Nikon Lenses – An Explanation of Terms

If you’re new to Nikon lenses, or perhaps even if you’re not, the endless strings of seemingly random letters that Nikon attaches to the end of their lens names can seem confusing. Beyond the basic focal length and aperture designations, there’s a lot you can learn from it.

Nikon lens naming system can sometimes be rather confusing, because Nikon uses letters and abbreviations to identify different lens components. Knowing what each of those stands for can be valuable, especially during the process of evaluating and purchasing lenses. Since Nikon has been producing lenses for so many years and the technology has significantly changed overtime, some of the older abbreviations are no longer used on modern lenses and those are marked appropriately below.

Most new lenses are autofocus, which Nikon thankfully designates as AF. That’s an easy one, but when it comes to non-autofocus lenses it rapidly gets more complicated. The earliest manual focus lenses didn’t need extra letters to designate them as such since no other kinds yet existed. Today however they are known as non-AI or pre-AI to distinguish them from the later AI lenses. If you have a lens with a funny metal forked prong (known commonly as “ears”) sticking out from one side near the bayonet mount, it may well be a non-AI lens. These ears actually mated with a prong on early camera bodies. To tell for sure if it is non-AI, check the outer black rim around the lens mount. If it’s continuous and smooth all the way around, you have a non-AI lens. Today, purchasing non-AI lenses is pretty much limited to lens collectors rather than photographers. In fact, such lenses aren’t even compatible with current bodies and can in fact cause damage if used.

The designation AI stands for auto-indexing. These lenses still have ears for backward compatibility but now have an AI ridge on the edge of the lens mount as described above. This made changing lenses far simpler since the camera and lens mated correctly pretty much on their own. AIS lenses are similar but have a scoop shaped groove machined into the bottom of the lens mount to improve the process. Nikon used to offer a service to modify a non-AI lens to add an AI ridge (referred to as being “AI’d”). There are still a few companies out there who can do this if you are in need – Google is your friend.

Around about 1986 Nikon introduced AF lenses that featured a CPU chip built into the lens. Computer components are commonplace today, but this was indeed radical back then. Still, other companies were coming out with AF lenses too so Nikon had to compete. In addition to the mechanical couplings that earlier lenses had, AF lenses included a row of small metal bumps that served as electrical contacts on one side of the lens mount rim. Over the years Nikon has added additional electrical signals and it is quite common for new lenses to have more contacts than are utilized by current bodies so Nikon can build a path to the future.

Early AF lenses were designated simply as AF but Nikon later came out with AF-D to pass a distance signal based on how the lens was focused. AF-D was mainly just hype, the signal consisted mainly of just “near” or “far.” It wasn’t an actual distance measurement in feet or meters or anything. Some macro situations did benefit from the added information though, primarily in terms of flash coverage.

Then came AF-S which offered a huge advantage in that the lens contained a motor to focus much more quickly than earlier AF systems that made use of a mechanical linkage to a focusing motor in the body. The “S” stands for “silent wave” and compared to the earlier gear linage system, it was amazing. Quite a few lenses these days are AF-S but when they came out they were revolutionary. Being able to focus that quickly was cool indeed.

There were and still are a few AI-P lenses that weren’t auto-focus but still had CPUs in them. I currently own the 24 and 45mm macro tilt-shift AI-P. Having a CPU allows them to be compatible with all current Nikon bodies even if you do have to focus them yourself. Don’t be confused by the letter “P” in the names of some non-AI lenses which stood for five (“penta”). For a number of years Nikon labeled lenses based on how many elements they contained. “Q” stood for “quadra” (4), “H” for “hexa” (6) and so on. If you are unsure, look for the row of metal bumps on the rim of the mount.

These are the main types of lenses Nikon has produced thus far. Additionally, there are quite a few letters that have been used to describe various features. Here are some of the main ones:

Nikon Lens Naming Explained

Here is a detailed list of all Nikon lens abbreviations:

• AF – stands for Auto Focus, which means that the lens can automatically focus through the camera.
• AF-D – Auto Focus with Distance information. Same as AF, except it can report the distance between the subject and the lens and then reports that information to the camera. The distance information can be useful for metering. See “D” acronym below. No longer used on modern lenses.
• AF-I – Auto Focus with an integrated focus motor. No longer used on modern lenses.
• AI-P – Manual focus AI lenses with a built-in CPU that transfer data to camera for exposure metering. No longer used on modern lenses.
• AF-S – Auto Focus with Silent Wave Motor. The AF-S lenses have built-in motors inside the lens, which work great on all cameras without built-in motor such as Nikon D40/D40x, D60, D3x00 and D5x00 series.
• AI – Indicates “Automatic Indexing”. This abbreviation was used on very old manual focus lenses, so it is no longer used on modern lenses.
• AI-P – Manual focus AI lenses with a chip to send data to the camera. No longer used on modern lenses
• AI-S – Manual focus lenses that could be used with cameras that had Program and Shutter Priority camera modes. On AI-S lenses, aperture can be changed directly from the camera. No longer used on modern lenses.
• ASP – Lens contains at least one aspherical lens element, which is used for correcting coma and other lens aberrations. Sometimes goes by “AS”.
• CRC – Close Range Correction lenses that are optimized for close focusing distances.
• D – D-type lenses send camera to subject distance information to the camera.
• DC – Defocus Control lenses allow controlling the bokeh, which is great for portraits.
• ED – Extra-low Dispersion glass elements within the lens do not disperse the light as it enters the lens. Most modern top of the line Nikon lenses contain ED glass, which also delivers better sharpness and reduces chromatic aberration or color fringing in photographs.
• E – The new “E” type lenses feature electronic diaphragm control, similar to what we have previously seen on PC-E lenses (below). These lenses do not have the aperture lever on the back of the lens and are fully electronic, so there is no way to manually adjust the aperture anymore. “E” type lenses are more accurate than “G” type lenses, especially for shooting at high frame rates, because the lens can stop down to a desired aperture without the need to be engaged from the camera motor.
• FL – Newly introduced in 2013. Indicates that the lens has Fluorite Lens elements, which are optically superior and significantly lighter glass elements. A number of new lenses such as the Nikon 800mm f/5.6E FL ED VR, Nikon 600mm f/4E FL ED VR etc now feature fluorite elements.
• G – If you see a letter “G” after aperture in the lens, for example “Nikon 50mm AF-S f/1.4G”, it means that the lens does not have an aperture ring like the old lenses. All modern Nikon lenses are “G”, because the aperture ring is only needed for old manual focus camera bodies.
• IF – Internal Focusing allows the lens to quickly focus by moving some of the elements inside the lens barrel, without moving the front barrel or extending in size. Many of the modern Nikon lenses such as Nikon 18-200mm f/3.5-5.6G VR II and Nikon 70-200mm f/2.8G VR II are IF lenses. Lenses with IF acquire focus faster than lenses without IF.
• Micro – Same thing as Macro, which is designated for macro lenses for close-up work.
• N – The letter “N” stands for Nano Crystal Coat and it is always displayed in a golden sticker on all top of the line Nikon lenses. Nano crystal coating, a high-tech coating used on some newer lenses to cut down on ghosting and flare. This can make a big difference on some lenses when shooting outdoors. Like P, N is also another one of those letters Nikon used in the early days for how many elements a lens had. Back then N stood for “nona” or 9 elements. Times change though, and letters get reused. It is a special type of glass coating that
• NOCT — Nocturnal. These lenses feature extremely wide maximum aperture and are designed for shooting in very low light.
• PC-E – Perspective Control with electronic diaphragm. Allows lenses to tilt and shift to create special effects.
• RF – Rear Focusing. The focusing is done by moving the rear element inside of the lens, which means the rear element moves while focusing. The latest Nikon 24mm f/1.4 lens, for example, is RF.
• Reflex-Nikkor – Refers to the mirror lens system Nikon used for example: Reflex-Nikkor 2000mm f/11.
• SIC – Lenses with Super Integrated Coating have better color performance and are generally deal better with ghosting and flare.
• SWM – Silent Wave Motor allows quiet autofocus with a quick switching between autofocus and manual operation. Overriding autofocus is very simple – you just turn the focus ring, instead of switching to manual mode first like you have to on AF-D lenses.
• VR – Vibration Reduction allows using lenses hand-held without the need for a tripod in low-light situations. Special motion sensors inside the lens detect hand motion and compensate for the motion by stabilizing the lens in the opposite direction.
• CX – Nikon has a mirrorless system called “Nikon 1”, with a sensor smaller than DX. Although the CX abbreviation is not included in the lens title, you might see it in descriptions and other marketing material. If a lens title starts with “1 NIKKOR”, it means that the lens is specifically designed for CX camera bodies such as Nikon 1 V1/V2/J1/J2. CX lenses do not work on any other Nikon mounts.
• DX – If a lens says “DX”, it means that it is specifically designed for APS-C DX camera bodies (see sensor size comparison below) such as Nikon D3000/D5000/D90/D300s. DX lenses do work on FX bodies (they will physically mount), but will operate at only half the resolution.
• FX – this abbreviation indicates “full-frame”, as in 35mm film equivalent. Abbreviations like FX, DX and CX indicate format size (size of the digital sensor). You will never see FX on descriptions of lenses, because unless indicated otherwise, all lenses are full-frame by default (see DX and CX below).
• IX – Physically about the same size as the DX digital format, there once was a film system known as APS or “Advanced Photographic System.” Far from being advanced today, the system is completely obsolete. IX was Nikon’s name for its APS lens line. Nikon also made lenses with the type of IX. These lenses were designed for the Pronea series of cameras, which used the Advanced Photo System format film. They cannot be used on 35mm film or digital bodies, so just ignore them unless you have a Nikon Pronea.

Example

Let’s take a look at the following Nikon lens:

Nikon AF-S NIKKOR 105mm f/1.4E ED Lens

As you can see from the lens image, it says “AF-S Nikkor 105mm 1:1.4E ED” on the lens, which basically means that it is a fixed Nikon (Nikkor and Nikon are the same thing) 105mm lens with a maximum aperture of 1.4, has built-in auto focus with silent wave motor (AF-S), has an electronic diaphragm control (E) and contains extra-low dispersion glass (ED). The large letter “N” on the side indicates that the lens has Nano Crystal Coat. The Nano Crystal Coat provides an extremely high preventive effect against reflections over a wide wavelength range by reducing the reflection of light.

Finally, even Nikon lens hoods have meaningful acronyms; the letters in the name of the hood specifies something about the hood itself:

• • HB – Bayonet mount hood
  • HE – Extension hood for long lenses that already have a hood
  • HK – Slips onto the lens and then locks using a knob
  • HN – Screw mount hood
  • HR – Rubber hood, usually screw mount
  • HS – Snaps onto lens like a lens cap

Lens hoods can either be metal, plastic or carbon fibre.

If you need to determine what other third party vendor’s names are for the same Nikon lens attributes, here are the primary things you need to know:

	Nikon	Sigma	Tamron	Tokina
Lens with motors	AF-S or AF-I	HSM	USD	IF-S
Lens with stabilization	VR or VR II	OS	VC	not applicable
Lens for Full Frame Cameras	(FX)	DG	Di	(FX)
Lens for Cropped Frame Cameras	DX	DC	Di II	DX

I hope this sheds some light on the subject and helps you make an informative decision on your next Nikon lens, whether you buy locally new or second hand on eBay or Amazon.

Acknowledgements

Information sourced from various websites and adapted for this blog, including:

http://www.earthboundlight.com/phototips/nikon-lens-letter-codes.html
https://support.nikonusa.com/app/answers/detail/a_id/9919/~/glossary-of-nikkor-lens-terms
https://photographylife.com/