L Series lenses

Notice the telltale red ring on these two Canon L series lenses.

The L in Canon’s high-end lenses stands for “luxury.” L series lenses are easily identified by the telltale red ring around the end of the lens barrel (shown in 6-4). These flagship optical marvels are expensive, but provide unrivaled quality, speed, and precision. Canon has designated L series lenses for professional use, although many consumers, enthusiasts, and semipros also use them. The L is included in the product name just after the lens speed (aperture) rating, as shown:

  • Canon EF 500mm f/4L IS USM
  • Canon EF 28-300 f/3.5-5.6L IS USM
  • Canon EF 85mm f/1.2L II USM

Canon achieves the quality — and demands the corresponding price — for L series lenses by integrating superior technology in them. Here are some of the advantages:

  • Low-dispersion Ultra Low Dispersion (UD) glass
  • USM operation
  • Aspherical glass
  • Weather resistance
  • Nonrotating front elements (which helps when using rotating filters, such as polarizers)
  • In some models, a fast (large, nonvariable aperture) lens speed
  • Full-time manual focusing (meaning it can operate interactively while using autofocusing)

About 25 of Canon’s lenses are rated as L series lenses, although Canon is frequently discontinuing as well as adding models. Many of the lenses are distinctive in their white coloring, which always stands out when you see a group of photographers at an event. Canon uses the white color on longer lenses that are often used outdoors because it resists heat from the sun, which could affect lens performance.

In addition to knowing what the L in the lens name means, knowing these other labels can help you quickly identify characteristics of a lens.

  • EF. These are lenses built for Canon’s EOS system, and the acronym stands for electro-focus. It is now a standard term for any Canon lens with an electronic focus. If a lens doesn’t have an EF in the name, it doesn’t offer this feature.
  • IS. The IS indicates that the lens offers image stabilization. This gyroscopically controlled technology is used in some of the telephoto lenses to allow photos to be taken at slower shutter speeds without camera-shake blurring the photo.
  • USM. This stands for ultrasonic motor, which is the autofocusing mechanism in Canon lenses. It is the high-end, ultraquiet motor Canon has developed for higher-end lenses.


EF-S lenses are only compatible with the new Canon lens mounts on cameras with this specification. EF-S-compatible cameras, which are more consumer oriented, also support EF lenses.

Category: Science of Lenses

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