The short focal lenght comparison.

Raymond sent me an interesting link:

“micro four thirds has the shortest flange focal distance of any photographic camera currently
available.
The mounts with smaller registers are D for 8mm, CS, C mounts for 16mm
movie cameras or cctvs and the Canon EX a camcorder which equals the
M4/3s register.

Check it out: http://www.markerink.org/WJM/HTML/mounts.htm “