Which technique could effectively reduce the amount of scattered radiation reaching the film during exposure?

Using masking techniques to cover the test piece can significantly reduce the amount of scattered radiation that reaches the film during exposure. Masking involves placing a barrier or material that can absorb or deflect some of the incoming radiation, thereby minimizing the scattered radiation that contributes to unwanted exposure on the film. This results in a clearer image because less scatter means less fogging, enhancing the contrast and detail visible in the radiograph.

In radiographic testing, scattered radiation can obscure important details in the image, making it difficult to identify flaws or features in the test material. Masking strategically allows for better control of the exposure conditions and improves the overall quality of the radiographic image.

Increasing the radiation source activity, while it might provide more primary radiation, could also increase scattered radiation levels without addressing the root issue of scatter control. Using thinner film may not necessarily reduce scatter but could affect the film's sensitivity and contrast. Lastly, changing the film type might alter the film's response to radiation but does not inherently address scatter reduction directly in the same way masking can.