“L” stand for “Luxury“, L Lens or normally called L-series lens is the most expensive and highest quality lens among the lenses made by Canon.

In general, L lenses are
- Tough build (made to withstand the trials on the fields, and some incorporating dust and moisture resistant rubber seals)
- Focus faster (The wide maximum apertures and fast, quiet USM motors enhance focusing speed)
- Offer higher optical quality (contrast, sharpness, color, background/foreground blur quality, flare, Chromatic Aberration)
- Normally the lens come with white color (according to Canon, this reduces heat gain when a lens is used in bright, direct sunlight)
- Full time manual focusing, FTM (you can let the camera autofocus, then manually adjust focus yourself prior to the shot)
- At least one fluorite or ultra-low dispersion glass element (fluorite crystal rather than normal glass), combined with super-low dispersion glass and ground aspherical elements
- Non-rotating front elements, which are optimal for some filters
- Expensive.

The presence of a red ring around the end of lens barrel that indicates an L lens, if it is made by Canon.