Decipher all the jargon and buy your DSLR lens with confidence!

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For beginners, choosing a new lens can be an absolute minefield. It can feel like you’re playing Scrabble when reading some of the names!

After reading this you’ll have the knowledge and confidence to make an informed decision; so you can nullify the minefield, and make the right investment for you.

When shopping for lenses or looking at them in person, you’ll often see the full name written like this…

Nikon AF-S Nikkor 28-300mm 1:3.5-5.6G ED VR | Nikon AF-S Nikkor 50mm f/1.4G

Nikon AF-S DX Nikkor 16-80mm f/2.8-4E ED VR | Canon EF-S 18-55mm f/3.5-5.6 IS STM

Canon EF 24-105mm f/4L IS II USM

Each bit refers to a different feature of the lens to let you know how it will behave. I’ll be using these lenses as examples because their names incorporate a wide range of naming practices, so let’s begin decipher them!


Nikon and Canon

Nikon AF-S Nikkor 28-300mm 1:3.5-5.6G ED VR | Canon EF 24-105mm f/4L IS II USM

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I’m not being flippant, but this is the manufacturer of the lens. It might seem obvious, but each manufacturer has their own proprietary eco-system of products, and it’s important to know to which system the lens belongs because competing products don’t play well with others.


AF-S, USM and STM

Nikon AF-S Nikkor 28-300mm 1:3.5-5.6G ED VR | Canon EF 24-105mm f/4L IS II USM | Canon EF-S 18-55mm f/3.5-5.6 IS STM

AF-S

AF-S

It really is like playing Scrabble reading these lenses!

It really is like playing Scrabble reading these lenses!

Even though they are at opposite ends of the names, I’ll discuss AF-S, USM and STM together here as they refer to the same thing. On the Nikon, AF stands for Auto Focus, which means the lens uses a motor to focus automatically; while the S stands for Silent Wave Motor (SWM): meaning the motor is silent. Canon’s USM stands for Ultra Sonic Motor, and again means the lens will focus silently. STM is Canon’s newer Stepper Motor technology. The USM lenses are silent, but the STM lenses are like, super-duper silent; and smoother. 

Older lenses without silent motors omit a loud mechanical whirring noise as the motor works. Silent AF is extremely desirable when you need your photography to be as quiet as possible like during a wedding.


Nikkor and EF

Nikon AF-S Nikkor 28-300mm 1:3.5-5.6G ED VR | Canon EF 24-105mm f/4L IS II USM

Gold Nikkor text showing signs of use

Gold Nikkor text showing signs of use

Nikkor and EF refers to the lens mount, and lets you know specifically which type of Nikon and Canon camera the lens works with. The lens mount is the metal or plastic ring at the base of the lens that mounts to the camera. Canon’s EF lens mount was introduced alongside the EOS camera mount back in 1987, so the EOS and EF mounts work perfectly together. If you come across a bargain while browsing used Canon lenses, be careful to check the mount. If the price seems too good to be true, it’s probably an older FD mount lens, which won’t mount with the EOS DSLRs.

Rear lens cap letting you know the lens is for the Nikon F-Mount

Rear lens cap letting you know the lens is for the Nikon F-Mount

Nikkor lens mount for Nikon F-Mount DSLR cameras

Nikkor lens mount for Nikon F-Mount DSLR cameras

On the Nikon side, the Nikkor lens mount works perfectly with Nikon’s F-mount. Unlike Canon, Nikon don’t state the mount in the camera’s name, probably because the F-mount dates all the way back to 1959; and has the largest amount of compatible lenses in history. Despite the vast degree of forwards and backwards compatibility though, I still highly recommend you check the lens’ full documentation to avoid problems.


DX and EF-S

Nikon AF-S DX Nikkor 16-80mm f/2.8-4E ED VR | Canon EF-S 18-55mm f/3.5-5.6 IS STM

What happens when you put a DX lens on an FX camera.

What happens when you put a DX lens on an FX camera.

On some Nikon and Canon lenses, you’ll also see DX and EF-S respectively. DX and EF-S lenses are designed to work specifically on DSLRs with smaller sensors. The DX lenses use the F-Mount, and will work perfectly on DX model cameras. They’ll still mount to an FX camera, but you will get an image that looks like this. Canon’s EF-S lenses can’t be mounted to EOS DSLRs with a larger sensor; so if you own a camera with a larger 36x24mm sensor, check a lens isn’t EF-S before you invest.


28-300mm, 18-55mm, 24-105mm, 16-80mm and 50mm

Nikon AF-S Nikkor 28-300mm 1:3.5-5.6G ED VR | Canon EF-S 18-55mm f/3.5-5.6 IS STM | Canon EF 24-105mm f/4L IS II USM

Nikon AF-S DX Nikkor 16-80mm f/2.8-4E ED VR | Nikon AF-S Nikkor 50mm f/1.4G

This lens’ name can be abbreviated to just ‘The 28-300’ i.e. “Pass me the 28-300 please”

This lens’ name can be abbreviated to just ‘The 28-300’ i.e. “Pass me the 28-300 please”

And now we get to everyone’s favourite part of photography: the numbers. On lenses you’ll see measurements in millimetres, these numbers refer to the focal length range of the lens. The focal length is the lens’ magnification and angle of view. A smaller number like 28mm means a low magnification, and a wider angle of view (zoomed out), so you see more of the scene. The higher number like 300mm means a higher magnification and a narrower angle of view (zoomed in). Lenses with the ability to zoom in and out like this are called zoom lenses.

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28mm: low magnification (zoomed out) produces a wide angle

28mm: low magnification (zoomed out) produces a wide angle

300mm: high magnification (zoomed in) produces a narrow angle

300mm: high magnification (zoomed in) produces a narrow angle

You can see how the barrel extends to acheive 300mm

You can see how the barrel extends to acheive 300mm

Lenses with only 1 focal length like the 50mm are called prime or fixed lenses. Fixed meaning fixed focal length, and therefore cannot zoom.


1:3.5-5.6, f/4, f/2.8-4 and f/1.4

Nikon AF-S Nikkor 28-300mm 1:3.5-5.6G ED VR | Canon EF 24-105mm f/4L IS II USM | Nikon AF-S DX Nikkor 16-80mm f/2.8-4E ED VR

Nikon AF-S Nikkor 50mm f/1.4G

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Wow, okay. This looks confusing but have patience and bare with me. 

The numbers after the focal length refer to the lens’ maximum aperture. The lens’ maximum aperture is the maximum amount of light it can let through and is specified in f-numbers, hence the f before the numbers on most of the lenses.

I say maximum aperture because just like your eye’s pupil, apertures becomes smaller to let less light in: and bigger to let more light in. The smaller the number, the more light a lens can let in. So a lens with a maximum aperture of f/1.8 can let in more light than a lens with a maximum aperture of f/4. Still with me?

The reason there are 2 f-numbers in most of our example lenses like f/3.5-5.6 refers to the fact that as the lens zooms, the maximum aperture narrows from f/3.5 to f/5.6. So at its widest focal length, the lens can let in more light, and f/3.5 will be the maximum available to use. As you zoom in however, you will find f/3.5 becomes unavailable, and f/5.6 becomes the new maximum aperture. Lenses like this are referred to as variable aperture lenses. 

Fixed lenses with only 1 focal length will only have 1 aperture value stated. But you will notice that even though the Canon 24-105mm F/4 is a zoom lens, it too only has 1 aperture value stated. This is because the lens is able to retain its maximum aperture throughout its zoom range. This is referred to as a constant aperture zoom lens, which are often much more expensive than their variable aperture counterparts.

Lenses with large maximum apertures are desirable because they let in more light, which is useful in darker situations.

f/3.5

f/3.5

f/36

f/36

Pro tip: Using a large aperture will cause the out of focus areas of an image to blur significantly, so if you’re looking for that sweet foreground/background blur, look for lenses with large maximum apertures like f/1.8 or f/2.8.

And breath. Aperture can be a little tricky to get your head around initially. The main take away here is that the smaller the lens’ f-number, the more light it can let in. Lesson 1 of my Portraits Like a Pro photography course contains a comprehensive explanation of aperture, and is available here for free.

By the way, sometimes you’ll see the f-numbers as a ratio (1:3.5-5.6) because f-numbers are the ratio of focal length to aperture diameter. It’s not necessary to know this, but it’s written on the lens so I thought I’d mention it.


G and E (and maybe D)

Nikon AF-S Nikkor 28-300mm 1:3.5-5.6G ED VR | Nikon AF-S Nikkor 50mm f/1.4G | Nikon AF-S DX Nikkor 16-80mm f/2.8-4E ED VR

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On most newer Nikon lenses you’ll often see the single letter G after the maximum aperture value(s). This simply means that there is no manual aperture ring on the lens. If you come across an older D lens you’ll see it has a ring for manually selecting the aperture. You can pick up D lenses cheaply, but be aware some functionality like AF may not work on certain DX cameras. 

E type lenses are even newer, fully electronic lenses. On G and D lenses, the camera controls the lens’ aperture via a small mechanical lever in the mount. E lenses omit this lever, and the aperture is controlled electronically, probably so Nikon can remove the aperture lever from future cameras.

The small aperture lever on the mount controls the aperture blades

The small aperture lever on the mount controls the aperture blades

Pulling it on this 50mm opens up its massive f/1.4 maximum aperture

Pulling it on this 50mm opens up its massive f/1.4 maximum aperture


L

Canon EF 24-105mm f/4L IS II USM

On Canon lenses, the L stands for Luxury, and signifies a premium quality lens with higher quality optics like a-spherically ground, fluorite or ultra-low dispersion glass elements. They’re also more durable and weather sealed against water, dust and heat. The longer zoom lenses are also white, which reflects heat so that the lens doesn’t expand and contract in the sun. Canon’s L lenses are iconic, and instantly recognisable due to a red ring around the front.


IS and VR

Canon EF-S 18-55mm f/3.5-5.6 IS STM | Nikon AF-S Nikkor 28-300mm 1:3.5-5.6G ED VR | Canon EF 24-105mm f/4L IS II USM

Nikon AFS DX Nikkor 16-80mm f/2.8-4E ED VR

Virtual Reality?

Virtual Reality?

IS and VR stand for Image Stabilisation and Vibration Reduction respectively. They are extremely useful features that stabilise the lenses against camera shake. It can increase cost quite a bit on some models, but it’s often a necessary feature if you shoot in low light, especially with longer, heavier lenses as they’re more difficult to hold steady. Perhaps in the future VR will stand for Virtual Reality.


II

Canon EF 24-105mm f/4L IS II USM

The II means that this is the 2nd version of a lens. As lenses age, manufacturers often replace them with newer versions, allowing you to grab a bargain on the first generation.


ED

Nikon AF-S Nikkor 28-300mm 1:3.5-5.6G ED VR | Nikon AFS DX Nikkor 16-80mm f/2.8-4E ED VR

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And finally, ED. On most higher quality Nikon lenses you’ll find ED, which are Extra-low Dispersion glass elements. This means the lens doesn’t disperse the light as it enters, which controls undesirable things like colour fringing, and also delivers better sharpness.

And that’s it! We made it!

With your new knowledge, scrolling through store listings should now be a whole lot easier. Just remember: buying new lenses won’t improve your photography. The only way to improve is to learn and practice! If you are an absolute beginner, instead of investing in new glass, first invest some time into your own self-improvement and development.

For us at Prime Photographic, knowing exactly how our equipment performs in all situations allows us to quickly achieve the best photographs possible. It has taken over a decade of learning and practicing to reach this stage of absolute confidence and proficiency. And you can now give your own journey a rocket-boost because we’ve just made our 3 part Portraits Like a Pro photography course available for free. So if you enjoyed this jargon-busting, non-elitist approach to discussing photography, simply click here to subscribe to our website and receive free access to our courses, as well as regular blog updates such as these.