Stand 219 —cont. 
Stand 219 —cont. 
Stand 220 —cont. 
Stand 220 —cont. 
The Kernon lens, being of the Hypergon type, and the human eye are not 
chromatically corrected. Therefore, almost monochromatic light con 
sisting of the 5461 A (green) and 5790 A (yellow) line radiations of the 
mercury discharge spectrum is allowed to emerge from the condenser 
optics, thus providing for an excellent image quality. 
There are three types of floating mark: 
1. A lighting point mark of which the intensity can be regulated by a 
rheostat. 
2. A black X-mark covering the whole field of vision for the stereoscopic 
elimination of j’-parallaxes. 
3. A black point mark. 
The floating mark can be accurately moved by means of a 1: 5 panto 
graph in planimetry and a 1 : 25 gear in height. The height of the floating 
mark can also be automatically corrected for earth curvature. 
A drawing machine of the polar coordinate type allows for any random 
transmission ratio between 0-3 x and 1-5 x the scale of the stereo model. 
The X- and T-coordinates and the base can be read directly in 0T mm. 
The elements of the relative orientation can be read directly on 0-01 degrees. 
The elements of the absolute orientation can be read directly in 0T %. 
The instrument is 2-7 m. wide, 3-3 m. long, 2-3 m. high and includes 
ample space for the operator(s). 
Power supply: 3 phase a.c., 380 volts, 50-60 c/s. 
PG2-Stereo Restitution Instrument. The PG2 is a stereo photogrammetric 
restitution instrument with mechanical reconstruction of the bundles of 
rays, incorporating the following features: 
The geometrically exact solution allows the independent elimination of 
the x- and y-parallaxes of Ato and A</>. The camera constants can also 
be set independently for the x- and v-directions in order to compensate for 
the differences in scale of the emulsion base. 
The image size may be up to 9 in. x 9 in. for any camera constant between 
80 mm. and 155 mm. 
Two types of illumination allow for the use of diapositives and paperprints. 
The magnifications 2 x , 4 x, or 8 x can be selected without changing 
oculars. 
Operators usually wearing spectacles do not need to take them off. 
Plotting may be done in 0-5 x to 2 x the photo scale. 
The relative elements of orientation can be read in 0-01 degrees. 
The absolute elements of orientation can be read in 1 %. 
49 
The instrument is 1-7 m. wide, 1-4 m. long, 1-4 m. high and includes 
ample space for the operator. 
Power supply: single phase a.c., 220 volts, 50-60 c/s. 
PLP-Para/lel Light Printer. The Parallel Light Printer is of the contact 
type with electronic dodging. 
The cross-section of the scanning beam can be selected in steps from 
1-100 mm 2 . The image size may be up 9 in. x 9 in. 
The instrument is 0-55 m. wide, 0-75 m. long, 0-90 m. high. 
Power supply: single phase a.c., 220 volts, 50-60 c/s. 
Activities and Products 
Kern & Co. Ltd., Aarau, Switzerland, founded in 1819 by Jakob Kern, is 
one of the oldest manufacturers of precision instruments. Kern's lines 
include a wide range of theodolites, tacheometers, levels and planetable 
outfits of striking modern .design, reliability and ease of operation. In 
photogrammetry a considerable amount of research is under way which 
will result in interesting new instruments. Kern's production programme 
comprises as well binoculars Focalpin with internal focusing, telescopes, 
drawing instruments, stereoscopic microscopes, medical instruments, the 
world famous lenses Switar and Yvar for the Bolex movie cameras, and 
optical systems for guided missile trackers. Kern instruments are sold in 
over eighty countries covering the five continents. 
Société d’Optique et de Mécanique de 
Haute Précision 
125, boulevard Davout, Paris 20ème, France 
Exhibits 
STAND 220 
Students Union 
Malet Street 
Third Floor 
Stereocomparator. A new achievement of the SOM, exhibited for the 
first time. 
Main characteristics: 
Synchronised control of the left and right crossed carriages holding the 
photographs (motors for high speed, handwheels for low speed). Foot 
control with pedals for additional motion of each photograph. 
Binocular microscope with variable magnification, including a device for 
permutation of the images from left to right in the eyepieces (aerotriangula- 
tion) and for their rotation (adjustment of transversal and stereoscopic 
parallaxes). 
50 
EXHIBITION GUIDE