NIKKOR Lens Glossary

VR

Vibration Reduction (VR)

With NIKKOR's Vibration Reduction system, camera shake information is detected by the VR sensor of the VR lens unit, which is continually in motion inside the lens, aligning the optical axis with your camera's imaging sensor, thereby reducing image blur. By providing the equivalent of shooting at shutter speeds up to 4.5 stops* faster, the system helps you achieve sharper shots when shooting sports scenes, dimly lit landscapes and handheld situations.
* Based on CIPA Standard. The value is achieved when: DX-format lenses are attached to a DX-format digital SLR camera, FX-format compatible lenses are attached to an FX-format digital SLR camera, and zoom lenses are set at the maximum telephoto position.
SWM

Silent Wave Motor

Nikon's original Silent Wave Motor (SWM) converts "traveling waves" into rotational energy to drive the optics used for focusing. The two SWM lens types – ring type and compact type – are specifically chosen to match each lens's specs and design. Any AF-S NIKKOR lens featuring these SWMs delivers extremely smooth, quiet and comfortable auto focusing for both general shooting as well as extreme situations, such as sports and wildlife.
STM

Stepping Motor

An AF-P lens employs an STM (Stepping Motor) for driving the AF. Motor operation is synchronized with pulse electric power, rotating one step per electric pulse. It offers high response and controllability for starting and stopping, and its simple mechanical structure allows for extremely quiet operation. Useful for video shooting and other times when operational noise from the lens is a concern.
[NOTE] The number of compatible cameras is limited. Even for compatible cameras, some models require firmware update.
N

Nano Crystal Coat

Originating from Nikon's work in semiconductor manufacturing technology, NIKKOR's Nano Crystal Coat is an antireflective coating that employs an extra-low refractive index coating featuring ultra-fine, nano-sized* crystal particles. These crystallized particles eliminate reflections inside the lens throughout the spectrum of visible light waves (380 to 780 nm) in ways that far exceed the limits of conventional antireflection coating systems. Nano Crystal Coat not only solves ghost effects caused by red light, which was incredibly difficult for previous systems. It also effectively reduces ghost and flare effects caused by light entering the lens diagonally. The result: clearer images.
*One nanometer equals one millionth of a millimeter.
Fluorine coat

Fluorine coat

Nikon's fluorine coat effectively repels dust, water droplets, grease or dirt, ensuring easy removal even when they adhere to the lens surface. Thanks to Nikon's original technology, it delivers higher durability and is more peel-resistant. Compared to other manufacturers' coating of a similar kind, fluorine coat endures a higher frequency of lens surface wiping and provides longer-duration staying power. Its anti-reflective effect also contributes to the capture of clear images.
SIC

Nikon Super Integrated Coating

Nikon's exclusive multilayer lens coating achieves high transmittance in a wider wavelength range. Even for zoom lenses with a large number of glass elements, this coating system effectively reduces the ghost and flare effects that are likely to occur in backlit situations, helping you achieve high-contrast images with rich gradation. With outstanding color balance and reproduction capability, superb optical performance can be achieved. Ghost and flare effects caused by internal reflections particular to digital cameras are also effectively minimized. This coating system is applied to all current lenses in the NIKKOR lineup.
M/A

M/A (manual-priority auto) mode

Simply by rotating a focus ring, M/A mode allows you to switch from autofocus to manual with virtually no time lag. This makes it possible to seamlessly switch to fine manual focusing while looking through the viewfinder.
A/M

A/M (auto-priority manual) mode

This mode also enables an easy transition from autofocus to manual during AF operation. However, mode switch sensitivity has been altered to reduce the possibility of sudden unintentional switching to manual focus while shooting.
A-M

A-M mode ring/lever/switch

Thanks to a mechanism incorporated in the lens barrel, smooth focusing operation in Manual focus mode is realized in the same way as users have become accustomed to with conventional manual-focus lenses by adding an appropriate torque to the focus ring.
IF

Internal Focusing (IF)

Imagine being able to focus a lens without it changing in size. Nikon's IF technology enables just that. All internal optical movement is limited to the interior of the non-extending lens barrel. This allows for a more compact, lightweight construction as well as a closer focusing distance. In addition, a smaller and lighter focusing lens group is employed to ensure faster focusing. The IF system is featured in most NIKKOR telephoto and selected NIKKOR zoom lenses.
RF

Rear Focusing (RF)

With Nikon's Rear Focusing (RF) system, all the lens elements are divided into specific lens groups, with only the rear lens group moving for focusing. This makes autofocusing operation smoother and faster.
CRC

Close-Range Correction system

The Close-Range Correction (CRC) system is one of Nikon's most important focusing innovations, for it provides superior picture quality at close focusing distances and increases the focusing range. With CRC, the lens elements are configured in a "floating element" design wherein each lens group moves independently to achieve focusing. This ensures superior lens performance even when shooting at close distances. The CRC system is used in fisheye, wideangle, Micro, and selected medium telephoto NIKKOR lenses.
ASED

Aspherical ED glass

Using ED (Extra-low Dispersion) glass that successfully minimizes color fringing as a material, this type of lens features non-spherical surfaces on one or both sides of the glass. It provides superior rendering capability by maximizing the advantages of both ED glass and an aspherical lens – effectively correcting various lens aberrations such as lateral chromatic aberration, coma flare at the periphery, as well as distortion and spherical aberration. It achieves aberration correction of ED glass and aspherical lens in one element, contributing to lens compactness. Adopted in the AF-S NIKKOR 24-70mm f/2.8E ED VR.
ED

ED glass

Nikon was the world's first camera maker to develop ED (Extra-low Dispersion) glass that could minimize prism-caused color dispersion. This low-dispersion ED glass also offers anomalous dispersion characteristics like calcium fluoride crystals, which consequently minimize the secondary spectrum. For lenses using normal optical glass, the longer the focal length, the more difficult it is to correct the chromatic aberration that causes color fringing. Nikon's ED glass, which effectively compensates for this kind of chromatic aberration, is employed in a wide range of NIKKOR telephoto lenses for superior reproduction.
SUPER ED

Super ED glass

Nikon has also developed Super ED glass featuring even lower dispersion properties and extremely high performance in reducing the secondary spectrum, to minimize chromatic aberration even further, as well as other lens aberrations. Adopted in the AF-S NIKKOR 80-400mm f/4.5-5.6G ED VR and AF-S NIKKOR 200mm f/2G ED VR II.
AS

Aspherical lens

This type of lens utilizes non-spherical surfaces on either one or both sides of the glass in order to eliminate certain types of lens aberration. These aspherical elements are particularly useful for correcting the distortion in wide-angle lenses. Such distortions are caused by variations in the magnification of the image, depending on its distance from the optical axis. Aspherical lens elements correct these distortions by continuously changing the refractive index from the center of the lens.
Since the 1960s, Nikon engineers have established design theories and lens-processing techniques to refine the aspherical lens. In 1968, the OP Fisheye-Nikkor 10mm f/5.6 became the first interchangeable SLR lens incorporating aspherical lens elements. Since then, aspherical lenses have been an important part of the NIKKOR lens family, with every new addition to the lineup providing a new level of contrast, resolution and compact design.
Hybrid aspherical lenses: made of a special plastic molded onto optical glass.
Molded glass aspherical lenses: manufactured by directly pressing optical glass into a high-precision aspherical mold.
HRI

High Refractive Index lens

With a refractive index of more than 2.0, one HRI lens can offer effects equivalent to those obtained with several normal glass elements and can compensate for both field curvature and spherical aberrations. Therefore, HRI lenses achieve great optical performance in an even more compact body.
FL

Fluorite lens

Fluorite is a monocrystal optical material that features a high transmission rate within both the infrared and ultraviolet zones.
With its superb anomalous dispersion properties, fluorite intensely blocks the secondary spectrum in order to effectively correct chromatic aberration within the visible light spectrum – something that is more difficult to achieve at longer focal lengths. It is also significantly lighter than optical glass, giving you a more effective lens with less weight.
PF

PF (Phase Fresnel) lens

The PF (Phase Fresnel) lens, developed by Nikon, effectively compensates chromatic aberration utilizing the photo diffraction phenomenon*. It provides superior chromatic aberration compensation performance when combined with a normal glass lens. Compared to many general camera lenses that employ an optical system using the photorefractive phenomenon, a remarkably compact and lightweight body can be attained with less number of lens elements.
* Diffraction phenomenon: Light has characteristics as a waveform. When a waveform faces an obstacle, it attempts to go around and behind it, and this characteristic is referred to as diffraction. Diffraction causes chromatic dispersion in the reverse order of refraction.
D

Distance information

The D stands for Distance. Subject-to-camera distance information is obtained with an internal encoder, which is linked to the lens focus ring. This information is then transmitted to the camera body for high-precision exposure control found in 3D Color Matrix Metering II/III and i-TTL Balanced Fill-Flash. Every AF, AF-S, AF-P, PC and PC-E series lens has a distance signal built in.
G

G-type NIKKOR

For this type of lens, apertures are always selected from the camera body, as there is no aperture ring on the lens itself. Through the powerful control of diaphragm blades, stable high-speed continuous shooting is enabled, even at smaller apertures*.
*Some limitations apply.
E

E-type NIKKOR

An electromagnetic diaphragm mechanism is incorporated inside the body of these lenses and controlled via electronic signals from the camera body. This gives you incredibly accurate aperture control, even when a teleconverter is being used with a super-telephoto lens*.
*Some limitations apply.
DC

AF DC-NIKKOR lenses

AF DC-NIKKOR lenses feature exclusive Nikon Defocus-image Control technology. This allows photographers to control the degree of spherical aberration in the foreground or background by rotating the lens' DC ring. This will create a rounded out-of-focus blur that is ideal for portrait photography. No other lenses in the world offer this special technique.
ML

Meniscus Protective Glass

NIKKOR's exclusive protective glass for lenses comes attached to the front of fast super-telephoto lenses. Normal flat protective glass lets incoming light reflect off the surface of the image sensor or film, especially under a strong light source such as a spotlight. This then reflects again off the protective glass, resulting in a ghost effect. NIKKOR's curved meniscus glass dramatically reduces this re-reflected light, realizing clearer images with less ghosting.
RD

Rounded Diaphragm

When shooting with an ordinary diaphragm, blurry, polygon-shaped spots are likely to appear in images of scenes that include point light sources such as street lamps or holiday lighting at night. A rounded diaphragm is achieved by using specialized blades for a beautiful and naturally round shape for out-of-focus objects.

MTF Chart

MTF (Modulation Transfer Function) is one of the measurements that evaluate a lens' performance; it shows contrast reproducibility of the lens using characteristic spatial frequencies. Spatial frequencies indicate the number of lines per mm.
In the MTF chart of this website, the horizontal axis is in millimeters and shows the distance from the center of the image toward the edges, and contrast value (highest value is 1) is shown in the vertical axis, with fixed spatial frequencies of 10 lines/mm and 30 lines/mm.
The MTF chart for each lens is based on the value at the maximum aperture of the lens; the red line shows the spatial frequency of 10 lines/mm and the blue line, 30 lines/mm.
In the off-axis field, contrast reproducibility of the lens for sagittal direction and meridional direction varies with astigmatic affection. The path of 10 lines/mm indicates the contrast reproducibility of the lens (the higher and straighter is better). The higher and straighter the 30 lines/mm-path is, the higher the resolution of the lens.
Note that the lens performance can not be measured only with MTF chart. Softening or blurring of color also governs measurement.