Creating small-format camera coordinates: 3 techniques for interior orientation

Interior orientation (the initial step in comparator-based photogrammetry) requires a set of known photo-coordinates to act as reference points. Fiducials serve this purpose on metric survey cameras as do reseau targets on small-format, semi-metric cameras. Standard small cameras, however, are equipped with neither fiducials nor a reseau plate. To overcome this problem three attempts were made to create small-format camera coordinates. In the first method a clear template with four calibrated cross-hair targets was superimposed on a 35 mm diapositive (after the film was exposed). The second technique installed fiducials in the 35 mm camera body. In the third technique, original 645 imagery was custom enlarged so as to expose the entire frame edge on the print.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.