Purpose:Determine the image position for an object in front of a convex mirror using the three principal rays.
Description:This is a very short focal length circular mirror which will form a virtual image inside the mirror. The tip of the object arrow is a rotating front surface mirror; the optic axis is located by light passing through the center of a half-silvered mirror, part of which is reflected by the mirror at the tip of the object. The three principal rays can be formed by rotating the mirror, and their projection within the convex mirror marked by masking tape. Use of other rays verifies that all rays from the source point converge on the image point. The convex lens before the mirror setup keeps the rays narrow.