Some selective Nikon terminology, abbreviations and acronyms .....

I am Nikon
The rather simple, but extremely clever 'I AM NIKON' logo is now world famous and is regularly used and adapted by Nikon for their ongoing advertising purposes; recent examples being 'I AM RESPONSIVE' and 'I AM HIGH RESOLUTION’ or, in respect of promoting the new D500, 'I AM CONDENSED POWER' and for the flagship D5, 'I AM VISION OUTPERFORMED'.

It's a very smart marketing tool, so I thought I'd use it here in the context of ‘I AM CONFUSED’ in reference to the many different abbreviations that both the Nikon and Nikkor lens brands have used over the years to describe their equipment. It certainly can be confusing, so I thought it would be useful to include this page to explain what some of the more common ones actually mean.

Cameras :

FX : Nikon’s term for a full-frame camera incorporating a 36x24mm image sensor - the equivalent of 35mm format.

DX : Nikon’s alternative term for the APS-C crop-frame image sensor format, being approximately 24x16mm. The third smaller diagonal size of the DX format gives an effective 1.5x focal length multiplier compared with the same lens on an FX camera thereby producing a tighter crop without the need to increase the focal length - a benefit that’s advantageous for telephoto and macro photography.

CCD & CMOS : these are types of image sensor, with CCD (charged-coupled device semiconductor) being the older technology and CMOS (complementary metal–oxide–semiconductor) being the current technology used since the launch of the D300 and D3.

Teleconverters :

TC : the abbreviation for a teleconverter, which is effectively a secondary lens that’s mounted between the camera and the photographic lens in order to enlarge the image size. Excluding the special 1.25E model that’s only used solely with the 800mm f/5.6 lens, Nikon’s current teleconverters are the TC-14E III, TC-17E II and TC-20E III giving effective enlargement of 1.4x, 1.7x and 2.0x respectively. Teleconverters reduce the amount of light reaching the sensor with the 1.4x losing one-stop, such that a f/2.8 lens would become a f/4, or a f/4 becoming a f/5.6. Similarly, the 1.7x loses one-and-a-half stops, and the 2.0x two-stops. I’ve made some notes about using teleconverters within part 2 of my section on ‘cameras and lenses’.

Lenses :

D : the designation, standing for ‘distance’, that was used on older lenses, such as the 300mm f/4D, that included a manual aperture ring.

G : whilst I cannot find out what the ‘G' actually stands for, it’s the designation used on virtually all modern lenses that do not incorporate an aperture ring, as this was only necessary on older manual focus lenses. As with the previously noted ‘D' designation the ‘G' is always written directly after the lens aperture (ie. f/4G).

E : this new lens type designation stands for ‘electronic’ or, more precisely, lenses that feature an 'electronic diaphragm mechanism’ within the lens barrel. This mechanism provides highly accurate electronic diaphragm or aperture blade control especially when using normal auto-exposure during high frame rate continuous shooting (with conventional ‘D’ and ‘G’ lenses the diaphragm blades are operated by mechanical linkage levers).

FL : indicates that the lens incorporates ‘Fluorite' elements, which are optically superior and significantly lighter than normal glass elements - first seen in 2013 and now being used on certain new lenses such as the 500mm f/4E FL VR.

ED : stands for ‘extra-low dispersion’ glass, which is used in most high-end Nikon telephoto lenses in conjunction with normal optical glass to obtain optimum correction of chromatic aberrations.

IF : this is an acronym for ‘internal focusing’, being a term that defines a lens where only the internal lens group shifts during focusing. These lenses do not extend during operation, which makes them more compact and capable of closer focusing distances. My 70-200mm zoom is an IF lens and doesn’t extend, whereas my 24-120mm and 200-500mm are not and, therefore, do extend when being zoomed out. The IF designation is usually appended after ED and separated with a hyphen (ie. ED-IF) and follows the aperture and lens type

AF-S : this hyphenated abbreviation is used for lenses that incorporate 'auto-focus' with Nikon’s integrated 'silent wave motor’, which has it’s own acronym of SWM. This advancement in AF lens technology uses ultrasonic vibrations, rather than a gear system, to focus the lens, providing smooth, silent and precise auto-focusing. Mid to high range camera bodies include their own built-in motor, but lower end models such as the older D40 and D60 or the newer D3XXX or D5XXX series cameras do not and, therefore, are reliant on this technology.

VR : the acronym for Nikon’s in-lens 'vibration reduction’ system, which is an image stabilization technology that helps minimise blur caused by camera shake. Used correctly the system claims to provide the facility of shooting at a shutter speed three stops faster, or with the newer second generation VRII of up to four stops faster. VR can be turned on or off, and subject to the lens may have additional control positions for ‘normal' or ‘active' use with the latter being used when photographing from a moving vehicle or boat for example. Some lenses may also incorporate a ‘tripod’ or ‘sport’ mode position. In all cases the lens manual will explain which setting is best for a given situation or use.

Bringing the above together …..

The above definitions are those that are normally used within the full Nikkor lens model description,
for example my 70-200mm f/2.8G ED-IF AF-S VRII lens :-
  • has a zoom range extending from 70mm to 200mm,
  • incorporates a fast f/2.8 maximum aperture,
  • is a standard modern lens without an aperture control ring (G),
  • incorporates extra-low dispersion glass (ED),
  • has internal focusing (IF), such that the lens barrel doesn’t extend when being zoomed out,
  • has integrated auto-focus together with a silent wave motor (AF-S),
  • and utilises the latest vibration reduction system (VRII).

The actual lens incorporates a nameplate under the zoom distance indicator window, which is in a similar format to all other Nikon lenses - on this particular lens it reads AF-S NIKKOR 70-200mm 1:2.8G II ED, being an abridged version of the full model description. The only difference here, being that the II denotes that this is the second generation of the lens and not that it has the VRII technology. It’s a common misconception that the II on the lens plate refers to the VR, but it doesn’t as the type of VR is only confirmed within associated Nikon literature, specification sheets or the lens instruction manual.


The plate also includes a large letter ’N’ indicating that the lens has ‘nano crystal coat’, which is an anti-reflective coating that also reduces ghost and flare that conventional lens have trouble removing.

Additional aperture, optical and focus information together with physical characteristics such as size and weight will be found in the full written specification.

The optical information is particularly important if you want to know how the lens glass elements are used and distributed within the lens construction. For example if you read the specification for the new 500mm f/4E FL ED-IF AF-S VR lens you will see that it has a total of 16 elements in 12 groups - 2 are Fluorite (FL) positioned towards the front of the lens, which help reduce and balance the weight as well as being optically superior, 3 are from ‘extra-low dispersion’ glass (ED) with one positioned at mid point and the other two towards the back, and with the remainder being standard optical glass. The optical specification also confirms that the lens incorporates 9 rounded diaphragm blades, which is an important design feature affecting bokeh.

The lens focusing switch …..

The only other abbreviations I’ll explain are those relating to the lens focusing switch. These controls are not always the same but, again using the 70-200mm lens as the example, the three switch control has provision for :-

A/M : the auto-focus priority setting that allows AF to be overridden by manually adjusting the focus ring, but with the focus ring sensitivity setting being lower than in M/A mode thus making it more difficult to unintentionally adjust the focus ring.

M/A : this intermediate setting allows easy overriding of the auto-focus system via the manual focusing ring.

M : switches the lens from auto-focus to full manual focus control.