Nikon AF Lens Designation

Nikon AF Lens Designation

Nikon has produced many different types of AF (autofocus) lenses over the years, many retain compatibility with current cameras. Nikon use a range of designations to identify the features and functions available with each lens. Nikon AF lenses can be split into five basic designation categories AF, AF-D, AF-G, AF-S and DX.

AF
These were the first generation of Nikon AF lenses. All Nikon autofocus SLR cameras are compatible with Nikon AF lenses which contain a CPU (central processing unit). These lenses are easy to recognise as the letters 'AF' can be is identified on the lens and they have CPU contacts on the rear of the lens as shown in the image below.

Early Nikon camera bodies which employ AF technology support basic autofocus but later cameras manufactured since 1996 with advanced metering systems require D (distance) information for exposure metering (see AF-D below). Cameras that support advanced 3D Matrix Metering require distance information to be transmitted from the lens, if a standard AF lens is used, an abridged version of the metering system will be employed.

AF-D
Nikon introduced AF-D series lenses in 1996, while these lenses look similar to AF lenses they contained an encoding microchip that transmits focusing distance information to the camera body, this information is used to enhance the accuracy of the cameras exposure and flash metering systems. Cameras with advanced 3D matrix metering systems require AF-D compatible lenses to take full advantage of this technology. All current Nikon autofocus lenses transmit distance information to compatible cameras and are therefore AF-D compatible, AF-D lenses are recognised by the D designation marked on the lens as illustrated in the image below.

AF-G
AF-G lenses where introduced in 2000, these lenses are similar to AF-D lenses and offer the same functionality as AF-D lenses but do not feature an aperture ring. (an aperture ring is only required by older Nikon SLR cameras which can't detect this information from the lens). For more information on AF-G lenses Click Here.

AF-S (AF-I)
Nikon AF-S lenses and it's predecessor AF-I offer the same functionality as AF-D or AF-G lenses. The difference between these lenses is that AF-S / AF-I lenses contain a focusing motor built into the lens, rather than using the auto focus motor built into the camera body. This system enables faster focusing and in the case of the AF-S lenses near silent auto focusing.

DX
Nikon announced the introduction of DX lenses in 2002 incorporating technology from earlier lens types but offering better performance for Digital SLR users. DX lenses produce a small image circle which does not cover the 135 film area, therefore they are not recommended for use with film SLR cameras as cropping may occur. Their advanced design enables high quality optics and extended zoom ranges to be incorporated into compact lenses designs, for more information on DX lenses </>Click Here.

For details on other designations used by Nikon and the technology behind them; for example IF, ED and VR, please Click Here .