Four Thirds lenses on Micro Four Thirds

19.42 mm flange clearance autofocus with caveats

Does a Four Thirds lens fit a Micro Four Thirds body?

Yes, with a simple adapter and no loss of image quality. Four Thirds has a flange focal distance of 38.67 mm and Micro Four Thirds has 19.25 mm, leaving 19.42 mm for the adapter to occupy. Because the adapter contains no glass, the lens performs exactly as it does on its native mount.

Autofocus: Autofocus, with caveats

Four Thirds lenses were designed for phase-detect autofocus. On bodies with on-sensor phase detection — the OM-D E-M1 line and OM-1 — they focus properly. On any other Micro Four Thirds body they hunt badly enough to be unusable for anything moving.

Adapters

• Olympus MMF-3 — Olympus (mechanical, no glass)
• Panasonic DMW-MA1 — Panasonic (mechanical, no glass)

Flange focal distances: Four Thirds 38.67 mm, Micro Four Thirds 19.25 mm.