Polaroid ProCam Repair Manual page 17

Essentially, the ProCam system relies on the optical results of changing its Quintic
aspheric lenses. Because of the way the aspheric lenses are shaped, the system can
create ten (10) different zones.
The characteristics of the Quintic system are such that it has a greater focal length
than lens systems in previous Polaroid cameras. This results in larger subject
images being produced.
Figure 1-8 shows the components of the ProCam Quintic lens system. It is a six
element, 95mm lens system. The front assembly contains two fixed lenses, one
spheric and one aspheric. The rear assembly contains three fixed lenses, one
spheric and two aspheric. The middle element, called the Quintic sector, pivots in
an arc through the optical path of light leaving the front lens assembly. It is this
movement of the Quintic sector that results in the actual focusing function.
ENCODER CIRCUIT
PHOTOTRANSISTOR
Figure 1-8. Components of ProCam Quintic Lens System
Refer to Figures 1-9 through 1-12 when reading the following description of
Quintic lens operation. Also, refer to the sequence of operation portion of this
section for a more detailed description of the sequence of events which move the
camera lenses into proper focus.
REAR LENS
ASSEMBLY
1 - 11
MOVING
QUINTIC LENS
FRONT LENS
ASSEMBLY
LED