Understanding Canon’s EF lens codes

Each EF (Electro Focus) lens is identified by a series of codes which provides important information about its unique characteristics. For example:

Other classification acronyms

All of these acronym classifications usually appear at the end of the lens specifications and denote specialist features:

MP-E

Lens specially designed for macro photography.

TS-E

Specialist tilt/shift lenses that allow correction of perspective distortion and control over the angle of the focal plane. These lenses are often used for architectural interiors and exteriors.

Extender

Lenses that fit between the camera body and the master lens to deliver focal length magnification.

EF-S

In 2006 Canon introduced a variation on the standard EF lens mount called EF-S. The ‘S’ stands for ‘Short Back Focus’. These lenses are designed for the EF-S lens mount on cameras featuring a 1.6x FOV APS-C size sensor e.g. 1000D, 450D, 40D and 50D. An EF-S mount is compatible with all EF lenses and EF-S lenses. However, EF-S lenses are not compatible with an EF mount.

DO (Diffractive Optical elements)

This technology is unique to Canon and enables the manufacture of smaller, lighter high performing photo lenses. DO indicates the use of multi-layer Diffractive Optical elements.