Canon Camera and Lens Terminology and Meanings

FD

Canon's unique breech-lock mount.
It was perfected after the R-mount and FL-mount. All are breech-lock type and have the same shape, so they can be mounted, but there will be limitations in the联动機能 with the camera body. (e.g., automatic aperture)
Each can be identified by the FD, FL, etc. in the lens name.

New FD

A series of lenses that can be mounted by rotating the lens, similar to a bayonet mount.
The word "New" is not included in the lens name, but it can be identified by the appearance of the lens.

L

The initial of Luxury, given to high-end lenses.
Characterized by the red ring at the front of the lens.

S.C.

Spectra Coating
The name for multi-coating.

S.S.C

Super Spectra Coating
An advanced version of S.C.
It is included in the name up to FD lenses, but all lenses from New FD onwards have this coating.

Demi

A series of half-frame compact film cameras.

Autoboy

A series of autofocus compact film cameras.

EOS

Abbreviation for Electro-Optical System.
The name of an autofocus SLR camera system.
It has continued from film cameras to current digital SLRs.

EF Mount

Canon's unique bayonet mount adopted in the EOS camera system.

EF-S

Lenses and mounts exclusively for camera bodies equipped with APS-C size sensors.
It is exclusively for digital SLRs. It cannot be used with film SLRs or full-frame digital SLRs.

EOS M

A series of compact mirrorless cameras.

EF-M

A series of lenses for the EOS M series.
Also called the EF-M mount.
It is not compatible with EF mount camera bodies.

IS

Abbreviation for Image Stabilizer. Refers to image stabilization.

USM

Abbreviation for Ultrasonic Motor.

STM

Abbreviation for Stepping Motor.

DO

Abbreviation for Diffractive Optics. Refers to diffractive lenses.
Chromatic aberration can be corrected by combining it with a refractive lens.
Lenses can be made smaller and lighter than if DO is not used.
It is characterized by a green ring on the exterior of the lens.

UD

Stands for Ultra Low Dispersion.
By equalizing the refractive index, a state of high resolution with little color fringing can be achieved.

BR

Abbreviation for Blue Spectrum Refractive.
Enhances the level of chromatic aberration correction, contributing to improved resolution.

TS-E

Lenses capable of tilt-shift photography.