PURPOSE: To perform high-precision direct photometry operation by arranging a fixed translucent mirror behind a movable reflecting mirror, and setting the reflectance of the translucent mirror properly and controlling the quantity of photometry optionally.
CONSTITUTION: A reflecting mirror 2 moves away from an optical path of photography during photography; part of luminous flux from a body which is passed through a photographic lens 1 is reflected by the translucent mirror 14 and measured by the photodetection system which has a photodetection lens 15 and a photodetecting element 16, and the remaining luminous flux forms an image on an image pickup surface 6. The quantity of photometry is controlled optionally by setting the reflectance of this translucent mirror 14 properly to perform a high-precision measurement of light. For the purpose, a mirror which reflects infrared light principally and transmits visible light is used as, for example, the translucent mirror 14 and the photodetecting element 16 is made sensitive to infrared light to increase the quantity of photographic light image- formed on the image pickup surface 6; and an infrared-light cutting filter 3 in front of an image pickup body is omitted and the device is simplified.
KATOU MASATAKE
NISHIMURA TETSUJI
