However, you should note that not all FT lenses will autofocus on Panasonic MFT cameras. Only fairly recent lens designs that are prepared for contrast detection auto focus (CDAF), will work. The compatible FT lenses are
- Olympus Zuiko 25mm f/2.8 Pancake
- Olympus Zuiko 9-18mm f/4-5.6
- Olympus Zuiko 14-54mm f/2.8-3.5 II
- Olympus Zuiko 14-42mm f/3.5-5.6
- Olympus Zuiko 40-150mm f/4-5.6
- Olympus Zuiko 70-300mm f/4-5.6
- Panasonic Leica D Summilux 25mm f/1.4 Asph
- Panasonic Leica D Vario-Elmar 14-50mm f/3.8-5.6 Asph Mega O.I.S.
- Panasonic Leica D Vario-Elmar 14-150mm f/3.5-5.6 Asph Mega O.I.S.
These lenses will autofocus on Panasonic Lumix MFT cameras, like G1, GH1 and GF1.
Newer Panasonic cameras like GH2, G2 and G10 feature some improved autofocus functionality using some FT lenses. For example, the GH2 can autofocus using the Olympus 50mm Four Thirds lens, but the focus is very slow. The Panasonic G1, GH1 and GF1 will not autofocus this lens at all.
All Olympus MFT cameras can autofocus with all FT lenses, so Olympus camera users can ignore this list. This also goes for Panasonic FT lenses used on Olympus MFT cameras. The autofocus can be very slow with some FT lenses, though.
For those combinations of lenses and cameras where autofocus works, you will still experience slow autofocus with FT lenses on both Panasonic and Olympus MFT cameras. I have made a comparison of autofocus speeds using some MFT and FT lenses on the Panasonic GH1. Also, a similar comparison for the Panasonic GH2.
Even if autofocus does not work on some camera/lens combinations, other functions like aperture control will still work. And using manual focus is not that difficult. Here is an illustration of using manual focus with Olympus 50mm f/2 macro on Panasonic Lumix GH1.