I guess you didn't see my earlier post. You can meter with "R" lens attached to your F-1, but it will be stopped-down metering, not full aperture metering, like you get with a FD lens. With a battery installed, turn on the camera's meter and set your desired shutter speed. Then turn the secondary aperture ring on your "R" lens (there are two aperture rings) and, as the viewfinder darkens, the meter needle along the right side of the viewfinder will move up or down. When this needle intersects the black index mark, whatever you're photographing has been properly metered and you can now press the shutter button.
Originally Posted by momus
Not the most convenient way of metering, but it does work.