Abstract

Tungsten lamps are now used very extensively in photographic sensitometry, and the wide range of exposures required for various materials makes necessary the accumulation of complete data on lamps of many sizes.

The characteristics of all tungsten incandescent lamps are similar in form, and in this note are described the average characteristics found for twenty lamps frequently used in this work.

From a study of the slope of the straight line, best representing the average candlepower-color temperature relation, it is concluded that the changes in candlepower and color temperature, resulting from a small change in voltage, should be about equally perceptible under good conditions of observation.

© 1939 Optical Society of America

The Operating Characteristics of Incandescent Lamps*

E. W. Beggs
J. Opt. Soc. Am. 29(3) 117-123 (1939)

Changes in Color Temperature of Tungsten-Filament Lamps at Constant Voltage*

Deane B. Judd
J. Opt. Soc. Am. 26(11) 409-420 (1936)

Methods and Instruments for the Determination of Photographic Speeds by Measurement of Relative Characteristic Gradients*

Clifton Tuttle
J. Opt. Soc. Am. 29(7) 267-277 (1939)

The Spectral Emissivity and the Relation of True Temperatures and Brightness Temperatures of Platinum

Robert E. Stephens
J. Opt. Soc. Am. 29(4) 158-161 (1939)

Artificial Daylighting for Color Grading of Agricultural Products*

Dorothy Nickerson
J. Opt. Soc. Am. 29(1) 1-9 (1939)