The illuminated image of the picture area on the film is reflected via several mirrors to the screen. The screen is
actually a large magnifying glass held at the correct distance by the metal "hood". This "hood" is stored inside the
body of the muray viewer when ont in use. The "hood" is hinged at the front, so lifting the back edge swings the screen
up and round at the same time. A button springs out and latches the "hood" in the correct position. To put the "hood
back into the horizontal position, push button in an hold until hood is clear of the button hole.