Camera obscura. Prior to the development of the photographic camera, artists would use a camera obscura like the one shown in Figure P24.101 to draw the image of a subject. In this figure, light from a subject passes through a small hole or lens in the box, is reflected from a plane mirror, and is projected onto a translucent sheet of paper. The artist would then trace the image on the paper. Room-sized camera obscura s were also used. Suppose the distance from the pinhole to the mirror is 1.0 m and the mirror-to-screen distance is 50 cm. (a) How far away should a 1.5-m-tall subject stand so that she fills a 25-cm-square screen? (b) Describe how adjusting the size of the pinhole will affect the clarity and brightness of projected image.
Figure P24.101
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