OLYMPUS Camera and Lens Terminology and Notation Meanings

Zuiko

Lens brand name.
Derived from the word "Zuiko."

OM

System name for 35mm film SLR cameras.
Camera bodies and lenses for this system have "OM" in their model numbers.
Initially, it was "M," but due to a complaint from Leica, it was renamed to OM.

PEN (Film Camera)

Series of half-frame compact film cameras.
PEN F is a half-frame SLR camera.

Four Thirds / 4/3

Common standard for digital SLR cameras.
Proposed by Olympus and Kodak.
Mainly refers to sensor size and mount.

Micro Four Thirds

An extension of the Four Thirds standard, designed for mirrorless cameras. Developed by Olympus and Panasonic.
Because the mount shape and flange focal distance are different, Four Thirds lenses cannot be shared directly with Micro Four Thirds. However, Four Thirds lenses can be used on Micro Four Thirds cameras with a mount adapter. The reverse is not possible.

E Series

Series of digital SLR cameras using the Four Thirds system.

PEN (Digital Camera)

Mirrorless interchangeable lens camera using the Micro Four Thirds system.
Positioned as the digital version of the PEN film camera series, but lenses and other accessories are not interchangeable.
Features a compact and lightweight design.

OM-D

Mirrorless interchangeable lens camera using the Micro Four Thirds system.
Positioned as the digital version of the OM film camera series, but lenses and other accessories are not interchangeable.
Features an SLR-like style with an electronic viewfinder positioned on the optical axis.

ZUIKO DIGITAL

Four Thirds mount lenses

M.ZUIKO DIGITAL

Micro Four Thirds lenses

IS

Abbreviation for Image Stabilization.
Refers to the image stabilization function.

PRO

Lenses with professional-grade optical performance and dustproof/splashproof specifications.

ED

Lenses using Extraordinary low Dispersion glass.

SWD

Abbreviation for Supersonic Wave Drive
Refers to an ultrasonic motor.

EZ

Power zoom

II

Second generation of the same specifications

R

Exterior change