Sigma 120-300mm f/2.8 EX DG OS HSM £2499.99
1st Mar 2012 | 12:06
An affordable telephoto lens for Canon, Nikon and Sigma DSLRs
High-quality telephoto lenses for DSLRs are tricky to buy. They're a huge investment, with prices starting at around £1,500 and heading sharply skywards. There are also considerable usability problems: long focal lengths require fast shutter speeds, which require large apertures, which all results in lots of heavy, fine-tuned and extremely expensive glass.
The Sigma 120-300mm f/2.8 EX DG OS HSM is a cheaper option than Nikon and Canon's astronomically expensive (although superb) pro lenses. We got ours from Warehouse Express, where you can pick one up with a three-year warranty for £2,099 in the UK. In the US they're priced at around $3,199 - far cheaper than a 300mm f/2.8 lens from Nikon or Canon. But is it any good?
The new Sigma 120-300mm f/2.8 EX DG OS HSM replaces Sigma's older, almost-identically specified lens. With the new model you get optical stabilisation (OS), and the whole thing adds up to a lens that is far from a lightweight.
It's heavier, for instance, than the Canon 300mm f/2.8 prime lens by nearly 600g, which isn't exactly a welterweight at 2.4kg. The Sigma is twice as heavy as the Canon 100-400mm f/5.6, although in fairness it's also two stops faster at its telephoto end.
Can you shoot with the Sigma 120-300mm f/2.8 EX DG OS HSM handheld? Just about, but don't expect to be able to train it on a subject for particularly long - a monopod is important unless you want aching arms. Attach it to a support and it feels well-balanced and easy to manoeuvre.
Build quality and performance
The good news is that image quality is superb. The Sigma drops off in sharpness towards the smaller end of its aperture range. F/16 and smaller can be tricky, but since most will be using it at f/8 and bigger in the name of getting usable shutter speeds, avoiding the softer reaches of the aperture range is pretty easily done.
In particular, f/4 and f/5.6 are extremely sharp, whether you're inspecting an image in the centre of the frame or the corner. It's at its sharpest at f/5.6, although smaller apertures are by no means disastrous.
For those looking to exploit the light-gathering potential of f/2.8, we found the Sigma telephoto lens to be consistently sharp across the frame, albeit with a little light fall-off in the corners at its widest focal length of 120mm.
There's a touch less margin for error when the lens is zoomed in, with images a little softer, but f/5.6 - if you've got the light or ISO performance for it - is still very good indeed. There's more good news when it comes to chromatic aberration - namely that we struggled to spot any.
The Sigma 120-300mm f/2.8 EX DG OS HSM offers an all-round convincing performance when it comes to good-looking images - certainly good enough for keen wildlife and sport snappers, assuming you can fit it in your hand luggage. It also produces images with decent levels of contrast, which makes processing your pictures quicker.
There's a more-than capable optical stabilisation system in place as well. It offers plenty of traction to compensate for wobbly hand-holding - a good thing considering the weight. On a monopod we were able to get steady shots at 1/125th of a second and very slightly slower at 300mm, so it'll give you around three stops of extra shutter speed in most situations.
Usefully, the OS switch on the barrel of the lens has three positions - you can turn it off entirely, or you can set it to only correct vibrations vertically, which is useful if you're taking panning shots.
The autofocus system is effective - perhaps a shade slower than on more expensive lenses, but give the autofocus button on your camera a prod and it responds nicely. It's an internal autofocus mechanism as well, and is next to silent.
Inevitably, there are compromises. The focus and zoom rings are very stiff - admittedly there's a lot of glass to shuffle about, but it can mean that making minute framing adjustments is a bit hit and miss.
That said, there are no complaints about build quality - the body of the lens is made from tough-feeling metal that feels like it will be able to take the odd knock. The only real complaint is the hood, which is made from less-than-bulletproof-feeling plastic. This feels like it will take less abuse than Canon's (much more expensive) carbon fibre hoods.
Those shooting in particularly extreme environments will note the weather proofing, although this doesn't extend to the lens mount, which lacks a rubber seal to stop water creeping in between the lens and the camera body. Short of dunking it in a pond, though, you're unlikely to need to worry about this even in light rain.
We're not over-keen on the Sigma 120-300mm f/2.8 EX DG OS HSM's tripod mount. It certainly doesn't feel like it's going to come off, but with the clamp loosened to enable the lens to rotate without leaving your monopod there's a little give between the ring the foot is mounted on and the main body of the lens.
The give is there so that the foot can be removed entirely from the lens, but given the lens's weight, and the usefulness of the foot as a carry handle, it might have been better if the foot was permanently attached, as it is, say, on Canon's 500mm f/4.
Taken at 120mm
Taken at 300mm
120-300mm is a useful focal length range for wildlife and sport photography
A wide maximum aperture means you can use high shutter speeds without having to push the sensitivity too far.
The Sigma 120-300mm f/2.8 EX DG OS HSM is a cracking piece of kit. At the apertures it's most likely to be used at it's very sharp, autofocuses quickly and offers the kind of sterling build quality you need from a lens that's likely to spend most of its working life outside.
The telephoto lens is made from durable, sturdy metal and has decent weatherproofing for outdoor shooting. Image quality is also excellent, particularly at wider apertures and using the built-in impressive optical stabilisation.
The waterproofing falls down in the lens's lack of a rubber seal on the lens mount, and parts of the lens are tricky to manouvre at times.
The big maximum aperture undoubtedly makes it a more unwieldy lens, which isn't particularly welcome news, but that will often make the difference between a comfortable shutter speed and one that produces wobbly shots. The Sigma 120-300mm f/2.8 EX DG OS HSM is well worth a look.