Polaroid Joshua Vision Service Manual page 20

The image path through the single-lens reflex viewfinder, from the scene to the camera user's eye, is shown
in Figure 1-13. From the taking lens, the image is directed onto a fixed viewing mirror at 45 degrees . . .
then to a textured fresnel focusing screen . . . back to the viewing mirror . . . and then to a concave
mirror, which directs the image of the object through an eyelens to the user's eye. The visual framing field
equals the photographic field at all distances.
Figure 1-13. Image Path through Single-Lens Reflex Viewfinder
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