What is chromatic aberration and how can you reduce it in editing or by lens choice?

• A. Chromatic aberration is color fringing at high-contrast edges; reduce by lens correction profiles, stop down slightly, or use higher-quality lenses; in post, remove CA.
• B. Chromatic aberration is motion blur from long exposure.
• C. Chromatic aberration is digital noise in shadows.
• D. Chromatic aberration is the loss of color in low light.

Answer: (A)

Chromatic aberration is color fringing caused by a lens's dispersion, meaning different colors don’t all come to the same focus. It often shows up as purple or green halos along high-contrast edges, like a dark branch against a bright sky. You can reduce it by using lenses designed to minimize dispersion (better glass and optical design) and by stopping down the aperture a bit, which helps both lateral (edge-based) and axial (out-of-focus, or longitudinal) chromatic aberration to become less noticeable. In editing, you can apply lens corrections that automatically fix chromatic aberration or manually adjust the color-channel alignment to remove fringes along edges. The combination—quality optics, appropriate aperture, and post-processing corrections—yields the cleanest result.