A theoretical and experimental study of the optimal thickness of a front lead screen and the best choice of film to be used for gamma-radiography using ₁₃₇Cs as the source and a bronze wedge (2 to 32 millimeters in thickness) as the test sample. The optimal thickness of the front lead screen was decided as 0.1-0.3 millimeter. Two types of x-ray film, Fuji Medical x-ray film (RX) and Fuji industrial x-ray film (IX 100), were compared and the IX 100 film was found to be suitable because of its optimal film contrast value when the bronze object is small. See also AATA 21-1038 for related study.