3 
I 
direct positive copy is obtained* This illustrated low contrast black 
diazo film has a gamma of 0*95 with a density scale of 1.60. It requires 
2*213 watt seconds per square centimeter of exposure to blue or U.V. 
light for complete exposure or burn-out. 
FIGURE NUMBER 6 - SPECTRAL SENSITIVITY - LOW CONTRAST BLACK DIAZO 
FI IK 
Considerable insight has been gained concerning the spectral response 
of diazo films to both line and continuous emission ultraviolet and 
visual blue light sources. A large portion of the latent spectral 
sensitivity of diazo films is presently being lost by exposing these 
films to line emission mercury vapor light sources. This Figure 6 shows 
the spectral sensitivity of a typical low contrast black image diazo 
film to be from 3500 to 4400 Angstroms with peak sensitivity at 3950 
Angstroms. 
FIGURE NUMBER 7 - SENSITQMETRIC CURVE - MEDIUM CONTRAST DIAZO FILM 
This figure shows the sensitometrie curve for a medium contrast 
black image diazo film. The ganma of this film is 1.20 and the density 
scale is 1.73. This film requires O.965 watt-seconds per square centi 
meter of U.V. or visual blue light for complete exposure or burn-out* 
FIGURE NUMBER 8 - SPECTRAL SENSITIVITY - MEDIUM CONTRAST DIAZO 
FIIM 
This figure shows the spectral sensitivity of the medium contrast 
black image diazo film. This film is sensitive to light from 3400 to 
4400 Angstroms with sensitivity peak at 395° Angstroms. 
FIGURE NUMBER 9 - SENSITQMETRIC CURVE - HIGH CONTRAST DIAZO FIIM 
This figure showw the sensitometric curve for a high contrast black 
image diazo film. The gamma of this film is 2.04 and the density scale 
is 1*94* This film requires 0.655 watt-second per square centimeter of 
U.V. or visual blue light for complete exposure or burn-out. Note that 
the lower the gamma response of the diazo film, the more U.V. or blue 
light energy that is required for exposure. This is due to the use of 
a U.V. absorber in the lower contrast diazo films to control contrast 
response and burn-out rate of the diazo. 
FIGURE NUMBER 10 - SPECTRAL SENSITIVITY - HIGH CONTRAST DIAZO FIIM 
This figure shows the spectral sensitivity of the high contrast 
black image diazo film. This film is sensitive to light frem 3400 to 
4300 Angstroms with peak sensitivity at 3890 Angstroms.