Can anyone confirm that this lens will work properly on the GX7. It looks like when the camera is switched on, it's supposed to extend. My guess is that it's just based on a sensor that either reads "power" or "off" and the lens extends. I just wanted to check before I purchase it. I'd like a more compact solution for a walk around zoom, wife wants to put it in her purse and all that. Also, anyone else here used one or plan to buy one?