We use Optical Character Recognition (OCR) during our scanning and processing workflow to make the content of each page searchable. You can view the automatically generated text below as well as copy and paste individual pieces of text to quote in your own work.
Text recognition is never 100% accurate. Many parts of the scanned page may not be reflected in the OCR text output, including: images, page layout, certain fonts or handwriting.
Fig. 4. Front side of the Stereomeasure (built in 1950), a calculator for
relating D, A, M, fc> tc, cot <p and md for all shooting conditions
likely to be encountered in the studio and on location.
the point on which the camera axes are converged is distant D\ from the camera. The half-angle of convergence being denoted by </?, it is evident that
, tan -,
(9)
where tc is in inches, and D\ in p. In terms of d\, the distance in inches from the camera to the point of convergence, we may write
-i tc
<f> = tan
(9;
If, which is preferable, each optical system is laterally displaced inward through a distance, h, in relation to the film, we may write instead,
_
2K
Or, expressed in terms of d\t
, fete
h = o~7 2d\
(10)
(lOa)
We suggest that h (and its projection counterpart, H} be denoted by the term edge-in to differentiate it from physical convergence of camera and projector axes which is often conveniently described as toe-in.
The Stereomeasure
With the aid of the reciprocal distance system and Eq. (8) and its variants, an experienced stereotechnician can make all the necessary depth range and depth content calculations in his head, finally obtaining the values of <p or h from simple tables. However, as an aid to memory, these relationships and others have been embodied in a calculator, the Stereomeasure, which was designed and built in 1950 and has since been used for every one of our productions. One side of this calculator is shown in Fig. 4. It gives immediate numerical answers to all problems of how the camera should be set up to produce the effect in space de
Spottiswoode, Spottiswoode and Smith: 3-D Photography
261