Sigma 70-300mm f/4-5.6 DG Macro £100, $140
It might be Cheap, but you get what you pay for
At only about a quarter of the price of Nikon’s most upmarket lens on test, this Sigma is a direct competitor in that it’s full-frame compatible and has the same zoom range. It also features a ‘macro’ facility that’s available in the 200-300mm part of the zoom range, something which is lacking in the Nikon lens. Selected via a switch on the lens barrel, this enables close-up manual and autofocusing while also limiting the zoom range, and increasing the magnification factor to as much as 0.5x. The same facility is available in the Sigma APO and Tamron AF lenses on test.
In other respects, however, it lags a long way behind the pricier Nikon lens. The autofocus system is driven by a basic and fairly noisy electric motor and there’s no optical stabilisation.
Levels of sharpness and contrast are okay overall, but disappoint when combining the longest zoom length with the widest aperture, which you might need to do in order to keep shutter speeds fast, especially in the absence of stabilisation.