Optical image stabilisation Macro functionality Hyper-Sonic AF Motor The Sigma 17-70mm f/2.8-4 DC Macro OS HSM covers a wide to standard focal length making it perfect for landscape and portrait imagery, and is intended for use on an APS-C DSLR such as the Nikon D5100. The excellent value for money makes this lens a recommended choice for newcomers, with the Nikon 16-85mm being a similar price but missing out on the macro functionality and offering a less bright aperture. Being able to focus within 22cm allows for the likes of insects or flowers to be shot in incredible detail, and thanks to the optical stabilisation longer shutter speeds can be used, with the Hyper-Sonic Motor providing a quick, quiet focus method.