Scene brightness measuring system

Scene brightness measuring apparatus for automatically setting the correct exposure of a camera for photographing a scene, n various parts of which have differing amounts of illumination, comprising a plurality of photosensors arranged in a light-measuring portion of said camera to measure respective brightness values B.sub.i for said n various parts of said scene, where i=1, 2, 3, . . . n;

• detecting circuit means for determining the maximum brightness value B.sub.max from among the measured brightness values B.sub.i and for determining the minimum brightness value B.sub.min from among said measured brightness values B.sub.i ;
• calculating circuit means to which said measured brightness values B.sub.i and said minimum and maximum brightness values B.sub.max and B.sub.min are applied and providing a correct exposure brightness value B determined according to the relationship:
• ##EQU13## where K.sub.1, K.sub.2, K.sub.3, .alpha., and K(i+3) are predetermined weighting factors;
• and exposure operating and control circuit means receiving said correct exposure brightness value B to establish the correct camera exposure for said scene.

Scene brightness measuring apparatus for automatically setting the correct exposure of a camera for photography a scene, n various parts of which have differing amounts of illumination, comprising a plurality of photosensors arranged in a light-measuring portion of said camera, each measuring a respective brightness value B.sub.i for one of said n various parts of said scene, where i=1, 2, 3, . . . n;

• detecting circuit means for detecting the maximum brightness value B.sub.max and the minimum brightness value B.sub.min from among the measured brightness value B.sub.i ;
• means for detecting the mean brightness value B.sub.mean for all said brightness values B.sub.i ;
• calculating circuit means having inputs to receive said maximum, minimum, and mean brightness values B.sub.max, B.sub.min, and B.sub.mean and an output providing a correct-exposure brightness value B calculated according to the following relationship
• B=K.sub.1 +K.sub.2 B.sub.max +K.sub.3 B.sub.min +.alpha.B.sub.mean
• where K.sub.1, K.sub.2, K.sub.3, and .alpha. are predetermined weighting factors;
• and exposure operating and control circuit means receiving said correct-exposure brightness value B to establish the correct exposure for said camera to photograph said scene.

Scene brightness measuring apparatus for automatically setting the correct exposure of a camera for photographing a scene, which scene is divided into N zones, comprising a plurality of photosensors disposed in a light-measuring section of said camera and arranged in groups so that each respective group of said photosensors provides brightness values corresponding to illumination brightness within an associated one of said zones;

• detecting means for detecting the maximum brightness value B.sub.max and the minimum brightness value B.sub.min from among the brightness values sensed by said plurality of said photosensors;
• average value detecting circuit means providing a mean brightness value B.sub.mean (i) for each said zone, where i=1 to N;
• scene brightness calculating circuit means coupled to receive said maximum brightness value B.sub.max, said minimum brightness value B.sub.min, and said mean brightness values B.sub.mean (i), and providing a scene brightness value B according to the relationship ##EQU14## where K.sub.1, K.sub.2, K.sub.3, .alpha., and K(i+3) are predetermined weighting coefficients;
• and exposure operating and control circuit means receiving said scene brightness value B and, in response, establishing the correct exposure for said camera to photograph said scene.