Object: "Old Museum 11 , St. Gallen
17'»
Camera:
Wild P 31 , f
= 10 cm
No. of photographs:
l 2
Photographic disposition:
Normal case
Approximate picture scale:
l : 200
Base ratio:
l : 6
Film:
Ilford FDP 4,
18 DIN
Surface area photographed:
1450 m 2
Autograph:
Wild A 10
Plotting scale:
l : 50
Time required for
Reconnaissance, control point mea
surement and photography:
44 hours
(15 %)
Photo lab work:
10 hours
( 3 %)
Plotting of 12 models:
200 hours
(67 %)
Organisation, discussion
9 hours
( 3 %)
Inscription and supplementary
work (clean copy of drawing
is done directly with the mapping)
36 hours
(12 %)
A three-man team carried out the outside work. The time and cost
involved in making the same measurements with tape measure and
plumb bob, including the setting up of scaffolding and the time-
consuming manual methods which nonetheless never do cover the
entire object would be significantly greater. Similar studies have
demonstrated the photogrammetric plot of a façade can save 60 %
of the time needed for a manual plot. The use of the Wild P 31
super-wide-angle camera would result in a further saving of time.
The surface area covered by the camera at distance D is 5 D^. With
the wide-angle camera, f = 10 cm, under the same conditions only
one-fifth of the object surface could be covered.
The photography/plotting time ration is quite remarkable: previous
experience indicates a 1:5 ratio. The efficiency of the new super-
wide-angle lens is not under discussion.
These figures have been confirmed by the experience of other inst
rument users. For example, the following data is derived from an
archaeological excavation at St. Frambourg in France:
Object: Archaeological excavation - St. Frambourg, France
Camera:
No. of photographs:
Photographic disposition:
Surface area photographed:
Wild C 120, f = 6.4 cm
4
Normal case
275 m2
