This Sigma super-zoom is affectionately known in some circles as the "Bigma". And affectionately is the right word - people who have this lens like it, a lot. It's very solidly built, and delivers decent optical performance across an astonishing and unique range of focal lengths. (OK, performance tails off a bit at the long end, but only a bit.)

Like many lenses it performs best when stopped down a bit, and that- coupled with the lack of image stabilisation - means that a monopod or tripod is likely to be useful for shooting at the longer focal lengths. But despite that, it can't be denied that this lens offers a convenient, portable and affordable route to 500mm focal length.