6. The elements causing atmospheric haze seem 
confined to a relatively thin layer close 
to the earth, Thus haze has a greater 
effect on the colors seen by the ground 
observer looking through the long demen- 
sion of this thin layer than on colors 
recorded by a camera above and looking 
through the smaller dimension of the 
layer. 
7. Good color photographs (photographs showing 
good color differentiation and near "true" 
representation of ground color), partic- 
ularly of upland areas, can be obtained 
at altitudes above 10,000 feet, 
8, Colors vary in their "strength" as measured 
by their effect on color film. Yellow, 
for example, is a strong color and photo- 
graphs of areas that are predominantly 
yellow are often overexposed, Exposure 
settings should be made with consideration 
of this factor, 
References 
Wheeler, H. E., 1948, Late Precambrian-Cambrian 
stratigraphic cross-section through southern 
Nevada: Univ, of Nevada Bull. Geol, and Mining 
Series No, 47. 
INT.-DUP. SEC., WASH., D.C. 987298