LS 
(posure 
"ng to it 
N 
means 
nage co- 
inknown 
quisition 
otos and 
rdinates. 
cans of 
d'in case 
3.1 Photo taking 
As it was mentioned above the photos 
taken of hard plaster cast have been 
made within a test network which came 
into being from control points. In order 
to avoid identification errors and to 
make the procedure of evaluation easier 
we projected a regular network of 
gratings on each image from a projector 
(photos 1., 2.). During photo taking the 
network of grating and the plaster cast 
were fixed in position ensuring the 
projected mark to remain on the same 
point of the plaster cast on every image. 
Photo 1. shows the arrangement of 
photo taking, photo 2 is an image of the 
object. 
  
Photo 1.: Photographical arrangement 
with DCS 420 
Applying the apriori accuracy planning 
methods of the multi-station close-range 
photogrammetric network our result was 
as it follows: the expected accuracy of 
0,3 mm can be assured also by non- 
metric cameras built up for a 
reproduction reason if we choose an 
adequate high value of redundancy by 
the right election of the viewpoints and 
163 
  
Photo 2.: The image of the plaster cast 
the number of control points. The 
applied non-metric camera was of Nikon 
type developed for the reason of 
reproduction. We did not use 
complementary appliance (like a base, a 
ring light) because of the nature of the 
task. Among the applied digital 
intstruments the use of Kodak DCS 
(photo 1.) became customary in 
photogrammetry. At start there were a 
lot of literary experiences beforehand 
and we had some accuracy 
investigations which proved that by 
using this instrument it 1s possible to 
obtain a 1/20 pixel image co-ordinate 
mean square error in the image space. 
The use and applicability of Dicomed 
DDC 7520 (photo 3.) is possible only 
among certain limits. The main cause of 
this is that the camera is not really 
portable it was developed expecially for 
laboratory conditions and it contains 
only one row of sensors so observing 
the process of photo taking scrupulously 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B5. Vienna 1996