Sigma has released a 50-500mm f/5-6.3 zoom lens with image stabilisation (OS) and a Hyper Sonic Motor (HSM). Priced competitively at £1,399.99 the lens will undoubtedly appeal to wildlife and sports photographers.
Sony and Pentax versions of the lens are available, as are Nikon, Canon and Sigma fits, and any model with built in sensor shift can still utilise the lenses stabilisation. There's also four Special Low Dispersion elements to correct any colour aberration. With a weight of almost 2kg the 50-500mm will be a strain to use handheld, but as ever monopod/tripod support is midway down the lens on a rotatable arm.
More info can be found at: www.sigmaphoto.com