Introduction: In the course of the thesis, we investigated how the object to image receptor distance influenced on object's size. Purpose: The purpose of the diploma work was to find out, how the object to image receptor distance influenced on object's size on radiogram. We regulated exposition conditions so that exposure index was the same, because we wanted to stop the influence of lower signal to noise ratio on contrast resoultion of radiogram. Methods: In the course of the thesis we performed a few measures. First we were changing object to image receptor distance in the range from 10 cm to 50 cm for 5 cm at the source to image receptor distance 100 cm and then we gradually raise it untill 140 cm. In each measurement we measured the length of third proximal phalange. Results: We found that the size of the third proximal phalange increase linearly if we increase the object to image receptor distance and leave source to image receptor distance unchanged. However as both distances change, the object to image receptor and the source to image receptor increase exponentially. Discussion and conclusion: By increasing the distance between the object and image receptor, the size of the object in the image increases. We found out that if we change the source to image receptor distance by as many centimeters as the object to image receptor distance is changed, the magnification in the image will be smaller.
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