Abstract
The sharpness, focus of skin distance and proper density in taking an enlargement high voltage chest radiography were examined by using a rotating anode X-ray tube with 0.3×0.3mm focus under the high voltage of 140 kVp. The following results were obtained from those experiments : The lowering of sharpness caused by enlargement of image were found in the half shadow of 0.3-0.6mm lengthened 1.7-2 times as long as that in usual radiolography. The focus of skin distance of 70 : 50cm was good. As for the density, the thickest one of 1.4-1.6 was most proper.
