hybrid systems such as electronic air-to-air and air-to-ground 
range measurements and astro or solar camera orientations with 
any desired relative weight in the aerotriangulation adjustment. 
The principal instruments and items of equipment in our 
present photogrammetric system include: 
Aerial Photography 
Wild RC-7A, wide-angle, automatic plate camera, 
F=100mm (4 inches). 
Wild RC-8, wide-angle film cameras with Aviogon and 
Infragon cones, F=153 mm (6 inches). One Aviogon cone 
has 4 extra side fiducial marks for measurements that pro 
vide for more accurate compensation of film distortion. 
A Wild Universal Aviogon film camera is on order for 
delivery in about 6 months; this camera will also have a 
total of 8 fiducial marks. 
Wild RC-9 super wide-angle film camera, F=88.5 mm 
(3.5 inches). 
Laboratory Photography 
An air photographic laboratory equipped to process 
film and to make all types of prints required for metric 
photogrammetry including the processing and printing of 
color photography. This laboratory contains the following 
principal items of equipment for color photography: 
Zeiss wind-rewind equipment (FE-120 film developing 
outfit) for film processing with a special red brass tank 
for the bleaching solution. 
Color print processing equipment using a nitrogen burst 
system for the production of opaque type reversal 
prints. This equipment was made by the Rolor Manu 
facturing Company to Coast and Geodetic Survey 
specifications. 
LogEtronics contact printer - with a full color spectrum 
cathode ray tube and an automatic dodging circuitry 
equipped with a special vacuum platten designed to 
give good contact when printing either on glass or paper. 
Special processing tanks for handling baskets of 13 color 
glass plate diapositives simultaneously (figures 20 and 
21). 
Aerotriangulation-Plotting Instruments 
1 Zeiss Stereoplanigraph C-8 
1 Zeiss Stereoplanigraph C-5 
1 Wild Autograph A-5 
Analytic Aerotriangulation and 
Satellite Triangulation 
2 Mann Monocular Comparators, Model 422F, with a bi 
nocular zoom-type direct viewing system providing a range 
of from 20 to 60 power magnification. 
A Wild STK-1 Stereocomparator with optical switches 
providing a range of from 6 to 40 power magnification. 
Use of the following electronic computers: 
IBM 650 
IBM 1401 
IBM 1620 
IBM 7030 (STRETCH) 
Map Compilation and Single Model 
Measurements 
Wild B-8 plotters 
Kelsh plotters. 
COLOR PHOTOGRAPHY 
Our day-to-day, routine use of color photography represents 
a relatively new and vastly important improvement in our 
photogrammetric system. I am convinced that the use of color 
for metric photogrammetry is going to be extremely important 
to most of you and I shall now endeavor to describe the tech 
niques and present state of color photogrammetry in some detail. 
The merit of color photography lies in its interpretability. 
It is easier to read. The General Aniline and Film Corporation 
and the Eastman Kodak Company in the United States have 
made great progress in the production of color aerial film in recent 
years, I might almost say in recent months. Color film available 
today is as fast and has as high a resolution as the Plus X 
panchromatic, or other panchromatic emulsions, normally used 
for metric photogrammetry. It has the great additional advantage 
that all color gradations in nature are reproduced in varying 
shades of color on the photographs—whereas all panchromatic 
films reduce these shades of color to shades of gray. One can see 
more on color. Color photography records thousands of separable 
colors, shades, and hues, whereas panchromatic photography 
records only about 200 distinguishable shades of gray. This is 
the simple and specific reason that color is vastly superior 
in interpretability to any black and white photographic film 
usable in wide-angle cameras. The interpretative quality of color 
photography is well illustrated in Figures 7 to 16, but no printing 
press reproduction can ever equal the quality of the original 
photograph or photographic prints made from the original. 
Further, you will never fully appreciate the possibilities of color 
photography until you have viewed a pair of color plates under 
a good stereoscope or in an optical viewing plotting instrument. 
The following instruments and items of material are neces 
sary for the utilization of color aerial photography for mapping 
or other phases of metric photogrammetry: 
Precision aerial cameras with the highest quality lenses 
having relative apertures of f5.6 or larger. 
Precision optical filters for eliminating ultraviolet light 
which is dispersed by the atmosphere. 
Color films of high speed and high resolution on stable base 
film. 
Color duplicating emulsions on glass plates. 
A color laboratory equipped to process the color film and to 
make prints on glass plates as a minimum. Facilities for 
making opaque reversal type prints are also desirable. 
Optical viewing plotting instruments for both aerotriangu 
lation and for map delineation. 
All of the above facilities are available today and it is for 
this reason that I made my previous statement that color aerial 
photography is now ready for application to metric photo 
grammetry. The long-range economy to be realized by installing 
color processing in any given mapping organization will depend, 
of course, on the job to be done. But I have no doubt that such 
installations will soon be made in all organizations concerned 
with topographic mapping and resource evaluation. With these 
preliminaries, I think we should now look into the details 
of taking, processing, and using color aerial photography. I shall 
do this by starting with the aerial photography and going through 
the matter item by item to the stereoscopic instrument delinea 
tion of details. 
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