Pre-AI or Non-AI or NAI
The original F-mount, which offers light meter coupling by means of a prong fixed to the aperture ring.
Not an official Nikkor designation, but in common use. Light meter coupling was manual; the maximum aperture of the lens was communicated to the light meter by mounting the lens with the aperture ring set to f/5.6, and then turning the ring to first the minimum and then the maximum apertures.
U, B, T, Q, P, H, S, O, N, D
Appears immediately before or after the Nikkor name on early lenses, designating the number of elements in the design.
Short for Uns (1), Bini (2), Tres (3), Quatour (4), Pente (5), Hex (6), Septem (7), Octo (8), Novem (9), or Decem (10).
An early Nikkor designation for a coated lens. This designation was retired once lens coatings became the norm.
Manual focus with automatic "Aperture Indexing" light meter coupling. The lens has a tab on the aperture ring that allows the camera to sense the current aperture.
An unofficial designation for lenses converted from non-AI to AI. This is accomplished by replacing the aperture ring (using a kit procured from Nikon, now long-discontinued) or by milling and making other changes the original part. Some independent camera repair technicians continue to offer such conversions. Warning: Mounting non-AI lenses which have not been AI'd can damage most modern Nikon camera bodies.
Manual focus with automatic aperture indexing. The successor to AI, AI-S added a notch to the lens mount which mechanically communicated the lens focal length to the camera. This function was only used by the FA, F4, and F501 (N2020) cameras, to tell their program modes to adjust shutter speed based on whether the lens mounted is shorter or longer than 135mm. Generally used to refer to manual focus lenses, however all Nikon autofocus lenses with aperture rings are also AI-S.
AI with Program. CPU-enabled variation of AI-S.
CPU-enabled manual-focus lens with AI-S coupling. Owing to their specialized nature, few lenses of this type have been released.
E or Series E
A lower-cost series of amateur manual-focus lenses, branded "Nikon" but not "Nikkor."
The original autofocus designation, indicating focus driven mechanically from a motor inside the camera body.
Autofocus-Silent. Uses a "Silent Wave Motor" (ultrasonic motor) to focus quietly and quickly. Similar to Canon's USM technology. Introduced in 1996.
Autofocus-Internal. Driven by a coreless DC motor. Used only in long telephoto lenses (300 mm f/2.8 through 600 mm f/4.0) starting in 1992. Replaced with AF-S in 1996.
Extra-low Dispersion glass. Reduces chromatic aberration. Recently, "Super ED" glass has been introduced as well.
Internal Focus. Focusing is accomplished through the movement of internal lens groups, eliminating extension and rotation of the front lens element.
Lens designed for Nikon DX format sensors. The image circle matches the smaller sensor area of Nikon's digital SLRs. A vignetted image may be produced if used on a 135 format camera, although some DX lenses cover the full 135 frame at longer focal lengths.
Vibration Reduction. Uses a moving optical group to reduce the photographic effects of camera shake. Some VR lenses also support a panning mode, detecting horizontal movement of the lens and minimizing only vertical vibration. Similar to Canon's Image Stabilizer, Sigma's OS, etc. The latest VR type, implemented in the 18-200 mm f/3.5-5.6G ED-IF AF-S VR DX and 105 mm f/2.8G ED-IF AF-S VR N Micro-Nikkor, is called "VR-II," but is not currently official Nikkor nomenclature.
Distance/Dimension. Indicated after the f-number number. It means the lens is capable of using Nikon's 3D Matrix Metering on bodies that support it. The lens transmits focus distance information, which is incorporated into the camera's exposure calculations.
Indicated after the f-number. G lenses do not have an aperture ring, and the aperture can only be controlled electronically by the camera body. Only autofocus bodies with command dials are capable of controlling G lenses. Older autofocus bodies will work with G lenses in shutter priority and program modes. G lenses otherwise have the same characteristics as D lenses.
Guide Number. Aides in making flash exposures on cameras without automatic flash metering. The flash's guide number is set on the lens, and the aperture is accordingly coupled to the lens's focus ring for correct exposure.
Micro lenses are capable of high reproduction ratios for macro photography.
Indicates the Nano Crystal Coat, a new type of lens coating that originated in Nikon's semiconductor division. The coating is currently used in the 300 mm f/2.8G ED-IF AF-S VR and 105 mm f/2.8G ED-IF AF-S VR Micro Nikkor. Lenses with this coating feature the logo of an "N" inside an elongated hexagon on the name plate. ("N" is also used, unrelatedly, as a non-official designation for the "New" version of a lens. For example, the change from the plastic focus rings on early AF lenses to rubber focus rings like AI and AI-S lenses is often given this designation.)
Perspective Control. Lens includes movements to control perspective and depth-of-field. These include the shift-only 28 mm and 35 mm PC Nikkors, and the tilt/shift 85 mm f/2.8D PC Micro Nikkor.
DC - Defocus Control. DC lenses have a separate control ring for spherical aberration, which affects primarily the appearance of out-of-focus areas, also known as bokeh. At extreme settings, DC lenses can generate an overall soft-focus effect.
IX - Lenses designed for use with the now-defunct Pronea APS SLR. These are all autofocus zoom lenses. They are not compatible with cameras outside of the Pronea system