Question

Due to the inverse square law, the image at the margin of the x-ray film will be slightly darker than that in the middle. Suppose a chest x-ray projection system has a perfect point source, and the source-detector distance is 2 meters. If we require that the intensity variation across the film (when no object is imaged) must be less than 5%, calculate the largest size of the film that we can use. Suppose a square film

Answer 1