Stereoscopic Photographs

Let F be the focal distance of the camera, A the altitude (or distance) of the camera above the scene, P the distancepp on the contact print (not an enlargement) and S the same distance on the ground. We can write (similar triangles)  

Let H be the height of the camera (satellite, aircraft, or distance on the ground between the lens and the scene), b the base line on the stereoscopic couple, i.e. the distance between the optical centers of the right-hand and the left-hand photos, and dp the parallax difference. The height of the object studied is thus  

Very often, H must be replaced by a calculated value. To do this let / be a known distance on the ground (for example between two crossroads), / the focal length of the camera and d the value D on the photographic plate obtained by contact printing, not by enlargement. H= Dfjd, to be substituted for //in the preceding equation. 

It is very important, for common sense reasons, to work on a photographic print obtained by contact from the original negative. It is equally evident that, if we know precisely the value of the linear enlargement, we can replace / by a number obtained when / is multiplied by the enlargement value. 

---

FIG. 23.20 Stereoscopic photographs showing the structures of the three forms of silica, (a) cristobalite, (b) quartz, and (c) tridymite, as systems of linked Si04... 

DIFFERENCE OF PARALLAX HOW TO DERIVE THE HEIGHT OF AN OBJECT FROM AERIAL STEREOSCOPIC PHOTOGRAPHS... 

Aerial photographs in stereoscopic pairs for selected years. Records from local and state health department and conservation agencies... 

The correct interpretation of an air photo depends not only on the expertise of the interpreter, but also on the resolution of the photo and on the sharpness of its focus, in other words, on the quality of the cameras, films and the photographing technique (e.g., compensation for the motion of the airplane). The technique of stereoscopy in particular has effected great improvements in air photo interpretation. In this technique, two photos of the same area are taken in rapid succession. Due to the motion of the airplane, the angle at which the photos are taken will have changed somewhat in this brief time. If these two slightly different photos are then viewed through a stereoscope, one picture with each eye, the result is a three-dimensional effect that allows for the easy differentiation between raised and flat objects on the ground.1... 

Ibid., 730-31. The stereoscope, a common parlor device, visually unites two different photographs of the same scene taken from different angles to create a three-dimensional effect. Erlenmeyer s metaphor was not intended to imply a stereospatial or stereochemical view of formulas. His point was that different formulas are intended simply to view the same molecular object from different (mental) points of view, a point made earlier, e.g., by Kekule. 

Measuring instrument is equipped with a mount device that is able to move horizontally and the camera can be rotated, the device also has a slider that can move horizontally to take stereoscopic pictures (Photograph 1). 

Stereoscopic images were taken, as shown in Photographs 6 and 7, and we created as geological map like Figure 5, with the rock joints written and... 

Photograph 6. Result of joints measured by stere- Photograph 7. Result of joints measured by stereoscopic survey of slope (left side). oscopic survey of slope (right side). 

Fig. 2. Structure of matrices (left), and stereoscopic microscope photographs of analyte-matrix mixtures on a mirror-polished stainless-steel plate (right). The location of the third negative charge on the CA moiety in G3CA has not been clarified.

---