What is the primary purpose of added filtration in an x-ray machine?

The primary purpose of added filtration in an x-ray machine is to absorb less penetrating x-rays. Added filtration involves placing a material, typically aluminum, between the x-ray tube and the patient, which helps to remove low-energy x-rays from the beam. These low-energy x-rays contribute little to the image quality and increase the dose to the patient without providing diagnostic information. By filtering out these less penetrating rays, the x-ray beam becomes "harder," meaning that it is composed of higher energy photons that have a greater likelihood of contributing to a useful image while reducing patient exposure. This enhances the overall safety and efficiency of the radiographic process.