WORKING GROUP 1 
HEMPENIUS 
51 
(90°) is even worse than “poor”. The proper height of the exit pupil above 
the table is related to the inclination of the eyepiece and to the operator’s 
height. 
64. The Construction and the use of the stereoscope should be simple and 
adapted to the user; we can think of a phrase like “functional design”. Spare 
parts are useful, but are also an indication that the design is not perfect. 
Detachable accessories are a source of trouble. 
This paper was presented with the idea that the stereoscope deserves more 
attention from the designer and the user. We have proposed a consumer’s test 
and are looking forward to useful discussions from both parties concerned 
with this “simple” instrument. A publication on the measurements and the 
qualifications is in preparation. 
Discussion 
P. O. Fagerholm (Sweden) considered Mr. Hempenius’ specifications very valuable as a 
start for a discussion on the subject. The answer to his further questions was that, so far, no 
contacts had been made with the International Standardization Office or with Commission I 
of I.S.P. Asked whether he would actually start a classification along the described lines, the 
author said that the proposed specifications are first to be tested by the interpretation section 
of the I.T.C.