The diapositive plates are dodged during printing opera- 
tions and developed to a density range from 0.25 to about 1.2. 
The contrast desired depends upon the nature of the terrain and 
image content. .In general, the diapositives should be prepared 
to the contrast desired in the orthophoto output. It has been 
noted that increasing the "snap" or contrast of an output beyond 
a certain point is accomplished at the expense of losing fine 
detail in areas where slight tonal variations are important. 
65. General Operational Procedures - The steps in compiling 
with the UNAMACE are listed in sequence as follows: 
a. Four pre-loaded plate holders, two containing the 
input glass plate diapositives and two containing unexposed film, 
are placed in their respective previously designated scanning 
tables, The holders drop into place without any shifting or 
alignment. The selector switch on the console is then set 
appropriately designating the function of each of the four tables, 
namely, diapositive one, diapositive two, orthophoto printer or 
contour printer. The entire procedure takes approximately one 
minute. 
b. The operating program tape is then input to the 
computer and the UNAMACE tables are directed to their desired 
"zero" operating position. This program contains operating 
procedures and specific sequences for the use of all data, 
constants and parameters that will be entered later. This 
operation takes less than one minute. 
c. The input data tapes, prepared from the data forms, 
are now entered into the UNAMACE computer. Additional coordinate 
data are entered directly into the computer from manually controlled 
counters. The tapes contain all the data required to characterize 
the specific photography being used. This operation takes less 
than one minute. 
d. The scanning tables carrying diapositives No. 1 and 
No. 2 automatically move to the vicinity of the first fiducial mark. 
The operator, using manual control while viewing the fiducial 
mark in the stereoviewer, centers the mark precisely under a 
reference mark also visible in the stereoviewer. At this point a 
paper print of one of the diapositives is placed in the reference 
viewer and the viewer indicator is switched to synchronize it with 
the proper diapositive. The print is then shifted to superimpose 
the first fiducial mark over the viewer indicator light. Then the 
"END" key is depressed which stores the fiducial mark's machine- 
coordinates and sends the scanners to the vicinity of the second 
(opposite) fiducial mark. Again both scanners are brought into 
precise registry under the reference mark. The paper print in the 
reference viewer is rotated about the previously established 
fiducial mark, bringing the second fiducial mark into registry. 
This action completes the "interior orientation" procedures in the 
UNAMACE and registers one photograph to its corresponding diapositive. 
Depressing the "END" key stores the second fiducial mark's machine- 
coordinates in the computer and initiates the calculation of transla- 
tion and rotation constants which relate the diapositive coordinate 
38 
©