Was unclear what lens functions are retained.
In short, all! So also the autofocusing.
I tested the functionality with the following Olympus Zuiko Digital lenses:
18 -180mm 1: 3.5-6.3
12 - 60mm 1: 2.8 to 4
8mm 1: 3.5
50mm 1: 2 (macro)
70-300mm 1: 4.5-5.6
Conclusion:
The contrast autofocus of GF2 comes with the 70-300mm lens cope best. It works quickly and accurately, that it is a pleasure.
The other lenses take time for focusing. She drives jerkily back and forth, until the focus is found. These lenses are therefore really only a stopgap. But that's okay because the purpose of buying the GF2 was indeed the handiness.
