be capable of reciprocal and absolute orientation; and it should be capable of 
handling superwide aerial photography (122°). Other characteristics include the 
capability to satisfy a medium-sized effective drawing area requirement; a large 
image-field diameter; a medium range of transmission ratios of machine- 
drawing board; and profile super-elevation ratios over a large range. 
d. The Stereotrigomat Universal Map-Plotting System was designed to 
utilize photography taken with cameras of varied focal lengths and formats, in 
cluding super wide-angle types; to produce profile traces in coordination with 
differential rectification by means of an electronic attachment (the Orograph); 
and to produce orthophoto prints. In accomplishing these ends the Stereotrigo 
mat acts, in principle, as an analog computer (which carries out central pro 
jective imaging by means of mechanical linkage); and it incorporates the theory 
of the reshaped raybeam and the affine technique. Additional characteristics 
include the following: a relatively large drawing board; magnification range for 
orthophotographs; size of orthophotography projection plane; transmission range 
from machine to drawing board and in many steps; observation magnification 
capability; and viewing field diameter. The Stereotrigomat is comprised of 
three separate units, namely, a main unit containing the necessary setting and 
operating elements required during the orientation and evaluation tasks, the two 
carriages for recording of the photographic images, and the stereoscopic device; 
a second unit containing the rectification and model computer; and a third unit 
containing the electrical group assembly and the control unit for the altitude 
profile track signalling device. Optional equipment consists of various types of 
computing and recording coordimeters and additional drawing boards. 
CARL ZEISS, OBERKOCHEN, WEST GERMANY. 
The Carl Zeiss Company, Oberkochen, West Germany, has introduced 
improvements to a previously developed item (Gigas-Zeiss Orthoprojector); one 
new item of automatic photogrammetric equipment (Planimat); and one new analog- 
type of equipment (Double Projector) during the period 1964-68. 
a. At the Lisbon Congress meeting of ISP in 1964 the Gigas-Zeiss (GZI) 
Orthoprojector was presented officially along with the 'Invited Paper" by R. D. Esten 
"Automatic Photogrammetric Instruments" and the "Presented Paper" by Messrs. 
Ahrend, Brucklacher, Meier, and Utz, "The Gigas-Zeiss Orthoprojector. " Since 
that time, delivery of the first series-produced instruments has been made along 
with two important developments, namely, development of a color processing 
attachment for obtaining color-correct orthophotos directly from air photographs; 
and development of a dropped-line attachment for orthoprojection of the aerial 
photograph and simultaneous photographic recording of the dropped lines. These 
are discussed below. 
(1) Provision is made for the insertion of from one to three glass 
correction filters in a slot of the GZI lamp housing. Single filters or combina 
tions of several filters thus inserted provide a means of correction of false colors 
present in the diapositive image. Through use of the proper duplicating film, 
colored orthophotos can be produced in several different versions. Image to copy 
versions such as positive to positive, negative to negative, negative to positive, etc.