Exposure System; Exposure Sequence; Exposure System Components - Polaroid 8035 Repair Manual

8K Series ProPalette Repair Manual Theory of Operation

Exposure System

Exposure Sequence

ProPalette uses the latent memory of photographic film to record light and to blend the
shapes and colors from a sequence of colored exposures. The exposures are made from
black-and-white, computer-generated video scan lines.
Upon command from the host computer, ProPalette creates a black-and-white video scan
line for a specified amount of time on the CRT. When projected onto film through lenses
and colored filters, a series of these scan lines creates a full-color image on the film. This
sequential exposure technique combines exposures of each primary color to produce
almost any shade or hue.

Exposure System Components

Figure 3-2 shows a simplified representation of the ProPalette exposure system. It
consists of a camera back/adapter assembly, a filter wheel assembly, a filter wheel photo-
interrupter that provides wheel position information, an autoluminance photodiode
assembly to sense CRT brightness, and the CRT assembly.
Figure 3-2. ProPalette exposure system
Camera Back/Adapter Assembly
Several camera back assemblies are available for use with various ProPalette models.
Each camera back includes a fixed-focus, fixed-aperture lens. (ProPalette controls
exposure via the intensity and duration of the CRT scan lines.)
Filter Wheel Assembly
The filter wheel assembly positions the appropriate colored filter (red, green or blue)
between the CRT and the film. Filter movement is initiated by the host computer, which
issues a command to ProPalette to rotate the filter wheel until the appropriate filter is in
position.
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