Sony FE 400mm F/2.8 GM OSS SEL400F28GM

This Sony prime is made for distant subjects. It fits Sony E mount and covers full frame. Wildlife specialists, outdoor sports shooters and news photographers are its natural users. A 400mm f/2.8 serves anyone who must work far from the action in fading light.

Sony introduced this lens in 2018. Its purpose comes from the 400mm focal length and f/2.8 aperture. It suits subjects that remain beyond the reach of a shorter lens from the same position.

The trade-offs are weight and a fixed focal length. Plan your position before the action starts. A wider lens helps when a large subject comes close or you want to show more of its surroundings.

The lens weighs 6 lb 6.1 oz (2895 g), with a body 14.13 in (359 mm) long and 6.22 in (158.1 mm) across. A monopod or tripod can take the load during long sessions. Check the support before releasing your grip.

There is no front screw-in filter thread. Instead, the lens has a drop-in holder for compatible filters. This lets you use filters without placing a large sheet in front of the glass.

At 400mm, a distant bird or athlete appears larger than with a shorter lens from the same position. How much of the frame it fills depends on its size and distance. If you cannot move, another lens or a later crop can change the framing.

The f/2.8 maximum aperture gives more room for a faster shutter speed or lower ISO than a smaller opening. That helps under floodlights or at dusk. Available light and the speed of a moving subject still determine the settings needed.

At close portrait distances, f/2.8 can give a thin zone of sharp focus. A background well behind the subject can become soft. Place focus on the eye that matters most, then stop down when several subjects at different distances must stay sharp.

Closest focus is 8.9 ft (270 cm), measured from the sensor. Anything nearer is too close to focus. That limit does not determine a suitable approach distance for wildlife. Leave animals enough space. Eleven aperture blades shape the opening as you stop down.

Image stabilisation is built in. It helps against camera shake in the viewfinder and in the frame at slow shutter speeds. For a running animal, a fast shutter still does the work, since stabilisation steadies the camera rather than the subject.

Dust and moisture resistance help during outdoor work. Use cover in persistent rain. A fluorine coating helps water and oily marks wipe away from the glass. Remove loose grit before cleaning after work beside a dusty track.

The optical design includes three fluorite elements and ED glass. These help reduce chromatic aberration, where different colours focus differently and leave fringes along high-contrast edges. Dark feathers against bright water are one place these fringes can appear. The component types explain part of the correction, without proving measured image quality.