6 
NORMAL pH LEVELS AND RECOMMENDED 
TOLERANCES FOR ANSCHROME PROCESSING 
SOLUTIONS—R—l PROCESS 
Solution 
Normal 
Fresh pH 
U seful 
pH Range 
First Developer 
10.20 
10.15 to 10.25 
First Developer 
Replenisher 
10.25 
10.20 to 10.30 
Short Stop Hardener 
4.50 
4.40 to 4.60 
Short Stop Hardener 
Replenisher 
4.10 
4.00 to 4.20 
Color Developer 
10.60 
10.55 to 10.65 
Color Developer 
Replenisher 
10.75 
10.70 to 10.80 
Bleach 
5.20 
5.10 to 5.30 
Bleach Replensiher 
5.20 
5.10 to 5.30 
Fixer 
9.50 
9.40 to 9.60 
Fixer Replenisher 
9.50 
9.40 to 9.60 
Stabilizer 
6.90 
6.60 to 7.20 
Final Rinse 
7.00 
6.90 to 7.10 
TABLE 4 
pH LEVELS USED BY COAST AND 
GEODETIC SURVEY FOR PROCESSING 
EASTMAN MS EKTACHROME FILM 
Normal pH Useful pH 
Range 
First Developer 
10.0 
9.5 to 10.5 
Hardener 
3.0 
2.8 to 3.2 
Color Developer 
11.4 
10.9 to 11.9 
Clearing Bath 
4.5 
4.2 to 4.8 
Bleach 
7.5 
7.0 to 8.0 
Fixing Bath 
4.5 
4.2 to 4.8 
Stabilizer 
6.3 
5.8 to 6.8 
TABLE 5 
Reflective Type Color Prints: Reflective type prints are 
not essential for aerotriangulation and stereoscopic compilation 
with color photography but they are very useful during these 
phases for marking pass points and we find them very valuable 
for field work, that is, for control identification and for anno 
tation of special features. Consequently, we installed equipment 
for producing contact scale color reflective prints and the system 
is now working quite well. Actually, the routine production of 
good quality reflective type prints has been one of the most 
difficult phases of our development of color processing. This has 
been due in part to the need for working out adequate quality 
controls and procedures and also to the fact that the available 
materials have not, until recently, been entirely adequate for 
reproduction of aerial photographs. 
We are making these prints on Ansco Printon material. 
This is a reversal material possessing the high resolution needed 
for aerial photography. The General Aniline and Film Corpor 
ation have greatly improved this material over the last few years 
and today it is far superior to what we started with just a short 
time ago. In our laboratory, which is relatively small, one man 
can now produce about 100 good quality reflective type contact 
scale color prints per day compared to a production of about 
250 black and white prints. The Eastman Kodak Company has 
recently furnished us with a special Kodak Ektachrome paper 
that we are now testing. 
We use a LogEtronic contact printer having a full-spectrum 
cathode ray tube for exposure. Proper exposure and color bal 
ance are obtained by using the rigid full-spectrum light source 
and a cone-shaped hood to cover a 9 x 9 inch transparent format. 
A MacBeth Quanta-Log color analyzer is incorporated in this 
system. The integrating system avoids the need for multiple 
densitometer measurements to control color balance and ex 
posure time. Only a few seconds are required to make the 
readings necessary to control exposure. The prints are processed 
in a Rolor processing unit built to handle the full size 9x9 inch 
aerial prints. Processing is done at 75° F. using Anscochrome 
80° chemistry. This simplifies the water temperature control 
problem since all the laboratory operations can be performed at 
this single temperature. Sensitometric strips are processed along 
with each Printon run. The pH readings are taken prior to the 
start of processing. 
Color enlargements are desirable for some of our field work 
but we are not yet equipped to make these on a production 
basis. We have equipped our existing Salzman enlarger with a 
full-spectrum light source to make occasional enlargements; 
eventually, we intend to obtain a new enlarger witn a high in 
tensity full-spectrum light. 
I might add that we have made up to 20 diameter enlarge 
ments, the limit of our present enlarger, from photographs 
taken with the new color films without a granular breakdown. 
I mention this because some have questioned the practical 
degree of enlargement from color aerial transparent films. 
Color Diapositive Plates: The Eastman Kodak Company 
forged the last link in the chain of color photography for metric 
photogrammetry when they furnished us with experimental 
color plates in the fall of 1963. These plates are now in pro 
duction and available for purchase. We have used them contin 
uously for about a year and have found no reason to regret our 
original enthusiasm. The plates are made by laminating Kodak 
color duplicating film on l A inch glass. The color balance, 
contrast, granularity, and resolution are all excellent and metric 
stability is equal to that of the black and white emulsions or 
dinarily used for aerotriangulation. For testing plates, we print 
a master grid onto the plate in the vacuum printer with a point 
light source and then measure this grid on a comparator. The 
standard error on a single grid intersection coordinate on the 
color plates after a least squares fit for correspondence was less 
than 2 microns (1/12,000 inch). 
The printing and processing of the plates are handled in 
the same manner as Kodak color duplicating film of this same 
emulsion. The plates are exposed in the LogEtronic printer 
with the automatic dodging feature at the maximum setting. 
Exposure times on the printer have ranged from 15 to 30 
seconds. 
The plates are processed in special baskets, as shown in 
figure 20, using a nitrogen burst system. The use of the nitrogen 
burst system assures even processing and density throughout 
the run and our arrangement has a capability of 39 plates per 
run using three baskets. 
The plates are processed with standard Kodak E-2 and E-3 
chemistry as shown in Table 6. In our laboratory we can handle 
two processing runs per day, one in the morning and one in the 
afternoon, with a total production of 78 plates with two men 
operating the system, one printing and one processing.