Exposure control method

Abstract

Abstract PURPOSE:To make possible correct exposure for the main subject even for the subjects having the special luminance distribution by performing weighting to the maximum or minimum luminance of each zone of a photometric region and performing exposure controlling by the use of the added luminance. CONSTITUTION:A photometric part 5 having photometric elements 2a-2n on a substrate 1 are constituted by the photometric parts 5a-5d corresponding to the segmented zones Z1-Z4 or Z1'-Z4', and the outputs of the respective photometric elements are logarithmically converted 30, and are then supplied to maximum luminance detecting circuits 31a-31d, by which the maximum luminance Bzi is detected zone by zone. From the output signals of all the photometric elements, the mean luminance of the entire image plane is calculated 32. The subject luminance is calculated 33 by using this mean luminance and zone-by-zone maximum luminances Bzi, and this luminance information is operated 34 by the information from an exposure information setting circuit 35 of film sensitivity, aperture and shutter speed, whereby an exposure control circuit 36 is driven. In this case, the controlling of exposure is accomplished by using the luminances of the formulas I, II weighted and added according to the importance of each zone.

Inventors

• 👤 Takaaki Terashita

Bibliographic Details