Large aperture - f/2Fast autofocusL-series construction and opticsSoft BokehIntegration with E-TTL II flash system
The lens' large maximum aperture lets photographers shoot with relatively fast shutter speeds, even in low light. This makes the EF 135mm f/2.0L USM an ideal optic for those shooting indoor sports. Despite its high specification, the lens is relatively lightweight and compact, weighing just 750g.
A ring-type ultrasonic motor drives autofocus extremely quickly, and in near silence. Excellent holding torque ensures the point of focus is reached accurately, without overshooting. Furthermore, full-time manual override is available, making it possible to adjust focus without leaving AF mode.
A large maximum aperture of f/2 provides outstanding speed for shooting in low-light conditions without the need for flash. The large aperture also provides fine control over depth of field.
The L-series is Canon's flagship professional lens range, representing the best in precision-designed EF optics. L-series lenses combine superior performance with superlative handling, and are resistant to dust and moisture.
Even if the background is very close to your subject, somehow the optical construction in the 135mm lens will still manage to separate the background beautifully.To achieve this creamy bokeh, a lens should have a wide maximum aperture and a long focal length. Never before have I seen a lens with this level of sharpness wide open. Perhaps this impression of unreal sharpness is strengthened by the contrast to the extremely bokeh you typically get in the same photo.It is harder work than using a zoom lens, and some shots I just cannot get at all (cannot get close enough, or far enough way) but the shots I do get are so much nicer looking than I get with any other lens that for me and my goals it is a fair trade off.