Measurement at very close range using microscope photogrammetry

This paper describes the use of photogrammetric for the measurement of objects only a few millimetres in size by using a 35 mm camera in conjunction with a stereoscopic microscope. It is intended not only to point out the attractiveness of the camera-microscope combination in very close-range measurements, but also to illustrate the successful development of a simple observing and computing routine despite the initial lack of any data about the camera-microscope system. The approach, which utilises a stereocomparator and a few elementary equations, demonstrates the advantage gained in close-range photogrammetric by the calibration of a number of parameters. The technique was successful in measuring depths on objects to precisions of 0.01 mm.