Geektech found this Sony’s new prototype lens mounted to a tripod at a trade show, 500mm f/4 G SSM isn’t just any lens and its  optic is impressive enough to warrant some hands-on attention. This  new A-mount telephoto mounted on an Alpha A77 at Sony’s booth at CP+ 2012s. The lens focuses surprisingly quick , especially given its massive 500mm fixed focal length.

The autofocus was impressively fast when mounted to an A77, and the lens should make an even better partner for the full-frame A900 successor that Sony confirmed today. Moving from subject to subject at varying distances, we were typically able to achieve focus in a fraction of a second. The SAL500F40G, as it’s to be known, will be hand built to order beginning in March. It’s as huge as the $16,000+ hole it’ll make in your bank balance, and even in the unfinished form shown off at CP+ looks to be quite the performer.