| 摘要 |
A control device, adapted to automatically insert a proper correcting filter in a photographing light path dependent upon the color balance of the film used and the type of lighting conditions, is disclosed. Three signals are developed indicating, respectively, that the illuminating light is sunlight, incandescent light, and fluorescent light. The different types of light are detected by a pair of discriminators, one of which is based upon spectral content and the other of which is based on the presence of flicker. Incandescent light is distinguished from the other types of light by its unique spectral characteristic. Sunlight is distinguished from the other types by the absence of an a.c. flicker in such light. The three signals are applied to a mechanism which inserts the filters. A switching means is provided in-between the latter three signals and the filters so that the set of filters connected to be responsive to the three signals depends upon the color balance of the film used.
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