Description of Lens Assembly (figure 4)
The lens assembly includes a lens, a shutter, a lens board, and a
a. Lens. The lens is a fourelement anastigmatic type XII copying
unit. It has a focal length of 12 inches and a maximum aperture of f/6.3.
The lens elements are coated to reduce internal reflections.
FIGURE 4. Lens assembly mounted in front frame.