| 摘要 |
<p>PURPOSE:To improve the averaging of exposure values with a photometric device by providing an intermediate reflecting surface at an angle of inclination differing from that of other reflecting surfaces and so constituting the other reflecting surfaces that the distances from the rotating axial center of a rotating blade change. CONSTITUTION:The 1st and 2nd reflecting surfaces 15, 16 respectively form part of nearly a circular cone shape and an intermediate reflecting surface 17 has an angle of inclination differing from that of other reflecting surfaces 15, 16. Hence, when the photographing is stopped and a blade 8 is stopped in the position where it shuts off the passage of incident rays, the intermediate reflecting surface 17 sends the incident rays L to an exposure device 7 at all times, thus the quantity thereof becomes equal to the mean quantity of light entering the exposure device during the rotation of the blade 8. In addition, the 1st and 2nd reflecting surfaces 15, 16 are so formed respectively that the side near the intermediate reflecting surface 17 goes closer to the rotating center of the blade 8 and the side further therefrom goes apart therefrom. Hence, the photometry of various portions of the subject may be performed and the more averaged exposure value may be obtained.</p> |
