The following is from Volume II of the House Select Committee on Assassinations, page 427.
Mr. MCCAMY. Suppose that we have a rifle for which the midpoint is known, and suppose we have a camera. The two elements shown are the lens and the film.
Point A on one end of the rifle is imaged by the lens at A-prime. Point B at the center is imaged at B-prime. Point C at the other end is imaged at C-prime.
These two lengths on the rifle are equal. They are 14 inches each. So, from A to B is equal to B to C. However, when they are imaged over here, A-prime to B-prime is only 1-1/2 inches, while B-prime to C-prime is 4 inches.
Mr. FITHIAN. Is what?
Mr. MCCAMY. Four inches.
Mr. FITHIAN. Four inches.
Mr. MCCAMY. So, you can see that because the rifle is tilted away from the camera, the size of the images changes over here. This is a very known phenomenon in photogrammetry.