Exposure control circuit for camera - includes variable resistor to adjust for under-exposure or over-exposure

摘要

Besides the photocell (2) and battery (3), the circuit includes balancing resistor (4) and a measurer (1) - meter, aperture adjuster, or the like. A variable resistor (5) is connected in parallel with the balancing resistor (4) and measurer (1), and tones a middle value (5b) for normal exposures. The variable resistor takes a greater value (5a) for over-exposures and a lesser value (5c) for under-exposures. - Instead of a variable resistor fixed resistors may be used, either being switched into the circuit or short-circuited by switches.