r the 
on keep- 
y more 
her 
for a num- 
ular or 
d the 
ied to 
are avail- 
le produc- 
of Table 1, 
standard 
hy. At is 
esent state 
ions of 
ASA 
e being 
oriate for 
somewhat 
tion is 
vith small 
y intended 
For 
Ititude 
ar 
case for 
for civil 
L class 
nitial 
seping 
1s are 
jiing in 
d outer 
at 410C 
average 
nid! 
shade 
a number 
Inder con- 
This 
e to the 
TABLE | 
  
Typical Sensitometric Characteristics of Negative Emulsions 
used for Air Photography 
  
  
  
  
  
  
  
  
  
- s Resolving 
Class in Commercial Speci fi- | Approx. > power: lines/ 
M.O.S. Eouivalent cation A.S.A. G mm (0.2 
Specification : Speed Speed contrast) 
N No exact 
equivalent 2.5 300 |. 48 24 
L3 PS 2.3 200 15 27 
L Super XX, H.P.A. 9.2 150 |. 48 26 
À Plus X, f.P.3 1.8 64 |. 74 42 
C Pan F 2 16 1.70 50 
= None - e special 
high resolution 
emulsion 1.0 7 1.70 30 
Test Conditions 
Exposure: I/30th sec., intensity scale. Mean Noon Sunlight with 
Development: 
"Specification Speed" is Minus the 
density of 0.2 plus fog. 
G 
Minus Blue Filter, the latter not taken into account in 
deriving exposure scale. 
10 mins. at 200C agitated. 
is the slope of the line joining the speed-point ( 
a point on the curve of 1.5 log E units greater expos 
logarithm of the exposure giving a 
0.2 plus fog) to 
ure. 
  
TABLE 2 
  
Speed Losses on Storage of Class L3 Film 
  
  
  
  
  
  
Condition of Storage Speed G Fog 
Original Tests 2. 20 L7 0.22 
I2 months normal keeping n 
{circa 20°C) 2,15 KB 0.24 
Accelerated keeping test 2.15 1.04 0.23 
I2 months "dry" tropical 
storage 2.08 1.04 0.19 
I2 months "humid" tropical 
storage 2.08 1.04 0.19 
I8 months "humid" tropical 
storage 2.7 0.95 0.19