Chromatic aberration is a common optical phenomenon that occurs when a lens fails to focus all colors to the same convergence point. This often results in a noticeable fringe of color along the edges of objects in an image. While chromatic aberration isn’t directly dependent on the brightness of an object, brighter objects can make its presence more noticeable. When there’s a high contrast between a bright object and its surroundings, the fringing caused by chromatic aberration can become more apparent. This is because the refractive index of lens glasses varies slightly with different wavelengths of light, causing the light colors to bend by different amounts.
Thus, while chromatic aberration itself isn’t influenced by an object’s brightness, brighter or high-contrast edges tend to reveal this imperfection more vividly in an image. To minimize chromatic aberration, optics may include special lens elements like extra-low dispersion glass or utilize post-processing techniques in digital photography.