Description of Lens Assembly

The lens assembly includes a lens, a shutter, a lens board, and a
cable release.

a. Lens.
The lens is a four-element 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. Lens assembly mounted in front frame.

b. Shutter.
The shutter has five automatically timed speed settings plus time (T), bulb (B), and seven aperture settings. The shutter also contains an internal synchronization mechanism and a press focus lever to open and close the  shutter to facilitate focusing.

c. Lens board.
The lens board is provided to permit mounting the lens assembly in the front frame of the camera. The front vertical movement plate with the threaded shaft and shaft support, and the front horizontal movement plate with the vertical gear and rack gear shift the lens board and lens to position the image on the ground focusing glass.

d. Cable release.
The cable release is provided for remote operation of the shutter to permit making T, B, or instantaneous (I) exposures without jarring the lens or causing camera movement.