| 摘要 |
PURPOSE:To realize the measurement of exposure in accordance with a desired subject and with no effect given from the background having the excessive light intensity, by extracting only the output having the difference of output higher than a prescribed level between the adjacent photodetectors and then processing the extracted output. CONSTITUTION:Outputs Pi and Pj of adjacent photodetectors Di and Dj of a light receiver 6 are stored in registers 15 and 16, and the difference between these outputs is delivered through a subtractor 17 to be compared with the reference value delta0. Then the count signal is delivered and processed only when the difference of outputs is larger than the value delta0. In such way, only the outputs Pi and Pj larger than the value delta0 of all photodetectors are added together through an adder 23 and by a scan, and then divided by the count number through a divider 24. This output is led to an exposure arithmetic circuit 25 in the form of the photometric value of subject. Thus the exposure value is calculated. In such way, only the output of contrast higher than the value delta0 receives the photometry. Accordingly, the pure white sky or a deep-black area is cut to obtain the exposure value according to the brightness of the subject. |
