Quote Originally Posted by BMbikerider View Post
I don't think it has been mentioned but did try this with a film loaded. It will not function as we expect it to without one.
This is true of some cameras.
My Pentax LX reads light off the shutter curtain on short exposures and off the film on long exposures, and holds the shutter open until it has collected enough light for a proper exposure. If there is no film in the camera, it will read off the black pressure plate and will take much longer. But the F3 only meters OTF for flash.