The 50-400mm F/4.5-6.3 Di III VC VXD (Model A067) is the first model in a class of ultra-telephoto zoom lenses designed for mirrorless camera systems with full-frame sensors. Its 8x zoom covers an exceptionally versatile focal length range: from the 50mm standard lens with a relatively wide angle of view and normal depth of field to the 400mm ultra-telephoto, whose narrow field of view allows for significantly enlarged images. Despite the extensive focal length range, this ultra-telephoto zoom lens for Sony E-Mount full-frame cameras is compactly built like a conventional 100-400mm zoom lens. The 50-400mm F/4.5-6.3 is remarkably compact with a length of just 183.4mm and a lightweight of 1,155g, yet it offers unparalleled performance across all focal lengths.

The optical design of the 50-400mm F/4.5-6.3 includes several special glasses that ensure high imaging performance throughout the zoom range. The lens features Tamron's VXD autofocus technology (Voice-coil eXtreme-torque Drive), which is based on a particularly quiet and fast-acting linear motor. The VC image stabilizer (Vibration Compensation), also a Tamron development, helps achieve sharp images in low-light shooting situations. The short minimum focusing distance of the 50-400mm F/4.5-6.3 allows for macro photography at a scale of 1:2 (0.5x magnification). At a focal length of 50mm, the shortest focusing distance is just 25cm.