Sigma Imaging (UK) Ltd

	Digital Photographer - Issue 72 'On a non full-frame digital SLR, it equates roughly to a 240-800mm zoom. This makes it a super-telephoto, which is potentially perfect for capturing the most distant objects like jets at an air show, or pitched based sports where the player are often a long way from the touchline or boundary. The autofocus is fast and smooth, and Sigma’s HSM focusing system means that you also have full-time manual override…’

	Digital Camera Buyer - Issue 74 'As soon as you half-press the shutter release, the Sigma’s OS cuts in and visibly steadies the image in the viewfinder. The Sigma felt good in use. It was tested during a trip to the zoo and in a variety of conditions, and its magnifying power meant that it was possible to get some great animal portraits despite the distance between the visitors and the animals. The focusing was spot-on and the shutter speeds were usually high enough to prevent camera shake, with or without the OS.’

	Ephotozine - September 2008 'The build and handling of this lens is a considerable leap up from its predecessor and bears a strong resemblance in its construction to the well liked 50-500mm EX model. In terms of features versus value for money, this lens has to be the telephoto bargain of the century to date. With both a sonic focusing system and an optical stabilisation system, the two of which work well, coupled with a good optical performance and reasonably compact dimensions, I can see this optic finding a lot of suitors. If you want the pulling power of a 500mm in a manageable package, this one should be at the head of your compare list!’

	Which Digital Camera - October 2008 'The Optical Stabiliser (OS) as it’s known, utilises a system that has a floating element, which moves to counteract the camera’s movement. There are two modes that you can choose between: for still subjects pick mode 1; for moving subjects select mode 2.’ ‘In fact this lens is remarkably good, with sharp detail being maintained right into the edges of the frame at mid-aperture settings. When you look at the value for money element with this lens, it does a good job for the price.’

	Photography Monthly - October 2008 'The lens’ AF system uses Sigma’s Hypersonic Motor (HSM). This gives quick and silent operation comparable to what you’d expect from a Canon USM or Nikon SWM lens. Not everyone needs a long zoom like this, but if you’re into sports and nature, you could do far worse than this Sigma. Focus carefully and make sure your technique is good and you won’t be disappointed.’

	Outdoor Photography - Christmas 2008 'The OS, Sigma’s Optical Stabilisation seems just as effective as the Canon’s, and I managed to get sharp shots at around 100sec handheld, amazing for a 500mm.’ ‘The optical quality is astounding in this price bracket. Wide open at f/6.3 very sharp images are possible right up to 500mm improving even further at f/9.’ ‘Sigma’s APO design minimises colour aberration and fringing and three SLD glass elements and a rear focus system also help. These advances are responsible for the fine image quality, good contrast, little or no fringing and, in real world terms, images that ‘pop’.’ ‘In focusing speed it is close to the Canon 100-400mm and beats the Nikon 80-400mm hands down. …what I can say is that comparing the Sigma to my old Canon and Nikon left me feeling that both Canon and Nikon are well overdue on some serious work to refresh their nearest equivalent lenses!'

	British Journal of Photography - 7th January 2009 'Closer inspection shows a high standard of assembly for the optics, lens mount, switches and inner element mounting barrels. My expectations for the optical performance of both zooms were high. I was not disappointed, nor surprised to find the 120-400mm turning in a result marginally improving the high marks obtained for one of the finest Nikon zooms ever produced. Installation of a nine-bladed diaphragm in each lens produces well rounded defocused backgrounds with a smooth transition from unsharp through sharp to unsharp planes.’

	Birdwatch - March 2009 'The lens was a pleasure to use, as it was lightweight and easy to hold. I took a number of shots of both birds at different stages of the zoom range, all of which looked good on the screen. Colours, contrast and sharpness were far above what I would expect from a lens costing around £700. This lens will suit many photographers who are looking for a step up from their 70-300mm zoom, or indeed anyone who wants the extra reach that a 500mm will bring, and at very good value for money for the quality on offer.’

	Amateur Photographer - 28th March 2009 'Autofocus sound level is one of the lowest I’ve measured at 17dB over 35dB background. At 645 milliseconds, infinity to closest focus is really fast for a long zoom. As you would expect, this Sigma zoom lens gives the fully professional performance for which it has clearly been designed. Overall contrast is high, with crisp, fine detail at full aperture.’ ‘The lens succeeds in its of offering a state-of-the-art tool capable of delivering high-impact images in a variety of conditions. Stretching to a start point of 150mm rather than the usual 200mm of other long zoom lenses may perhaps give it a notional competitive edge.’

	Practical Photography - April 2009 'Covering 150-500mm is a great zoom range, especially when you factor in a digital crop factor like 1.6x found on our test camera, the Canon EOS 50D, as this takes the focal length range up to 240-800mm! Thankfully Sigma has added an optical stabiliser (OS) to the lens, which worked really well on our test shots. I found myself achieving near sharpness at just 1/30sec at 800mm – impressive stuff. The 150-500mm ticks all the right boxes for the photographer who wants lots of magnification in a quality lens with optical stabilisation.’

	PhotoPlus - September 2009 'As with the Sigma 120-400mm, the finish is excellent and the lens looks consummately professional. For sheer telephoto power coupled with superb optical quality and a highly effective image stabilising system, the recently launched Sigma 150-500mm is the lens to beat, and is streets ahead of the older 170-500mm lens that it replaces.’

	Digital Camera 'For starters, the zoom ring is smoother and easier to control, and this lens features a four-stop Optical Stabilizer, which worked every bit as well as the one on the 120-400mm. Other similarities include fast, quiet and extremely accurate HSM autofocus, complete with full-time manual focus override, and reassuringly rugged build quality. Using an all-but-identical configuration of groups, elements, SLD glass and multi-layer coatings as the Sigma 120-400mm lens, this larger model delivers similarly high levels of optical quality.’

	What Digital Camera 'The most important aspect of any modern long-focus lens – an efficient AF drive system – is also the Sigma superzoom’s forte. As well as being quick its motor is also quiet and acts internally, so the manual-focusing ring remains motionless but can still be used at any time to make adjustments.’