STEREOMICROSCOPE PHOTOGRAMMETRY FOR THE MEASUREMENT OF SMALL OBJECTS

TY - JOUR

T1 - STEREOMICROSCOPE PHOTOGRAMMETRY FOR THE MEASUREMENT OF SMALL OBJECTS

AU - Mitchell, H. L.

AU - Chadwick, R. G.

AU - McCabe, J. F.

PY - 1989/10

Y1 - 1989/10

N2 - A stereoscopic microscope has been used in combination with the body of a 35 mm camera to obtain stereophotographs, at scales up to 6:1, of objects only a few millimetres in size. Subsequent stereocomparator observations have been used to deduce height differences on the objects 10 a precision, for the mean of five sets of readings, of ±0.01 mm for closely spaced points. Using more widely separated points, the precision was estimated to be ± 0.05 mm. Depths were computed using × parallaxes after a number of parameters were fixed by calibration. The large convergence angle of the microscope axes was a crucial parameter; rotations about the camera axis were found to be significant variables.

AB - A stereoscopic microscope has been used in combination with the body of a 35 mm camera to obtain stereophotographs, at scales up to 6:1, of objects only a few millimetres in size. Subsequent stereocomparator observations have been used to deduce height differences on the objects 10 a precision, for the mean of five sets of readings, of ±0.01 mm for closely spaced points. Using more widely separated points, the precision was estimated to be ± 0.05 mm. Depths were computed using × parallaxes after a number of parameters were fixed by calibration. The large convergence angle of the microscope axes was a crucial parameter; rotations about the camera axis were found to be significant variables.

UR - https://www.scopus.com/pages/publications/0024837052

U2 - 10.1111/j.1477-9730.1989.tb00680.x

DO - 10.1111/j.1477-9730.1989.tb00680.x

M3 - Article

AN - SCOPUS:0024837052

SN - 0031-868X

VL - 13

SP - 289

EP - 299

JO - The Photogrammetric Record

JF - The Photogrammetric Record

IS - 74

ER -