Basic geometry of this X-ray machine


In this video, a guy shows why tilting the arm of a xray machine doesnt make different shadow and why it doesnt make an image cut off with Bucky’s grid.

Can someone explain please! Thanks!

In: Mathematics

If the light source doesnt move and the object doesn’t move, why should the shadow move?

Don’t think of the source of light rotating. Turn on a table lamp and put a pencil under it. Notice where the shadow on the pencil is. Then cut a hole out of a piece of paper and put it between the lamp and the pencil.

Move the sheet of paper around. The pencil’s shadow won’t move because neither the light nor the pencil moved.

The only thing that moves is the shadow from the paper because that’s the only thing moving.