sentences:  The Micro Four Thirds lens mount is a slightly modified version of the standard Four Thirds mount, and a number of lenses have been built for it.Because the lack of a mirror, optical viewfinder, and a shorter flange-focal distance these lenses can be more compact than those for standard Four Thirds.Standard Four Thirds lenses can be used on a Micro Four Thirds camera with full electronic communication using an adapter, but those that do not support contrast-detect autofocus will only autofocus slowly, if at all.