Sigma 100-400mm F/5-6.3 DG DN OS | C

This Sigma telephoto zoom covers 100–400mm. Separate versions fit Fujifilm X, Leica L and Sony E cameras. Choose the mount that matches your camera. Sigma introduced the L and Sony E versions in 2020, then added Fujifilm X in 2023.

The Fujifilm X version fits APS-C cameras. The L and Sony E versions cover full-frame sensors. The range suits wildlife, outdoor sport and distant details. You can change framing as action moves without changing lenses. The main trade-off is light gathering: the maximum aperture narrows from f/5 to f/6.3 across the zoom.

Bright conditions help when moving subjects need a fast shutter speed. In shade or fading light, you may need a higher ISO.

The Fujifilm X version weighs 2 lb 8 oz (1135 g) with its protective cover. It measures 7.85 in (199.5 mm) long and 3.39 in (86 mm) across. Other mounts differ in weight and length. Screw-in filters must match the 67mm front thread to attach directly.

At 400mm, a distant bird or player appears larger than at 100mm from the same position. How much of the frame it fills still depends on distance. The shorter setting helps you locate moving action before tightening the framing. A large nearby subject may need a wider lens.

The maximum aperture changes from f/5 to f/6.3 as you zoom. A close subject can still have a soft background at the long end when there is enough space behind it. Branches directly behind an animal may remain distracting. Change viewpoint when the location allows.

Closest focus is 3.7 ft (112 cm) at 100mm, measured from the sensor. The minimum distance is longer at 400mm. Maximum magnification reaches 0.24x at the long end, useful for larger details. These limits do not determine a suitable approach distance for wildlife. Leave animals enough space.

Optical stabilization reduces camera shake and steadies the view at long settings. It helps with still subjects at slower shutter speeds. A flying bird still needs enough shutter speed for its movement. Firm support remains useful for long waits and slow exposures.

The zoom lock holds the barrel at its shortest setting for transport. Release it before changing focal length. You can turn the zoom ring or use a push-pull action to change framing. Keep the lens supported when carrying the camera between locations.

A seal at the mount helps keep dust and moisture out at that connection. This protection does not extend throughout the barrel. Use cover in rain and keep the camera connection clean when changing lenses.

One FLD element and four SLD elements help reduce coloured fringes along high-contrast edges, such as a dark wing against bright sky. These glass types form part of the optical correction; their presence alone does not establish measured image quality.