| 摘要 |
PROBLEM TO BE SOLVED: To provide a dimming method and a dimmer for performing automatic dimming even for a photographic object having a large reflectance. SOLUTION: The dimmer controls the light quantity of an illumination so that the luminance level of an image becomes a predetermined value, wherein an illumination light shielding plate is used such that the total light quantity of a lamp is passed when the shielding plate is fully opened and the total light quantity of the lamp is shielded when the shielding plate is totally closed. The shielding plate is also used to limit the shielding amount on the basis of the light spreading characteristic of the lamp in an intermediate opening position, and the light quantity of the light passing through the shielding plate varies in a logarithmic curve according to the movement of the shielding plate. With the logarithmic curve variation, the moved amounts of the shielding plate for doubling or halving the passing light quantity at an arbitrary position of the shielding plate are made to be equal to each other, thereby making the control easy. COPYRIGHT: (C)2010,JPO&INPIT
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