kg and 1.78kg respectively.
Typically, constant-aperture telephoto zooms retain a fixed physical length. With variableaperture designs, the overall length of the lens can nearly double when you zoom from the shortest to the longest focal length. What looks like a manageable proposition in the box can quickly trombone into something unwieldy. These lenses typically also have an expansive girth; some have oversized filter/ accessory attachment threads of 95mm or even 105mm, making filters very costly. Others have no option for front-mounted filters at all, instead offering the facility for ‘drop-in’ filters of 46mm or 52mm in diameter, mounted near the rear of the lens (see comparison table, page 108, for details).