Electrical Design Concepts of Exposure Meters with Special Reference to the Ikophot T

Heinz H. Thiele

The Wheatstone Bridge principle can be effectively incorporated in the photo-electrically-actuated exposure controls of 8mm motion-picture cameras as well as in the circuitry of full-range CdS exposure meters. The basic electrical principles of photoelectric brightness measurement are surveyed. Methods of using a Wheat-stone Bridge to measure electrical resistance as a function of subject brightness are explored in terms of various balance indicators. The exact manner in which the Wheatstone Bridge principle has been applied to the circuitry and structure of the Ikophot T exposure meter is described.

Print ISSN
Published
1967-10
Content type
Original Research
DOI
10.5594/J09088