The Complete Canon Lens Abbreviations Glossary



Welcome to the world of photography, where geeky scientists make great lens… and use all their secret codes to confuse consumers.

Fret not, this guide will explain those EF-S, STM Canon lens acronyms and abbreviations to you, and a small history lesson to help you better understand.




Unlike Nikon which has stuck to their “F-mount” for a long time, Canon has a history of changing their mount systems.

  • 1930s to 1950s : Canon adopted Leica’s Screw Mount (LTM) system.
  • 1959 : R Mount
  • 1964 : FL Mount
  • 1971 : FD Mount. FL lens can be used on FD cameras.
  • 1987 : EF Mount (EOS series). All previous R, FL and FD mounts can no longer be used on an EF camera. But adapters are easily available.
  • 2003 : EF-S Mount, an upgraded EF mount. EF-S cameras can use EF lens, but not the other way; EF-S lens cannot be mounted on an older EF camera.
  • 2012 : EF-M Mount. A new standard for the Canon mirrorless systems, nope, these don’t mount onto the EF-S systems. Not without an adapter again.
  • 2012 : PL Mount. Which is only open to the higher end Cinema EOS cameras. Yep, these are lens meant for film production.




Canon seem to love glorifying their auto-focus motors. I don’t understand either, but here goes.

  • AFD : Arc-Form Drive. The first autofocus motor used in Canon EF lens. Slower, louder and not that fast to react… does not have manual focus override either. Which can be a pain sometimes when shooting in low light.
  • MM : Micro Motor. Basically, this is the smaller version of the AFD motor. Similarly, does not have manual focus override. The noise is audible, but not that annoying.
  • STM : Stepper Motor. Gradually becoming the “default motor” for the more budget Canon lens. Designed to be a little faster than the AFD, and less noisy for video recording.
  • USM : UltraSonic Motor. This is the current top-end focusing motor for Canon lens. Fast, quiet and powerful.
  • Micro USM : The smaller and simpler version of USM. Generally used in the smaller lens.




Canon calls their stabilization system “optical image stabilization (IS)“, which moves the lens’ elements to counter the shake. Well, not that useful when you have a sturdy tripod anyway.



  • PZ : Power Zoom. The lens has a dedicated motor for zooming (or changing the focal length). I am not too sure about this… who is too lazy to turn a ring? There’s even an adapter for power zoom – Petapixel. Power Zoom makes sense for pancake or extending lens, but for a “longer lens” which has space for a zoom ring, it’s just weird. Edit : So I have learnt, power zoom is actually very useful for video where you want a smooth zoom transition.
  • Macro : a lens designed to be able of focusing very close up to the subject.
  • Compact Macro : Not too sure if there are other compact macro lens other than the EF 50mm f2.5. Yep, it’s 50mm and it’s macro. But instead of the 1:1 full size macro, the compact is 1:2 half life size macro… a converter is available to make it full size macro though.
  • MP-E : Very high magnification lens, up to 5:1… you can call it a microscope. Again, not sure if there are other Canon lens with MP-E other than the Mp-E 62mm f2.8.
  • TS-E : Tilt-shift. This lens is unique, expensive… and manual focus only.



  • SSC : Super Spectral Coating. Basically a special lens coating that minimizes reflections and boosts contrast. All modern Canon lens are multicoated “by default”, so you will only find SSC marked on the older Canon lens.
  • DO : Diffractive Optics. Technicalities aside, lens with DO have “special glass elements”, which are said to be sharper and lighter than the regular lens. DO lens are marked by a green band, deemed to be better than the regular Joe, but slightly below the red ring “L” lens (see below).
  • Softfocus : These lens produce soft images deliberately. Well, it’s all about that retro dreamy creamy effect. No longer popular and these lens are not produced anymore. You might be interested in buying a cheap softening filter instead… or just rub some Vaseline on your UV filter.



  • L : Luxury. Spot that red ring on the lens? It is Canon’s way of saying “top of the creme lens”. Red rings are typically more expensive than their “normal” counterparts. But you can rest assure you are getting quality optics with that ring… and price.
  • Roman Numerals (I, II, III, etc…) : Canon make their lens and cameras like space ships. These Roman Numerals are simply the “revision number” or upgraded version. E.g. Canon EF 24-70mm f/2.8L II USM. Yep that “II” means it is “mark 2” of the lens, supposedly with better optics and stuff. This same Roman Numbers are applied to the cameras as well. E.g. Canon EOS 5D-III.


Related posts

Leave a Comment