[Some] Photography Abbreviations Terminology Explained

When a consumer is in the market to purchase a new lens, what do they look for? Are they looking for the 80-350mm f/1.8-3.5 STM VR HSM DO DC DX SWM Micro? Probably not (and not just because that's not a real lens). If asked what lens was used when shooting, the photographer/videographer usually only gives two pieces of information: the focal length and the maximum aperture. These two factors have biggest effect on what their images and video will look like, as these factors directly affect angle of view, depth of field, etc.

So is the rest of the mumbo-jumbo important? Of course it is; why would they include it otherwise? Often times, that tells us exactly which version of the lens is. For example, if you were shopping for a simple Canon 18-55mm kit lens, that's great. Now which one? There are nine:

Note: This image doesn't even include the most recent version of the lens, either!

While "EF-S18-55mm f/3.5-5.6 IS STM" seems like a mouthful, all of the pictured lenses do share the same focal length and maximum aperture range: 18-55mm f/3.5-5.6. The little suffixes at the end ("IS" and "STM") make all the difference in knowing whether you're getting the most recent version, or an oldie from sixteen years ago.

Beyond knowing what version the lens is, each of those little codes at the end has a meaning, and it usually points to a specific feature used in the lens. For example, the "IS" refers to "Image Stabilization," which is a common feature in more modern Canon lenses, and a lens without that "IS" in its name likely wouldn't have the Image Stabilization. All different lens manufacturers (Canon, Nikon, Fujifilm) have their own codes, though often times the features are similar to each other. Below, you'll find some terms and tech you're bound to see when shopping for new lenses, so we'll break down what they mean, as well as tell you how each manufacturer references it.

Auto Focus

An often underrated feature, depending on who you are. Plenty of photographers learned to shoot without it, so obviously, it's not a necessity. But when it comes to native lenses, it's much more commonplace to for newer lenses to have auto focus as a feature.

• Canon uses EF, which is short for electro focus. Since the EF mount has existed from the film days with autofocus in mind, any lens with EF-mount should autofocus on any EF-mount Canon body.
• Nikon uses AF, which short for auto focus (example: AF Zoom-Nikkor 28-80mm f/3.5-5.6D). It should be noted that "AF" is the most basic form of autofocus that Nikon offers. Nikon's first autofocus lenses are focused using a screwdrive on the rear of the lens. Ultimately, this means that auto focus was originally only possible with bodies that had their own autofocus motor. Minolta A-mount lenses also use AF on their autofocus lenses.

Obviously there will be exceptions, but more often than not, lenses nowadays are typically made with autofocus in mind, unless it's a specialty lens (like a tilt/shift lens, which we'll talk about down below).

In-Lens Autofocus Motor

Even if the lens does allow for autofocus, it's not necessarily going to be compatible with all camera bodies.

• Nikon's first lenses to include a focus motor in the lens were designated using AF-I (the "I" stands for Integrated). There are only a few AF-I lenses available, and most of them are longer primes (greater than 200mm, give or take).
• Canon's digital lenses, by default, offer a focus motor within the camera, unless it's a specialty lens that is only manual focus.

The majority of motors in lenses tend to be either ultrasonic motors or stepper motors.

Ultrasonic Motors

Ultrasonic motors are fast and snappy. It was the golden standard for the longest time, and more often than not, there'll be an ultrasonic motor in the top professional-grade lenses.

• Canon uses USM, which is short for UltraSonic Motor.
• Minolta and Sony use SSM, which is short for SuperSonic-wave Motor, on their A-mount lenses.
• Nikon uses SWM, which is short for Silent Wave Motor. But on the lens, anything that says "AF-S" uses their Silent Wave Motor.
• Olympus uses SWD, which is short for Supersonic Wave Drive.
• Panasonic uses XSM, which is short for eXtra Silent Motor.
• Pentax uses SDM, which is short for Supersonic Dynamic Motor.
• Sigma uses HSM, which is short for Hyper Sonic Motor.
• Tamron uses USD, which is short for Ultrasonic Silent Drive, but also PZD, which is short for PieZo Drive.

Stepper Motors

Stepper motors are a fairly recent technology for camera lenses. Lenses containing a stepper motor are considerably quieter than a lens using an ultrasonic motor, without compromising for speed, and because of that, are typically upsold to people that have an interest in video.

• Canon uses STM (short for STepper Motor) for lenses that use a stepper motor.
• Nikon uses AF-P (the "P" is for Pulse) for lenses that use a stepper motor.
• Pentax uses PLM (short for PuLse Motor) for lenses that use a stepper motor.
• Sigma uses DN (short for Digital Neo) for lenses that use a stepper motor.
• Tamron uses RXD (short for Rapid eXtra-silent stepping Drive) for lenses that use a stepper motor.

There are some growing pains and these new benefits don't come without a drawback. First of all, while they do support manual focus, it's not mechanically coupled, so if you're used to pulling focus manually, it may be easy to get past your area of focus. Stepper motors are also considered "focus-by-wire," so while they still need electronic connection to focus (not new), electronic connection is also required to manually focus (definitely new). If you're the type to adapt lenses onto other camera systems, you'd probably want to avoid using a lens with a stepper motor, unless the adapter you're using has electronic contacts.

Image Stabilization

Whether it's caused by shaky hands, a slow shutter speed, or a quick jostle from another pedestrian, camera shake is the bane of anyone seeking a crisp, sharp, in-focus photo. It's not something you can really fix in post-production, so if it was a critical moment, the shot is lost. Thankfully, lens manufacturers have got you covered:

• Canon uses IS, which is short for Image Stabilization.
• Fujifilm uses OIS, which is short for Optical Image Stabilization
• Nikon uses VR, which is short for Vibration Reduction.
• Pentax uses SR, which is short for Shake Reduction.
• Sigma uses OS, which is short for Optical Stabilization.
• Sony uses OSS, which is short for Optical SteadyShot, in their E-mount system. In the past they'd also used SS (SteadyShot), SSS (Super SteadyShot), and even SSI (SteadyShot Inside). No, I'm not making that up.
• Tamron uses VC, which is short for Vibration Compensation.

Image Stabilization usually boasts at least two stops

APS-C Format

Well, this isn't really much of a feature, in the conventional sense of the word. In all honesty, any lens that works on full-frame would surely work on a crop-sensor camera. Though, while a 24-70mm lens on a full-frame makes a normal zoom, it's usually too long, even at the short end, so a crop-sensor lens may end up being a better fit for you (even still, I personally find myself using full-frame glass more than crop-sensor glass on my D500). If you shoot on a crop-sensor system and have no intention of every upgrading into the system's full-frame equivalents, then you may be able to save a lot of money by sticking to the APS-C lenses.

• Canon uses EF-S for their APS-C DSLR lenses. Similarly, Canon's EF-M mount lenses are also also only for the APS-C format, but the EF-M probably doesn't double as a designation for APS-C.
• Minolta uses V for their Minolta Vectis lenses.
• Nikon and Tokina both use the DX notation for APS-C lenses. When Nikon eventually released its mirrorless Nikon Z line, they continued using DX as their APS-C designation, and for their full-frame lenses they use "FX" instead.
• Nikon uses IX for their lenses for their Pronea APS-C film cameras.
• Pentax uses DA for their APS-C lenses
• Sony uses DT for their APS-C lenses on the Sony A-mount system.
• Sony uses E for their APS-C lenses on the Sony E-mount system, and an FE notation for their full-frame lenses.
• Sigma uses DC for their APS-C lenses, and a DG notation for their full-frame lenses.
• Tamron uses Di II for their APS-C DSLR lenses, Di for their full-frame DSLR lenses and Di III for mirrorless system lenses, regardless of sensor size.

If you only have full-frame cameras, it's in your best interest to avoid lenses designed specifically for crop-sensor cameras. While some of them may actually have an image circle that's big enough to cover a full-frame sensor size, most will just give you some drastic vignetting. So always look closely before you hit that "Add to Cart" button.

Tilt/Shift Functionality

Tilt/Shift lenses are a super technical specialty lenses that let the user make adjustments to the image, as in the way a view camera's movements work. This makes them fairly popular with the architectural photography crowd, with how easy it is to make simple adjustments. Shift movements move a lens parallel to its plane of focus, while tilt movements change the angle of the plane of focus (effectively bringing the plane of focus out of parallel with the sensor plane). Older film lenses typically only offered shift movements, except for Canon's 35mm TS 35mm f/2.8, which did offer tilt functionality. Most digital-age lenses in this category tend to offer both shift and tilt.

• Nikon refers to their tilt/shift lenses as PC, which is short for perspective control (example: PC Micro-NIKKOR 85mm f/2.8D). Their original PC lenses only offered the shift movements at the 28mm and 35mm focal lengths. Most of the newer Nikon tilt/shift lenses are instead referred to as PC-E (E for electronic aperture control), though the most recent 19mm returns to the PC moniker.
• Canon refers to their modern tilt/shift lenses as TS-E ("TS" for tilt/shift, and "E" for electronic aperture control as well).
• Schneider seems to use a combination of Nikon and Canon's and refers to their tilt/shift lenses as PC TS. Interestingly enough, Schneider is also the only manufacturer to not use a knob to control adjustments. Instead, they opt to use different rings that can be turned to tilt or shift.

For good reason, these lenses are typically going to only be manual focus, so they won't have their typical AF or EF markings. They're complex enough, with the extra knobs, controls, and electronic aperture control, so I wouldn't even dare to ask for one with autofocus. Also, imagine how much that'd drive the cost up!

Focus Clutch

A focus clutch is typically built into the manual focus ring. When the mechanism is not engaged, turning the focus ring actually doesn't do anything. Pulling the focus ring back towards the camera engages the clutch mechanism, and you can manually focus as usual after that. If you're used to keeping a hand on your lens to focus (or even to support your lens or change aperture, depending on if your lens has an aperture ring), a focus clutch will probably feel nature. However, it might disrupt your flow if you're used to having manual focus override or a flipping switch on the lens or or camera body.

• Tokina uses Pro in the lens name for any of the AT-X or AT-X V-series lens that includes its focus clutch. Certain lenses in the atx-i and Opera series also have the clutch, but they have a special abbreviation for it.
• Both Olympus and Fujifilm do incorporate focus clutch mechanisms in select lenses, but they do not use any sort of acronyms to reference it.

Though plenty of lenses offer both manual and autofocus, the way a system changes between the two can make all the difference when it comes to handling. Focus clutches are certainly less common, but across the board, different manufacturers use all sorts of the different ways to toggle between manual focus and autofocus:

• Dials: Having a physical dial on the camera to switch your focus type can be nice, if you're toggling between three options (even though some Nikons only toggle between AF and MF). You may see dials on select Nikon, Fujifilm, Pentax, and Panasonic cameras.
• Switches: Switches make more sense if you only need to switch between two available settings. Switches can be found on Minolta and Sony A-mount cameras, select Pentax cameras, and many lenses tend to also include a switch to change between autofocus and manual focus.
• Buttons: This is somewhat misleading, as this implies that only the button is used to cycle through your options, but in actuality it involves pressing (or holding) a button, and changing the setting(s) with your command dials. This style of switching focus modes can be seen in select Canon and Nikon cameras.
• Camera menus: This is probably my personal least-favorite when it comes to switching between manual and autofocus as it can break a photographer out of the flow of shooting. From a design aspect, however, it does means less dials/buttons/switches to incorporate. Switch between AF and MF through the menu on select Nikon, Canon, Fujifilm, and Sony cameras.

Weather Sealing

Unfortunately working with photography or video doesn't guarantee you beautiful weather. Conditions that may be safe for you to shoot in aren't always as forgiving to your camera equipment. Thankfully [some] lens manufacturers have you covered.

• Pentax and Fujfilm use WR (short for Weather Resistant) on select lenses that have weather sealing.
• Nikon and Pentax use AW (short for All Weather) on select lenses that have weather sealing.

Don't see your brand listed? Fear not; plenty of modern lenses have some form of weather sealing. But in most scenarios, it's not referenced, unfortunately.

Final Thoughts

One could certainly argue that having these endless prefixes attached to lens names is just a marketing tactic. And that'd definitely work, as long as only a select few competitors are offering a certain feature. However, with camera and lens companies slowly converging into using a lot of the same technologies, why even bother advertising a feature? Hopefully, they have consistency in mind. If they have naming conventions set for specific features, it's best to keep up with it, as the last thing you need is to start confusing your customers and prospective buyers. Plus, if a customer is looking and may already be familiar with their offerings, using the shorthand in the lens titles is a good way to see if a lens has a feature they need (or don't need).

Now with all of this new, confusing, verbose knowledge that you may have already known before even before reading this article, are you a better creator? Probably not. But if you did learn something new here, it does make you a more knowledgeable consumer, which is always helpful when looking at new gear.