(50) 
format of 18 x 18 cm. With the 
Nistri cameras an OMI normal 
orthoscopic reproducer is used. 
This operates on a horizontal 
bench. It can be used with 
pictures up to 30 x 30 cm on him. 
Reproductions are on 18 xl8 cm 
plates. its magnification can be 
varied from 1-1 to 0-46. The 
lens is an OMI Orthosix 20 cm 
f:6-3. A new instrument is the 
Nistri Universal Telescopic Re 
producer shown in Fig. 17. This 
consists of two parts, a projection 
camera which holds alens identical 
to that with which the photograph 
was originally taken, and a re 
producing camera which has the 
same characteristics as the optical 
system which will be used in 
viewing the diapositive produced. 
In all the printing devices ex 
posures are determined by expe 
rience. Measurements of negative 
temperature in one printer show 
that for an ambient temperature 
of 22°C a negative temperature 
of 27° is reached after 10 minutes, 
29° after 20 minutes, and 30° after 
30 minutes exposure. 
Fig. 17 Nistri Universal Telescopic Reproducer 
(film model) 
Netherlands 
KLM Aerial Surveys use Ilford glossy paper and Ilford diapositive glass 
plates. The paper is double weight except for certain mosaic applications where 
single weight is used. A diffused light contact printer with provision for dodging 
uses rubber pressure pads. Resolution tests on the printer are in progress. It 
has a temperature rise of 6°C after 30 minutes of printing. Ambient temperature 
is 19 to 20°C with varying humidity. Tray processing is used with occasional 
sensitometric control. The Royal Dutch Shell use bromide double weight paper 
and diapositive plates. Their processing procedures are similar to those of KLM. 
New Zealand 
Kodak white semi-matte paper is used in a printer having an inflated rubber 
pressure back. Exposure is based on experience. Tray processing is used. Prints 
are not ferrotyped.