Sigma 100-400mm F5-6.3 DG DN OS | Fujifilm X Fit

Sigma's smallest mirrorless ultra-telephoto zoom /

With optical performance and functionality that deliver professional-quality results, all packed into a lightweight and compact body, this versatile, long-telephoto zoom is the perfect option for both dedicated field photography and casual shooting. Its focal range is well suited to shooting fast-action subjects such as sports, wildlife and motorsport, but thanks to its portable body that weighs in at less than 1.2kg, its also ideal for telephoto landscapes and pet photography. Its even capable of macro-style close ups thanks to its maximum magnification ratio of 1:4.1. Optically the 100-400mm delivers outstanding sharpness right across the zoom range, with one FLD and four SLD elements that help to supress unwanted aberrations.

The lens is easily light enough for hand-holding, and Sigmas intelligent two-mode Optical Stabilizer helps reduce camera shake at slower shutter speeds. For those who prefer to use a tripod, a removable rubberised ring on the barrel allows a collar to be attached if desired (available separately). A range of other features including a focus limiter switch, custom modes, an AFL button, a lockable zoom ring and a dust- and splash-proof mount make the 100-400mm an extremely versatile option that can be used in a wide range of shooting conditions.

Outstanding build quality /

The exterior barrel of the 100-400mm is constructed using a polymer called Thermally Stable Composite (TSC). This has a similar thermal expansion rate to aluminium, meaning that the metal interior of the lens and the TSC exterior behave in the same way as temperatures change. TSC is also light and strong, and has a sleek finish for a premium look and feel. 

The lens has an internal focus mechanism as well as Dual Action Zoom, meaning its possible to zoom in and out accurately using the zoom ring, or very quickly simply by pushing or pulling the end of the barrel. The zoom ring is rubberised for easier operation, and it can be locked at various positions using the Lock switch.

Near the back of the lens is a rubber cover that can be removed to allow a tripod collar to be fitted (available separately). This makes for a more stable set-up if the lens is being used on a tripod.

The durable brass mount is surrounded by a rubber seal to help keep out dust and moisture.

Professional feature-set /

A range of controls on the lens include an AF/MF switch, an an AFL button that can be customised (depending on the camera body) to a range of different functions.

The lens also has a focus limiter so that the focusing range can be reduced for faster and more accurate operation. This is particularly useful when there are objects in the frame between the camera and the subject that the lens might attempt to focus on. 

The Optical Stabilizer switch offers a four-stop advantage and has a mode for general shooting and one for panning ideal for fast-moving birds and vehicles.

The lens has a stepping motor that delivers smooth, fast and accurate AF for both stills and video. It has been designed with lighter glass elements in the focus lens group, which ensures responsive autofocus that is fully compatible with all the latest AF camera technology.