1) Photography equipment
Found on
https://www.crosswordclues.com/clue/stereoplotter
A stereoplotter uses stereo photographs to determine elevations. It has been the primary method to plot contour lines on topographic maps since the 1930s. Although the specific devices have advanced technologically, they are all based on the apparent change in position of a feature in the two stereo photographs. == Stereoplotter process == The ste...
Found on
http://en.wikipedia.org/wiki/Stereoplotter
No exact match found.
