The Four Thirds system is a standard created by Olympus and Kodak in 2001 for digital single-lens reflex camera (DSLR) design and development. Unlike older SLR systems, Four Thirds has been designed from the ground up to be entirely digital.
The Micro Four Thirds system was developed in 2008 by Olympus and Panasonic.
The Four Thirds System standard offers the benefits of compact, lightweight performance, and the new Micro Four Thirds System standard takes this still further to enable development of new ultra-compact interchangeable lens type digital camera systems.
The image sensor diagonal dimensions are the same for both Four Thirds System and Micro Four Thirds System standards.
The Micro Four Thirds System standard enables users to enjoy the same high image quality of the Four Thirds System’s 4/3-type image sensor in a much more compact body, and also take advantage of significantly more compact lenses, particularly in the wide-angle and high-power zoom range.
The new Micro Four Thirds System standard also incorporates a greater number of lens-mount electrical contacts (increased from 9 to 11) for the support of new features and expanded system functionality in the future.
Other primary distinguishing features of the Micro Four Thirds System standard (when compared to the Four Thirds System standard) are:
Approximately 50% shorter flangeback distance (mount-to-sensor distance).
Lens mount outer diameter approximately 6mm smaller.
