Designed from the ground up as a true hybrid still/motion lens, the kit zoom on the GH1 has an impressive range, optical stabilization, smooth autofocus, stepless aperture, and near-silent operation.
Sadly, the trade-off is that the GH1’s kit lens is slow as molasses, with a maximum aperture of f/4.0 at the wide and and a pinhole f/5.8 at the long end. If the GH1’s 4/3 sensor is the key to shallow depth-of-field, the kit zoom is a big wad of stale gum shoved in the keyhole.
Sure, there are some faster lenses for the GH1. Like this 24mm f/1.4 from Panasonic. For a mere $1100 you can have a fast prime that eliminates many of the above advantages of the GH1’s video mode.
Yes, more and cheaper Micro Four Thirds lenses are on the way, and one hopes that many will offer the video features now exclusive to the MolassoFlex 14–140mm. But in the meantime, folks are going crazy creating adaptors for the GH1.