(344)
neering surveys (1:500 to 1:5000) by the Munich Society of Photogrammetry
and for small scale surveys ar 1 : 200,000 made in connection with the expe-
dition to the Cordilliere Blanche. The construction of a small Zeiss Autograph
using a format 6'/» XX 9 cm is also reported.
In Austria terrestrial stereo photogrammetry is still employed but only a
little. Zeiss photo theodolites and stereo autographs are used. Plotting is done
at 1 : 12,500 scale; 3,000 sq. km were mapped between 1948 and 1951.
The Netherlands, Belgium, Finland, Sweden, and Switzerland reported no
surveys by terrestrial photogrammetry except large scale engineering surveys.
In France the Geographic Institute did not make a single survey by these
methods. The French Society of Stereotopography applied the method to 1:
: 1000 scale plans of steep valleys for public works, dams, etc.
II. Aerial Photogrammetry.
This report considers only the problems of aerial photography affecting
plotting and its precision; plates or film, wide angle cameras, etc.
Equipment U sed.
Several new wide angle cameras have appeared. Films are still very widely
used, notwithstanding the difficulties they present. On the whole each country
uses the same materials as before. However, the tendency toward wide angle
cameras which seemed strong at the Congress in 1948 does not appear to have
been wholely established in practice. Many countries still use cameras with nor-
mal field angles.
Plates and Films.
Among the organizations now using plates are the IGM of Florence (San-
toni camera with plates 13 X 18 cm and F — 195 mm), I.G.N. of Paris (S.O.M.-
Poivilliers cameras 13 18 cm, F — 200, 150 and 125 mm; and 19 X 19 cm, F=
125 mm; LG.M. of Brussells (the same cameras as S.O.M.- Poivilliers); the Swiss
Cadastral Service (Wild camera RC-7;15 X 15 em, F — 17 cm).
As in other countries, film is used by certain organizations and for certain
cases; the French LG.N. use S.O.M. film cameras 18 X 18 cm, F — 125 mm, to
map Territories of the French Republic where the scale of the map is to be
1/100,000, but they tend to use plates more and more even in these regions.
Belgium uses also the S.O.M. film camera f — 125 mm for surveys in the Bel-
gian Congo.
LG.M. of Florence use Santoni film cameras 18 X 20 cm, f — 165 and
135 mm.
The other countries do not take their negatives on glass, or they use glass
only occasionally in older normal-angle cameras.
Wide-Angle Cameras.
The wide-angle cameras used today were for the most part already made
in 1948 at the time of the last Congress. They are:
The Fairchild cameras having a Metrogon lens, format 9 XX 9 inches (23 X
25 cm) with a 6-inch (152 mm) focal length, and sometimes 5.2 inches
(130 mm) for film only;
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