The Canon EF lens mount was first introduced back in in 1987 and became
the prevailing mount for the entire Canon EOS category for both SLR film and DSLR digital cameras. The acronym EF means "Electro-Focus": EF lens auto focusing is conducted by an in-the-lens dedicated electric motor. From a mechanical standpoint it' a bayonet-type mount, and all data transmission between lens and camera occurs by electrical contact; there is no mechanical interaction
Later on Canon established the EF-S mount in 2003, an offshoot of the Canon EF mount created strictly for 1.6x crop factor digital EOS cameras. Although an EF lens may be mounted on an EF-S cropped image body, an EF-S lens cannot be fitted to an EF body.
The EF-M mount was specifically designed for the EOS M camera released in July
of 2012. An EF-M Lens Mount Adapter from canon allows you to attach EF & EF-S Canon lenses to the digital Canon EOS-M mirrorless camera, which features a Canon EF-M
lens mount. It operates fully with every lens function, including autofocus and
STM stands for Stepper Motor and is a applied to a new range of Canon lenses which feature a new design of focus motors which, along with a new iris mechanism are designed to eliminate (auditory) noise during video
A new book,
including all the variations - is a new paradigm in publishing, Disparate content sources have been
organized into a single relevant, cohesive and informative book. This content was
organized using articles from Wikipedia and images using Creative Commons licensing, Books like this one represent an exciting new lexicon in the distribution of human knowledge. This book in particular embraces chapters focused upon the various Canon lenses, including EF-S lenses, EF lenses, FD lenses, kit lenses, FL lenses, and L-Series lenses.
An offshoot of the EF mounting system, Canon added the EF-S lens support, in 2003, designed only for EOS digital cameras featuring a 1.6x crop produced after 2003. Any other Canon EOS camera that features an EF mount only will not permit mounting of EF-S lenses.
Canon EF-S 55-250mm f/4-5.6IS. - for
EOS digital SLR cameras. Plastic build right down to the lens mount. In fact, there's so much plastic, this lens feels looks and looks af the label should read Playskool and not Canon. but, looks can sometimes be somewhat deceiving. Just get on with using it, and quit pixel peeping already. If you have a need for a metal lens mount, perhaps you are somewhat too violent with your gear and you should look for a Hummer or
brand camera. Updated 01/02/2011 ✓
T2.6 L S / CN-E14.560mm T2.6 L SP - Announced
Nov 4, 2011
T2.953.7 L S / CN-E30300mm T2.953.7 L SP -
Announced Nov 4, 2011
T1.5 L F / CN-E50mm T1.3 L F / CN-E85mm T1.3 L F
- Announced Nov 4, 2011
USM = Ultrasonic Motor. Ring USM motors are silent and manual focus (FTM = Full Time Manual) is possible without switching out of autofocus. Micro USM motors are quiet, but do not allow full time manual focus.