It’s the mark of a maturing lens system when the prime supertelephotos start appearing, so the 400mm f2.8 is an important new arrival for Sony’s rapidly expanding FE mount line-up.

It’s the first large-aperture supertelephoto prime in the FE mount line-up and also, right now, the lightest model in its class. Sony last fast supertelphoto prime was a 500mm f4.0 in the A mount. Obviously, Sony is continuing to target sports, action and wildlife photographers as converts to its full-35mm format mirrorless camera system, with this lens being an obvious companion for the high-speed A9 (a new firmware upgrade for this body ensures full compatibility with the 400mm lens).

Photo: Sony

The new FE 400mm f2.8 GM OSS – to give it its full model name – employs magnesium alloy barrel tubes with fill sealing against the intrusion of dust and moisture. Additionally, the exposed surface of the front element has a fluorine coating to help better repel dirt and water. The supplied lens hood is made from carbonfibre to help minimise weight. The 400mm f2.9 weighs 2.895 kilograms – which is significantly lighter than its D-SLR rivals from Canon and Nikon – and is just under 40 centimetres in length. A rear filter slot accepts 40.5 mm diameter screwthread types, including a circular polariser (the VF-DCPL1) which will be available later in the year. External controls include four customisable focus-hold buttons which can also be programmed to activate other features such as Sony’s ‘Eye AF’ function. There’s also a switch for engaging the ‘Full-Time DMF’ function which provides an instant manual focus override, and a programmable function ring.

On the inside, the optical construction comprises 23 elements in 17 groups, including three fluorite types to minimise both axial and lateral chromatic aberrations. Sony’s ‘Nano AR’ multi-coating is used to minimise internal reflections and reduce the occurrence of ghosting or flare. Importantly, the optical construction has been designed to move the lens’s centre-of-gravity more towards the rear so it’s better balanced with the lighter-weight Sony mirrorless camera bodies, rather than being front-heavy which is often the case with supertelephotos.

Photo: Sony

The FE 400mm f2.8 has optical stabilisation with the choice of three operating modes and which includes a new Mode 3 setting with employs an advanced algorithm to enable easier framing when tracking moving subjects. Five axis image stabilisation is available when the lens is used on a Sony camera with in-body image stabilisation.

The lens’s diaphragm employs 11 blades to give a more uniformly circular aperture and hence very smooth out-of-focus effects. Autofocusing is performed via a newly-developed ‘XD’ (Extreme Dynamic) drive which employs high-efficiency linear motors to give faster adjustments and, according to Sony, up to a five times improvement in the subject tracking performance. New motion algorithms are said to minimise both lag and instability while also reducing AF noise. The new 400mm is compatible with both the 1.4x and 2.0x E mount teleconverters which give a 560mm (f4.0) and 800mm (f5.6) focal length respectively.

Sony’s FE 400mm f2.8 GM OSS supertelphoto lens will be available locally in September with pricing yet to be announced. For more information visit http://www.sony.com.au