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Let us ask how interchange of stereoscopies can be achieved and see whey, 
ee Whether (his 
a clue. Hs See 
For the Multiplex type of instruments it is possible to interchange the rg gequidist 
blue-filters before the eyes or at the projectors. Separate optical paths of AUN eases | 
SD 
usually permit à Dove ly The 
: ; : Drism +, 
electro-magnetic phase switch rotate in each of the RM images 
over 10( ses TR sercopsi 
| rectifier (I. s 100 degrees Or to tency, Nm 
M » | T the two paths with respect d Va 
> : [ 3 oculars. qu ıhotog Ta 
gasdischarge | i ; , 
| Z7 lamp—~,— It will be clear hat à dange o 
€ > & 7 ipia that fhe 
ma! c Jj 
2 photograph Qanipu ations take Some fi 
while the processes of Stereo 
; sas jt 
d dq» -— — objective VISION are rapid ones os 
tha : = LS Ad 
5 ' these manipulations 
b. RB — nus pula lons as wn, 
semi-reflecting prism — | eir eitect bring about With thon 
| à certain degree of confus 
f | These are reasons Why these ne 
Dv thods are not full wi 
rotating shutter Et Ot Tullproof i te 
| synchron. results and une table in the 
motor ) it 1comfortahle Tn td 
Mn: / practical application. 
N = The ide: ; 
\ he ideal way to Interchang 
) Stereoscopies would be one that 
Qy operated by merely pushing a by. 
: ton, timeless to the observer a 
| without effecting in any way fk 
A, position of the stereoscopic en: 
oculars A.C. suppl 5 Tc . 
: Y ponents.  Stereophotogrammeri 
x instruments can be easily ado 
Fig. 2. : On 
to achieve before mentioned if 
way of interchanging Stereostopis 
A primitive scheme is shown in figure 2. It is necessary to illuminate the photograjis 
with alternate radiating light sources and to separate the images that are received at lil 
eyes by a shutter rotating synchronous with the alternate radiating light sources. Inte: 
change of stereoscopies is obtained by an electro magnetic phase switch at the AC. supply 
for the lamps circuit, while the cir- 
; ; ; ; 0, base (B) 0, 
cuit of the synchron shutter is left 
uneffected. 
'atents are applied for by the 
author. 
The tests were performed by 
five persons at Kern & Co., Aarau. 
T i height 
I'he results, that were derived from umm 
their measurements on an instru- 
ment of the mirror stereoscope type 
show an average decrease of the 
mean square error in height of P — 
x ; : 1) Bj 
50% for Stereo-Direct-Invers as 1| Binocu 
. . : J 
compared with single stereoscopic | | | | BN. Y B. 
observation. The still more chal- ; 
lenging result is the elimination Fig. 3. d 
. : x > new 
of the subjective observation error. interesting VB 4 i 
à : : ; it is interests“ § Aero 
It opens the way to more reliable work, singular as well as in shiits. It is tr 
5 : . : 1077, 
consider the S.D.I.-method versus the doubled base/height ratio.