THE “NISTRI,, PHOTOSTEREOGRAPH
MOD. BETA (1951)
FOREWORD
In the field of photogrammetrical instrumentation is now available
a new equipment conceived and manufactured by Ing. Umberto Nistrı:
the PHOTOSTEREOGRAPH MOD. BETA (1951), of universal features,
and of stereoscopical type.
it belongs to the universal plotters because:
1) it allows for all possible taking tilts, from the plumb point (na-
diral) or aerial one, to those however tilted, and to the horizontal or ter-
restrial ones.
2) it can use photograms obtained with different focals of taking
fields, through the employment of only two types of interchangeable ca-
meras and the adoption of a perfectly orthoscopic reproduction, which
one gets by means of a suitable photographic bench, furnished among the
accessories to the plotter itself.
The new Photostereograph can be considered as belonging to the ca-
tegory of the indirect mechanical projection plotters based on Porro’s
principle, although, as we are going to see, it has special peculiarities.
As it is known the principle consists in keeping unaltered the optical taking
complex (photograph-lens), confining the mechanic and optical means to
the determination of the spatial directions of luminous rays plotted by
means of telescopes or similar (1).
Ing. U. Nistri resorted to this principle since 1934, when he manu-
factured his first Photostereograph (2), (exhibited by him at the IV In-
(1) See: U. Nistri — I problemi della restituzione fotogrammetrica autografica
€ un nuovo retitutore fotogrammetrico universale a visione binoculare stereosco-
pica — (The problems of autographic photogrammetrical plotting and a new uni-
versal plotter with binocular stereoscopical vision). — Conference held at the Faculty
of Engineering of the Rome University on May 19, 1950 edited by « Rivista del Ca-
tasto e dei Servizi Tecnici Erariali» yearbook 1950.
(2) See: G. Cassinis — Il fotostereografo Nistri — (The Nistri Photostereograph)
- Communication to the IV International Congress of Photogrammetry, Paris 1934.
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