. Elementary and dental radiography / by Howard Riley Raper . J, the plate carrier pushed in until theunexposed half of the plate comes under the window B, and the secondexposure is made. Since the two radiographs are made on the same platein this instance, special care should be taken to expose them each thesame length of time. Otherwise they will come up unequally in thedeveloping solution and radiographs of different densities will result. If the technic outlined above is followed, it will be found whenobserving the finished stereoradiograph that we see the part fromthe position of the tube
. Elementary and dental radiography / by Howard Riley Raper . J, the plate carrier pushed in until theunexposed half of the plate comes under the window B, and the secondexposure is made. Since the two radiographs are made on the same platein this instance, special care should be taken to expose them each thesame length of time. Otherwise they will come up unequally in thedeveloping solution and radiographs of different densities will result. If the technic outlined above is followed, it will be found whenobserving the finished stereoradiograph that we see the part fromthe position of the tube during exposure. Thus observe Fig. 339, whichwas taken with the palm of the hand toward the plate, a coin on theback of the hand, a needle under the hand. If, instead of following the technic as given, the first exposure bemade with the tube in position J and the plate as shown in Fig. 327,and the second exposure with the tube in position 1, after the plate isshifted; then, when observing the finished stereoradiograph, it is as STEREOSCOPIC RADIOGRAPHY 307. Fig. 337. Stereophotograph of the skull of a monkey, from Dr. John J. Kyles collection of skulls of vertebrates. though we saw the part from the position of the plate during itsexposure (see Fig. 340). This changing of position of observation may be accomplished alsoby interchanging the two radiographs—placing the right on the left andthe left on the right. Take Fig. 339, for example; interchange the radio-graphs and the stereoradiograph is the same as Fig. 340; or take and interchange the radiographs and the stereoradiograph is the sameas Fig. 339. The interchanging of radiographs must be done withoutinverting them, or the change of position of observation will not be ac-complished—the stereoscopic effect will remain the same and the part willsimply be viewed upside down.
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