What material are filters commonly made out of in radiography?

In radiography, filters are primarily made from aluminum due to its advantageous properties. Aluminum effectively attenuates low-energy X-ray photons that do not contribute useful information to the image while allowing higher-energy photons to pass through. This process enhances image quality by reducing patient exposure to unnecessary radiation.

The use of aluminum filters helps to improve the beam quality by creating a more uniform distribution of X-ray energies, which results in better contrast and reduces scatter radiation. The lightweight and durable nature of aluminum makes it an ideal choice for filters in radiographic equipment.

Other materials, such as lead, are denser and are primarily used for radiation shielding rather than filtering; they block a wide spectrum of X-rays rather than selectively attenuating lower-energy photons. Plastic may not provide effective filtration as it does not have the necessary atomic number or density to filter X-rays effectively. Copper, while having good X-ray absorption properties, is not typically used for filters because aluminum is more efficient and cost-effective for this purpose.