All current Nikon lenses incorporate AF-D technology.
Nikon manufactures one of the most complete lines of camera lenses of any camera manufacturer. The various letter designations found on Nikon lenses indicate different mechanical and optical properties of the lens. Designations such as AF-D, AF-S and AF-I all indicate different mechanical changes made to Nikon's autofocus lens line.
Original AF Lenses
Even though all Nikon SLR/DSLR lenses use the original Nikon "F" bayonet mount, not all Nikon lenses function fully on all Nikon cameras. In 1986, when Nikon first introduced its autofocus lenses, it gave them the designation of AF. The original Nikon AF lenses used a slotted coupling on the lens to connect with the camera body. The slotted coupling allowed a flat prong in the camera body to fit into the slot. The flat prong literally made the lens' focusing mechanism turn, giving the lens autofocus capabilities.
AF-D Designation
Nikon introduced AF-D lenses in 1992. The AF-D designation on Nikon lenses means the autofocus lens now has the ability to read and translate distance information to the camera. This improvement in Nikon's lens technology allows flash units to obtain more accurate camera-to-subject distance information. In other words, prior to AF-D lenses the camera's metering system was handicapped because the camera never knew the exact distance of the subject from the camera. With AF-D lenses the camera had precise distance information. This resulted in more accurate exposures especially when used with a dedicated Nikon flash unit. The first two Nikon lenses to incorporate the AF-D designation were the 35-70mm f/2.8D AF and the 80-200mm f/2.8D AF.
Current Technology
Today all Nikon lenses incorporate distance information in their design. Nikon no longer marks lenses as AF-D, but still uses the technology. As of 2011 Nikon's latest mechanical and optical technology includes increased vibration reduction with its VR lenses, nano crystal coating for better anti-reflection capabilities and electronic diaphragm control for its PC (perspective control) lenses. Traditionally the aperture control on PC lenses required manual control. Nikon's latest PC lenses have full automatic aperture control on certain higher-end Nikon cameras.
Other Autofocus Designations
Other Nikon lens designations for its autofocus camera line include the AF-I designation. AF-I lenses incorporated a coreless motor integrated into the lens. This was primarily used on Nikon's longer telephoto lenses such as the 300mm f/2.8 and the 600mm f/4.0. AF-S lenses featured a silent wave ultrasonic motor designed into the lens. The ultrasonic motor allowed faster autofocus capabilities. The first of Nikon's lenses to use the AF-S designation were the 300mm f/2.8, 500mm f/4.0 and 600mm f/4.0.
Tags: Nikon lenses, distance information, AF-D lenses, lenses camera, lenses incorporate
