Final answer:
Option 2: The primary purpose of a filter in X-ray machines is to reduce the number of long wavelength X-rays reaching the patient, thereby minimizing radiation exposure and indirectly improving image quality.
Step-by-step explanation:
The main purpose of a filter in radiography, such as in X-ray machines, is to reduce the number/amount of long wavelength X-rays in reaching the patient. This process, known as filtration, is essential for radiation protection as longer wavelength X-rays have less energy and are less capable of penetrating the body to produce a clear image. Therefore, these unnecessary X-rays are absorbed before reaching the patient to minimize radiation exposure and potential harm. Filters in medical imaging also indirectly help in improving the image quality by removing the less useful part of the X-ray spectrum which contributes to image fog and reduces the contrast of the resulting image.
The main purpose of a filter in medical imaging, particularly in X-ray techniques, is to reduce the number/amount of long wavelength x-rays that reach the patient. Filters are used to selectively remove or absorb specific wavelengths of X-rays, helping to improve image quality by reducing unwanted scatter radiation and focusing on the desired wavelengths of X-rays. Additionally, proper shielding and limiting exposure time are important radiation protection measures in reducing the dose received by the patient and the operator.