SENSITIVETHIC PR0HDRTI3S OF DIAZO FIIMS FOR HIGH ACUITY CONTINUOUS TONE 
PHOTOGRAPHIC REPRODUCTION 
This paper will present some of the notable scientific discoveries 
made within the past three years as a result of Air Force sponsored 
research on continuous tone diazo films. The Air Force is constantly 
striving for higher quality photographic reproduction materials. Such 
materials need to have higher image definition, better tone rendition 
through several generations of copies, and be capable of rapid and simple 
printing and processing. The ever growing appetite of the intelligence 
coranunity for large numbers of release copies of long lengths of aerial 
films in the shortest possible time after collection of the photographic 
data, requires that advanced thinking be given to a rapid, high quality, 
simplified method of producing large volumes of release positive copies 
of aerial film negatives. 
Diazo coatings on transparent flexible film base have long been of 
intriguing interest to the Air Force. Diazo films have inherently high 
contrast, high resolution, and produce relatively grainless dye-coupled 
images. The exposing and processing of such films is relatively simple. 
The films are exposed to completion using a very high energy actinic and 
visual blue light source and can be rapidly developed to completion in a 
warm moist chemical vapor in very short periods of time. 
Three years ago, the Air Force established sensitometric objectives 
to support research with conmercial diazo film manufacturers. The 
purpose of this research is to investigate the chemical mechanisms of 
diazo reactions, to study the light physics phenomena associated with 
diazo chemistry absorption and spectral sensitivity, and to study new 
methods of sensitometric evaluation of ultraviolet sensitive diazo films. 
Attainment of the ultimate objective of the preliminary research will lead 
to the formulation of negative and positive working diazo films which have 
high image definition, and have adequate contrast response and adequate 
density scale for the correct tone reproduction of any high or low 
contrast and density scale aerial negatives. Optimized diazo films should 
have good coating uniformity, good dimensional stability, good abrasion 
resistance, useful shelf life, and should produce highly stable images 
when properly exposed, developed, and stabilized. I am happy to state 
that considerable progress has been made within the past three years on 
diazo film research. The possible attainment of many of the original 
goals of this abitious research program now appear on the horizon. 
FIGURE NUMBER 1 - The developed silver granule in the finest grain 
gelatin-silver-halide film is approximately 200 times the size of an azo 
dye molecule which is the image forming structure of diazo film images. 
For this reason diazo films produce high acuity images which are practi 
cally grainless. A typical high acuity gelatin-silver-halide emulsion is 
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AF-WP-O-AUG 6 4 2M