What is it? The Fujifilm Fujinon GF50mm is a highly compact and relatively lightweight lens for Fujifilm medium format mirrorless cameras. It’s the equivalent of a 40mm on a full-frame 35mm camera, and at one time, back in the 70s, this focal length was hugely popular. Much of that had to do with price, as they competed with medium-speed (F1.8/2) 50mms – the kit lenses of the day – and were often sold as a more affordable alternative. These smaller and lighter 3-group, 4-element Tessar ‘pancake’ designs were and still are highly compelling. Indeed, the Olympus Zuiko 40mm F2 is around £600, secondhand, and the Contax Zeiss T* 45mm F2.8…