I was out shooting with my OM-D and the Olympus 40-150mm lens yesterday. I went to take a shot and the viewfinder went black - like I had the lens cap still on. You could see all of the camera settings - but no image. I turned the camera off and back on, and it cleared up. I made several pictures ok, and then it happened again. I discovered that as I zoom out, at a certain point if goes black. Then you have to turn the camera off to get it working again. I changed to my 12-50mm lens, and it seems to work OK. Thought I would see if anyone had seen anything like this before I call Olympus.