Achromatism Condition Lenses — the NEET Physics formula with its derivation, variables, validity constraints and worked solver.
Achromatism Condition (Lenses) This condition applies when combining two lens elements (an achromatic doublet) to minimize the total chromatic aberration. Chromatic aberration is the failure to focus different wavelengths (colors) to the same point. Achromatism requires that the total dispersion introduced by the combined system is zero. The condition is derived by setting the sum of the normalized contributions of the two elements to zero. This results in the relationship: P 1 1 + P 2 2 = 0 P 1 0 P 2 0 1 0 2 0 Confusing the achromatic condition with the simple thin lens formula (1/f = P). Assuming that zero dispersion means the lens has zero power (they are independent properties). Applying this condition to a single lens element.