TOPOGRAPHIC SURVEYING

This is an example of one of a series of photographs taken by the RAF in 1946.

The RAF initially conducted aerial reconnaissance flights across the UK for military purposes during the Second World War, but they were continued in peacetime once their value for topographic surveying was recognised.

By the end of the war the art had been perfected and the RAF had cameras with a focal length of up to 40 inches - a technology capable of capturing decent images of traffic on the street from 35,000 feet.

With the correct optical viewer the images could be viewed in primitive stereoscope - buildings appeared in 3D.