| 摘要 |
The exposure meter is used in mirror reflex cameras wherein an image of an object projected by a picture taking lens onto an image plane is observed by means of a pentaprism through an ocular. For the purpose of the selective integral or spot exposure metering, a pentaprism (6) is provided at the lower edge of its exit surface with a partly transmitting concave mirror (16). The angles of the pentaprism (6) are selected so that a portion of the light flux leaving the exit pupil (EP) of the picture-taking lens (2) is incident on this concave mirror (16). A first photoelectric detector system is associated with the concave mirror (16) and a second detector system is associated with the prism surface (6c) following the concave mirror in the direction of the beam path, and the output signals from these detectors control a display and/or an exposure control. An additional optical component (13,14a,15b,15) is provided to implement a desired beam path in the pentaprism (6).
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