I'm looking for something that I can zoom in and out with on my GH2. I'm not super concerned about the focal length, but something in the 35-100ish range would be fine. Perhaps even a 70-200. I won't be using this for full time video, just when I need the effect of zooming in and out. I have a FD adapter, so bonus points if it is a FD mount, though I don't mind getting an adapter for a better zoom. It needs to be at least a 3.5, but the faster the better! I've got a 35-105/3.5-4.5 pull zoom. It works ok, but I'd much rather have a twist zoom. Does anything exist?