Sorry if this has been asked already, but I'm new to the world of M4/3 cameras. I have just bought the OMD EM10 kit with 14-42mm, the old manual zoom and not the new pancake power zoom. I tried it out in store and preferred the manual handling. However, I've just tried it at home and it makes a strange whirring noise which I didn't expect, or hear in store although in store was obviously a much noisier environment. When you focus, either AF or manual it makes a constant whirring noise until you release the shutter button, or focus ring. Even after it's focussed and you're holding focus lock it will whirr forever until you release the shutter. Is this normal? Seems odd, and a little annoying Any help appreciated.