The NEX-RETRO is a unique adapter for macro photography which allows a Sony E-mount lens to be reversed on a Sony E-mount body, and still retain full lens functions including AF and TTL metering. Reversing a lens on a camera body creates a high quality and high magnification macro lens. For example, at 45mm a reversed 18-105mm lens will give a 2:1 magnification, with more flexibility than a typical macro lens. Even greater magnifications can be achieved when mounted on a bellows. And, because a lens is computed to work best at infinity, reversing it means that it gives superb quality at high magnifications.