telephoto magnification

Each CR photograph range was determined,combined with X-ray machine function,objective thickness and various position.

方法根据X线管焦点放大率和几何成像原理,求出最小焦点(F)-IP板的距离;综合考虑X机性能、被照体厚度和不同摄影部位,制定各部位摄影距离。