Increasing the energy of x-ray or gamma rays has what effect on the characteristic curve?

Increasing the energy of x-rays or gamma rays, while keeping other factors constant, typically has little effect on the shape of the characteristic curve. The characteristic curve, which represents the response of a radiographic film or screen to radiation intensity, is influenced more so by factors such as film processing and the energy of the radiation only moderately affects it.

X-rays and gamma rays of higher energy can provide better penetration and contrast for certain materials, enabling greater detail in radiographic images. However, the fundamental relationships portrayed in the characteristic curve—such as exposure and resulting density—remain largely consistent, indicating that the overall shape of the curve is stable under varying energy levels. While variations in optimum energy might refine contrast or detail, the primary characteristics of the curve itself tend to remain unchanged.