What is the primary purpose of a filter in radiography?

In radiography, the primary purpose of a filter is to reduce the low-energy x-rays that reach the patient. Low-energy x-rays are less effective at producing diagnostic images and can increase the radiation dose to the patient without contributing useful information to the image. These low-energy x-rays are often absorbed by the patient's body rather than contributing to the formation of a radiographic image.

By using a filter, radiographers can selectively allow higher-energy x-rays to pass through while absorbing the lower-energy, less useful radiation. This process not only helps to improve image quality by enhancing contrast but also minimizes unnecessary radiation exposure to the patient. Therefore, the use of filters is essential for both optimizing the diagnostic efficacy of radiographs and ensuring patient safety.