The Ultimate Guide to Nikon Lens Technology
This guide will go through all of Nikon’s F-mount lens lines and naming conventions, for everyone who’s ever wondered what all the different letters on a lens means or what the difference between different lines are.
This is the latest line of Nikon lenses. The E stands for Electronic, since the lens uses an electronic contact with the camera to stop down the aperture, rather than a physical aperture lever. The first Nikon E lenses were the PC-E lenses - perspective control, or tilt-shift, lenses that can’t use physical aperture levers due to the fact that parts of the lens move around quite a bit. Now, Nikon’s extending the E line to include the 24-70 and 70-200 workhorse zooms, the telephoto prime line, and even some cheaper zooms like the 200-500.
The advantage of the electronic aperture is that it gives less variance in exposures when shooting fast bursts, like 10 fps. Physical aperture levers can’t keep pace as well, so sometimes it’s a little more or a little less stopped down than you want. It’s also one less moving part, so in theory it should be more durable, though that’s up for debate.
However, E lenses will not stop down on older DSLRs (pre 2007), or film cameras. There is a workaround
if you need to stop the lens down on an older camera or for reversing the lens for macro, but it requires a DSLR that works with it. The default position for E lenses is to be wide open when not connected to a camera.
The E is typically listed right after the f-stop in the lens’s name, like AF-S NIKKOR 24-70mm f/2.8E ED VR.
The predecessor to E lenses, G lenses have a physical aperture lever, and when not connected to a camera their resting state is to be fully stopped down. However, unlike D lenses, G lenses do not have an aperture ring. Some very old cameras are unable to change the aperture of G lenses, but all DSLRs should be able to, along with many film cameras.
As far as I can tell, all G lenses are also AF-S lenses, meaning they have a focusing motor built into the lens. (I’ll cover AF-S later in this article.)
The G is typically listed right after the f-stop in the lens’s name, like AF-S NIKKOR 50mm f/1.8G.
The D series of lenses came before the G line. D lenses have an aperture ring, so with older cameras you could control the aperture from the lens. With newer cameras, you’d turn the ring to the smallest aperture (highest number), and the camera would be able to control the aperture just like it does with G lenses.
D lenses usually lacked an autofocus motor, relying on the camera’s focusing motor. However, there were some AF-S D lenses, like the AF-S NIKKOR 28-70mm f/2.8D. Often photographers refer to D lenses without focusing motors as AF-D lenses.
Note that the D stands for Distance, meaning that D lenses provide camera to subject distance information to the camera. G and E lenses do the same, and thus are technically also D lenses. However, when we talk about D lenses we almost always mean the lenses with D in the name.
The D is typically listed right after the f-stop in the lens’s name, like AF Micro-NIKKOR 60mm f/2.8D.
Ai-P lenses are manual focus lenses, but they were the first Nikon lens line to get a CPU chip allowing for more advanced automatic exposure use with cameras. There are only three Ai-P lenses, the popular 500mm f4, the mythical 1200-1700mm f5.6-8, and the weirdly modern 45mm f2.8.
As with other lenses of the era, there is an aperture ring but by setting it to the minimum aperture it can be controlled by the camera.
The P is typically listed right after the f-stop in the lens’s name, like NIKKOR 500mm f/4P IF ED.
Nikon’s S series of lenses were the first to introduce autofocus operation (excluding two lenses that only worked with three cameras, and a teleconverter that offered limited AF capability to manual focus lenses). Like the Ai-S lenses before them, the aperture could be set via the aperture ring or by the camera if set to the minimum aperture.
Unlike many future autofocusing lenses, all S lenses had a distance scale under a clear plastic window, typically located at the end of the lens rather than near the mount like today’s lenses. Most looked somewhat cheap and plasticky, but there weren’t any other true autofocus options for Nikon.
The S is typically listed right after the f-stop in the lens’s name, like AF Zoom NIKKOR 70-210mm f/4S.
Ai-S stands for Auto Indexing Shutter, and Ai-S lenses were the first Nikon lenses that allowed the camera to control the aperture when set to the minimum aperture on the aperture ring. This allowed them to be used in shutter priority mode, hence the term shutter in the name.
Ai-S lenses are manual focus only, but aren’t built quite as well as the earlier Ai lenses, and use aluminum for the silver ring instead of chrome.
The Ai-S is typically before the NIKKOR in the lens’s name, like Ai-S NIKKOR 600mm f/4 IF ED.
Ai, or Auto Indexing, lenses were introduced in 1977, and are the first line of lenses to be compatible with all modern DSLRs (though exposure metering doesn’t work with some lower-end DSLRs). This is why photographers often say the F-mount is from 1977. In reality, the F-mount was introduced in 1959, but lenses from before 1977 will only work on the Nikon Df or cameras of their era without modification. Ai lenses do not offer aperture control from the camera, you must set the aperture ring to the desired f-stop.
Ai lenses have a notch in them which catches a little metal rod on the camera, and from the position of the notch the camera can tell what aperture the lens is set to. Since non-AI lenses don’t have this notch, they could break the metal rod on your camera if you try to mount them, so stick with Ai lenses or newer unless you have a Df which can fold the rod up. Or you can modify older lenses to add that notch and use them with newer cameras.
The Ai is typically before the NIKKOR in the lens’s name, like Ai Zoom-NIKKOR 80-200 f/4.5.
From 1959 to 1977, Nikon made lenses for the F-mount in the F, C and K series. These lenses will not work on modern cameras unless they’re converted to Ai lenses, except for the Nikon Df which can accomodate them.
As such, most photographers don’t use them, and generally the optics don’t hold up that well compared to modern lenses. Often they’re more of collectors items than anything.
Now we’re done with the main lens lines, and into the autofocus types. However, there’s a bit of confusion, since some AF lenses (and AF-N and AF-I lenses) came in between the S series and the D series, and didn’t really have any identifier other than their AF type. Don’t worry about that too much, just keep it in mind so that you don’t assume that a lens is a D lens if it actually isn’t.
AF lenses were Nikon’s first focusing system, and they relied on the focusing motor in the camera to focus. Introduced in 1986, early AF lenses had a small, plastic focusing ring and an aperture lock that’s pushed and twisted to lock.
In 1988 Nikon updated their AF designation to AF-N. The actual performance of the lenses didn’t change, but the focusing ring was now made of rubber and was wider, and the aperture lock was a simpler sliding design.
Introduced in 1992, the same year as D lenses, AF-I lenses have a built in focusing motor. Typically reserved for large, expensive lenses like telephoto primes, AF-I lenses also allowed for manually overriding the AF unlike lenses that relied on the camera’s AF motor. The I stands for Integrated, since these were the first Nikon lenses with an integrated motor.
AF-S lenses are an update to AF-I lenses. They do not rely on the camera’s AF motor, allowing for manual AF override on most (but not all) lenses and also working on lower-end cameras that don’t have AF motors. The S stands for Silent Wave, which is Nikon’s term for the ultrasonic motor they use.
The newest addition to Nikon’s AF technology, AF-P lenses use a stepping motor rather than an ultrasonic motor. Unfortunately, they aren’t compatible with older cameras, be sure to check if they work with your DSLR, and you may need a firmware update.
AF-P lenses tend to be quieter, and faster for the price. So far AF-S is favoured for larger lenses though, as they tend to be more powerful than AF-P motors. They’re ideal for video however, where silent autofocus is key.
ED stands for Extra-low Dispersion, and that refers to the lens elements. If at least one glass element is a special Extra-low Dispersion element, the lens will have ED in the name. This should help improve sharpness and reduce chromatic aberrations, and ED glass is usually found in Nikon’s higher-end lenses.
IF stands for Internal Focusing, meaning that the lens does not extend when focusing. Most higher-end lenses are internally focusing, whereas cheaper lenses change length when focusing.
IF-ED simply means that the lens has both extra-low dispersion glass, and focuses internally.
FL stands for Fluorite, meaning that the lens has fluorite elements in it. Fluorite is lighter than glass, and also optically more refractive allowing for better lens designs. Typically it’s used in the front element of super telephoto lenses, where it allows for big weight savings. Canon’s used fluorite in their telephotos for a while, but Nikon started quite a few years later. Fluorite is potentially more fragile to impacts though, but it shouldn’t be a problem for most people.
Micro means that the lens can take photos with a reproduction ratio of at least 1:2, or more often 1:1. So if you have a 36mmx24mm sensor, you could fill the frame with a 36mmx24mm subject. Other manufacturers tend to use the term macro instead of micro.
N stands for Nano crystal coating, or Nano coating. It’s a coating on the glass that helps to reduce internal reflections, yielding better contrast and potentially sharper images. Most of Nikon’s professional level lenses with gold rings are nano coated.
VR stands for Vibration Reduction. It’s the system in the lens that moves lens elements to compensate for camera shake, allowing you to get sharp shots at slower shutter speeds. Most modern zoom lenses have VR, as well as most modern telephoto primes, but it’s rare in shorter primes as well as in lenses prior to the G series.
Sometimes you’ll see it listed as VR II in the name. VR II isn’t actually a different VR system, it just means that it’s the second lens of that focal length and aperture with VR. However, there are different VR systems, they just aren’t listed in the name. Check the specs to see how many stops the VR is rated for.
PC and PC-E
PC stands for Perspective Control, and it means that the lens can shift to gain a different view without tilting the camera. This allows for you to reduce perspective distortion by keeping the camera level with the subject. Most PC lenses also allow you to tilt the plane of focus, giving you much more control over what’s in focus, similar to technical cameras.
Some older PC lenses had a plunger mechanism to operate the aperture, since mechanical aperture linkages with the camera wouldn’t work. Newer PC-E lenses use an electronic connection however, allowing you to control the aperture from the camera. Interestingly, the 24mm, 45mm, and 85mm PC-E have PC-E in the name, and D after the aperture. The new 19mm lens lists PC, and then E after the aperture. It is the same as PC-E though, so keep that in mind for new PC lenses too - if they list E after the aperture they may be called PC instead of PC-E, despite being the same.
DC stands for Defocus Control, and it’s found on only a couple older lenses. Defocus control gives you more control over whether the background is more out of focus or the foreground is more out of focus, and can be useful for portraiture.
DX means that the lens only covers the DX, or crop sensor, image circle. You can use DX lenses on full frame cameras, but there will be heavy vignetting so you’ll have to crop your photos.
If a lens is not marked with DX in the name, that means it covers the full frame image circle. DX lenses are good for crop sensor cameras since they tend to be smaller, lighter, and cheaper, but if you plan to upgrade to full frame in the near future it may be worth simply buying full frame lenses.
FX, Nikon's term for full frame, is generally only used with cameras. So if a lens doesn't have DX in the name it should work with both FX and DX cameras.
PF stands for Phase Fresnel, and it means that the lens uses special fresnel elements to reduce the size and weight of the lens. Sometimes this can cause weird flaring, but in most cases it’s optically as good as normal glass, while allowing for a dramatically smaller design.
This is rarely, if ever, listed in the name, but you might see it in the specs. CRC stands for Close Range Correction, and it means that the lens employs floating lens elements to ensure that it’s sharp at all focusing distances. This term isn’t used much now though, you’re much more likely to see it simply called “Floating Lens Elements” or something similar.
RF stands for Rear Focusing, and is often seen in wide angle primes. This means that the rear element moves when focusing, allowing the front to stay fixed. This makes it easier to have the lens provide good image quality, while not changing the outward size of the lens. This is another thing that’s not typically listed in the name, but you might see in the specs.
Super Integrated Coating isn’t typically listed in the lens’s name, but is often found in the specs of high-end lenses. It’s similar to nano coating, in that it reduces flare and improves colour transmission.
HRI stands for High Refractive Index, and they allow for more extreme light gathering than normal glass. This allows for smaller, lighter lenses, and better correction of issues like spherical aberration.
AS means Aspherical lens elements, and these elements are great for correction distortion, coma, and other issues, while reducing lens weight and size. However, aspherical elements can cause issues with bokeh quality, so they’re rarely used in fast primes.
ASED stands for Aspherical Extra-low Dispersion, which is basically a higher quality aspherical element that better corrects colour fringing, coma, and other aberrations.
ML stands for Meniscus Lens, which is a curved glass element used to prevent ghosting.
SWM stands for Silent Wave Motor, the ultrasonic autofocusing motor in AF-S lenses.
Not to be confused with fluorite elements, fluorine coating is a coating applied to the glass that repels dust and water, making the lens easier to clean and less susceptible to grime sticking to it. It’s used on the front and/or rear element of some of Nikon’s highest quality lenses.
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Lauchlan Toal is the creator of UnlockCreativePhotography.com, and a Halifax based food photographer. Outside of food photography, he enjoys most genres, finding fun in any kind of photography challenge.