Cameras, Continued
Camera
Cameras consist of seven basic components on three parallel planes.
components
Misadjustment of any component part of a process camera affects the
reproduced image in size, clarity, or density. The three parallel planes of a
copy camera are the copy plane, the lens plane, and the focal plane. Consult
the manufacturer’s operating instructions for precise operator adjustments.
COPY PLANE: The copy plane is a glass copyboard that holds the original
copy in place. The most common size is 18 by 24 inches with gridded
reference lines to help align the original copy. Vacuum pressure creates
suction to flatten the copy during a shoot. The copy plane may move on a
track for proportional reductions or enlargements.
LENS PLANE: The lens plane holds the lens in position. Some lens planes
have interchangeable lenses. The lens plane moves along a track for
proportional reductions or enlargements.
FILM or FOCAL PLANE: The film plane holds the film in place in the back
of the camera. The film plane may also have a filter attachment for halftone
or color separation work. Without film, the ground glass of the focal plane
allows for fine focusing an image.
SCALES: Most cameras reduce to 50 percent and enlarge to 300 percent or
a range in between.
FOCUSING CONTROL: Handwheels or cranks rotate to focus an image.
Newer machines have automated push-button focusing.
BELLOWS: Bellows are the accordion folded segment between the lens and
the film plane. Bellows maintain lighttight integrity during enlargements and
reductions.
EXPOSURE CONTROL: Once the copy plane, lens plane, and focal plane
are positioned correctly, the camera scales recommend settings for the f/stops
and/or the shutter speed. Some cameras are set manually and other cameras
are automated. Automated cameras are aperture priority cameras where the
operator sets the shutter speed and the camera sets the aperture opening.
Shutter priority is when the operator sets the shutter speed and the camera
selects the aperture. Little figuring is done by the operator in either case.
Continued on next page
4-33
