Decoding The Text Around Your Lenses

Have you ever found yourself looking at all the writing on your lens and feeling overwhelmed, and intimidated? Instead of ignoring all that writing, you should be using it to your advantage!

 I know what you're thinking - "Text around my lens?  You mean all those numbers and things to make the lens look all fancy and high tech?" Yes that!  All that writing is vital to your photographic endeavors.  Not only does it tell you what your equipment is capable of, but it also tells you what kind of shots you can get. In this short post we'll look at each piece of information on your lens and what it means.  

Focal Length

Your focal length is the most important number on your lens.  It determines your field of vision (how much you'll see) when you look through the camera, and it's measured in mm. You'll find the number in 2 places either on the side where it will say something like 17-40mm or they will be listed around the zoom ring. Here's the general breakdown:  

  • Teens to about 35mm is considered wide angle.  That means you can see a lot when you look through the camera.
  • 35mm-85mm is considered standard focal length.  50mm is considered the standard focal length.  That means when you look through the lens it feels very natural, like eye sight.  Not wide and distorted, not cramped and zoomed in.
  • 85mm or higher is considered telephoto - 100mm, 250mm, 400mm, etc.  Telephoto gives you a very zoomed in and "tight" frame without as much context around your subject.

Maximum Aperture

This is the second most important piece of information is the maximum aperture.  This can be found on the front of the lens (and sometimes on the top also). You'll see something with a 1: then a decimal, like 1 : 3.5-5.6 or 1 : 1.8.  The decimal part after the colon is what you want to worry about.  

Now, this is more complicated than focal length. Explaining maximum aperture without giving you a full on lesson on the fundamentals of photography would be difficult, so here's the gist: The lower the number, the better.  When you have a low maximum aperture it lets more light into the camera so you can get better shots in low light (that birthday party when Jimmy is blowing out his 4 candles).  In addition to that, you know that blurry background everyone loves?  The lower that number, the more blur you'll get - ideally 2.8 or lower. 

⌀ Filter Size

Filters are pieces of glass on the front of the lens that manipulate the light coming into the camera.  For the most part, people use Photoshop to filter images these days, but there are a few filter types that people still use regularly (UV, Polarizing, ND).  The Filter Size mark is usually on the front of the lens or on the bottom.  It's identified by a circle with a line through it and a number like ⌀49.  The number is simply the diameter of the front of your lens.  So if you see ⌀77, you need a "77 filter".  

Now, even if you're just starting out, there's one filter that everyone should have on their lens, and that's a UV filter.  A UV filter will say it does a bunch of stuff for your images, but that's mostly marketing.  The real purpose of a UV filter is protection.  By adding a UV filter to your lens 1) It helps prevent dust and moisture from getting on the glass elements and 2) If, God forbid, you accidentally drop your lens 😱  the shock can sometimes travel through the lens and crack the filter instead of the glass inside. 

Minimum Focal Distance

The minimum focal distance is a meter/foot measurement that can be anywhere on your lens so you'll have to look around for it.  If you have a window at the top of your lens, it's the numbers inside the window.  It will look something like 0.35m/1.1ft.  That number tells you the closest you can be to your subject before your lens physically can't focus anymore.  

If you've ever tried to take a close up and your lens just keeps going back and forth like "reahhhhh reahhhhhhhh" (play the sound effects in your head for full effect), you've exceeded your minimum focal distance.  And try as you might, that lens will never focus.  If that happens, simply reference that number and move back until you can get your focus.  

AF/MF & Image Stabilization

This is a simple one.  On the side, if you see a switch AF/MF or A/M, this refers to auto-focus.  The AF or A is auto-focus, the MF or M is manual focus.  Unless you like manually focusing your images, I would suggest just leaving this on the AF setting.  This is also a good setting to check if you are trying to focus and your camera isn't responding.  You may have bumped the switch and set it to manual focus on accident. 

Image Stabilization will be another switch adjacent to the AF/MF switch.  There isn't a standard notation.  Sometimes it's called IS, VR, Stabilizer, Optical Steady Shot (OSS), or any other name similar to those.  This refers to a little motor in your lens that helps reduce the blur you get in low light pictures.  I would suggest just leaving this on.  Honestly in a kit lens (the one that came with your camera), these are more just for marketing, and won't make a huge difference in your images.  But if you purchase a high end lens with stabilization, it can make the difference between a blurry photo and a sharp one.

Mount Type & Other Marks

The last one here can get a little complicated, so I'll keep it simple.  You may find a variety of other letters on the front of lenses, and they all very based on the brand.  A quick Google search for any letters you don't know and the brand of the lens will give you the info you need but here's a few that you might run into.

Canon: EF or EF-S  This refers to their modern lens mount (the part that attaches to the camera).  An EF mount is used for all modern Canon lenses.  Their previous mounting system from back in the 70's was called an FD mount.  The difference between EF and EF-S, the "S" on the end refers to the lens being made for crop sensor cameras.  We won't dive into the difference between crop sensor and full-frame here, but that's the the only difference between the two.  Both are EF mounts, but EF-S is made only for crop sensor cameras.

Nikon: FX or DX  This is the same as EF or EF-S above.  FX refers to the standard full-frame mount like EF.  DX stands for their crop sensor mount.  

One other mark on Nikons to note is AF-S .  If you have a more introductory camera body, make sure to purchase AF-S lenses.  AF-S refers to the an auto-focus motor being inside the lens.  The lower end Nikon camera bodies don't have an auto-focus motor built in, so it requires the lens to have one in order to auto-focus.  If you don't buy and AF-S and your camera body doesn't have an auto-focus motor inside, then the lens will be fully manual focus.

Sony: E or FE  This is the as the EF/EF-S & FX/DX marks above.  E refers to their crop sensor mount and FE refers to their full-frame mount.  

It's a lot of information to take in, and if you're not actively practicing photography on a regular basis, it's easy for that stuff to slip out of your mind.  Some things may even be written on there that we didn't cover in this post.  Luckily if you run into some unknown numbers and letters, most of that information is simply reference and is no further and a quick Google search away.  If nothing else, just remember the 2 most important things to remember are the focal length and maximum aperture.  There's a reason why those 2 stats make up the lens name when you buy it!