PURPOSE: To use principal rays to locate a real image produced by a convex lens.
DESCRIPTION: The central ray passing through a half-silvered mirror serves as the optic axis, and the vertical ray between the two mirrors serves as the object arrow. By rotating the mirror at the tip of the arrow the three principal rays (or other rays) can be produced, all of which intersect at the image. The focal points of the lens, about 17" (43cm) from the lens surface, can be indicated using squares of masking tape or black tape. A single converging lens in front of the object is used to keep the ray narrow. The object must be close to the left side of the optical board to keep the image on the board.
REFERENCES: (PIRA unknown.)
EQUIPMENT: Optical board with double mirror "object" and hyperbolic lens, spherical lens to keep ray narrow.
SETUP TIME: None.
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