Emulsion Sensitivity for the Photography of Cathode-Ray Tubes

The factors which are significant in the photography of cathode-ray oscilloscope traces were studied with a photometer built especially for this purpose and by means of photographic tests. The photometric tests made with the special photometer showed that the initial decay of the P-11 phosphor is a logarithmic function of time and that recurrent traces on the same area of the screen do not all produce the same intensity of phosphorescence. For such multiple tracing, the intensity of phosphorescence was found to increase progressively for the first several traces; and, in some cases, the intensity of phosphorescence was found to decrease after the initial increase. Photographic tests made on four films with an oscilloscope camera, used in conjunction with the oscilloscope photometer, and with two sensitometers showed that the relative sensitivities of the films for oscilloscope photography can be evaluated fairly reliably by a sensitometric test when the sensitometer light source is filtered to produce a spectral energy distribution equal to the spectral energy distribution of the phosphorescent screen and if the exposure time is 250 μsec or less.

Print ISSN

0361-4573

Published

1959-04

Content type

Original Research

DOI

10.5594/J11056