The design and construction of an exposure meter for use with infrared sensitized film

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dc.contributor.advisor Rubin, Jacob Fitz, James A. 2009-01-14T23:31:47Z 2009-01-14T23:31:47Z 1980-05
dc.description.abstract In this project, an exposure meter which is sensitive to, and calibrated for infrared radiation was designed and constructed. An EG&G SGD-100A silicon photodiode was chosen to use as the photodetector. This choice was based on cost, availability, ruggedness, stability, and sensitivity. A circuit using an operational amplifier to amplify the output of the photodetector was used. The circuit design allowed easy variation of the signal gain to give a detectable meter deflection under varying lighting conditions. Five different gains were used to allow use of the meter under conditions ranging from outside under direct sunlight, to inside with typical room lighting. The gains used were empirically established. The film used was Kodak HIE 135-20. This is a black-and-white panchromatic emulsion with special sensitizing agents added to extend the film's sensitivity into the near infrared to about 900 nanometers. The spectral response of the photodetector was to be filtered to match the spectral response of this infrared sensitized film. This proved not to be possible, due to the unavailability of any regular, stock filter which cuts off wavelengths above 900 nanometers. Despite this problem, the meter is much more accurate for setting exposures for the infrared sensitized film used than a normal exposure meter. The designed meter typically indicates within one stop of the optimum exposure for this film. A normal exposure meter reading made using Kodak's exposure recommendations was incorrect by as much as three stops. en_US
dc.language.iso en_US en_US
dc.relation RIT Scholars content from RIT Digital Media Library has moved from to RIT Scholar Works, please update your feeds & links!
dc.subject Calibration of meter en_US
dc.subject Circuit design en_US
dc.subject Gray scale inconsistencies en_US
dc.subject Photodetector en_US
dc.subject.lcc TR196 .F57
dc.subject.lcsh Photography--Equipment and supplies--Design and construction en_US
dc.title The design and construction of an exposure meter for use with infrared sensitized film en_US
dc.type Thesis en_US College of Graphic Arts and Photography en_US
dc.description.department School of Photographic Arts and Sciences en_US

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