A radiograph is made of an object with a width of 3 mm using an x-ray tube with a 2 mm focal spot at a source-to-film distance of 100 cm. The object being imaged is 15 cm from the film. Find the size of the image and the size of the blurred region at its edges.
By means of a diagram, discuss what effect will be produced on a film when a focused grid designed for 100 cm is used at 150 cm.