When recently I needed a longer focal length for sport photography the question arose which lens?. It would be nice if money was no object and I could afford a lens by Nikon to compliment my D300, but hey, they do costa plenty!. So what now I thought, answer, start doing my research on lenses up to 400mm. After many hours of studying reports I decided that the Sigma 120-400mm f4.5-5.6 would suit my needs. I already owned lenses by Sigma and have found them to be good performers so why should this one be any different. So I bought one and shot off to my local racing circuit, Oulton Park, to try it out on fast moving racing motor cycles. What a great lens for this subject, with crisp clear images even at wide apertures. I shoot at speeds of 500 sec up to 1000sec with ISO's between 400-1000. Still great images!.
This lens is heavy and looks the part, but after a few hours of it hanging round my neck one certainly knows it's there. It has two levels of VR, (vibration reduction) which works really well, holding the image steady for long enough while the exposure is made, and when a bike is flying past at 140mph this is much appreciated. I've learned to only take the pic when the subject fills the frame, that way no image deterioration will take place as it does if an image needs cropping, resulting in lost pixels and loss of quality in the image. Was this lens a good buy?, you betcha it was, thank you very much Sigma.