Which statement correctly describes the relationship between Abbe value and chromatic aberration?

• A. Higher Abbe value increases chromatic aberration
• B. Higher Abbe value decreases chromatic aberration
• C. Abbe value has no effect on chromatic aberration
• D. Chromatic aberration is determined solely by power

Answer: (B)

Chromatic aberration comes from material dispersion: different wavelengths bend by different amounts and focus at different distances. The Abbe value quantifies how much a material disperses light. A higher Abbe number means less dispersion, so for the same lens power, the focal points for various wavelengths are closer together. That reduces longitudinal chromatic aberration and yields sharper, less color-fringed images. So increasing Abbe value decreases chromatic aberration. The other statements conflict with the fact that dispersion drives chromatic errors and that the Abbe value directly influences that dispersion; chromatic aberration is not determined solely by power.