Sony FE 100-400mm f/4.5-5.6 GM OSS

Andy Westlake tests an impressive lens that’s perfectly matched to Sony’s high-speed Alpha 9

- Andy Westlake

A couple of months ago, I got my hands on one of the first samples of the Sony Alpha 9 to arrive in the UK. This full-frame mirrorless wonder can shoot at fully 20 frames per second using a silent, low-distortion electronic shutter, and even more impressively, adjust autofocus and exposure between each frame. The A9 is surely a sign of where camera design will end up in the future, but one thing was missing – the ability to couple it with the kind of native FE-mount long telephoto lens that sports and action shooters are likely to use.

Now the first such lens has arrived, in the shape of the FE 100-400mm f/4.5-5.6 GM OSS, which Sony also likes to give the decidedly opaque label SEL100400GM. This relatively compact, lightweight optic is a member of Sony’s G Master family, which represents the company’s top-level optical designs. But, at £2,500, it doesn’t come cheap (Canon and Nikon’s equivalents are closer to £2,000). To find out more about it, I put the lens to the test shooting fast jets at the Royal International Air Tattoo at Fairford, Gloucestershire.

Features The FE 100-400mm GM is designed as a high-end telezoom, and it has all the features we’d expect from a lens of this type. The optical formula comprises 22 elements in 16 groups, with two extra-low dispersion (ED) glass elements and one super-ED element employed to keep chromatic aberrations to a minimum. Nano AR coating suppresses internal reflections to minimise flare and ghosting, while a fluorine coating on the front element repels grease and water. For close-up shooting, the lens has a minimum focus distance of 0.98m, giving a maximum magnification of 0.35x, which counts as best in class by a whisker.