IPA: /ˌæpəˈkrɒmətɪk/
KK: /əˌpɒkrəˈmætɪk/
A term used to describe a lens that has been designed to eliminate both color distortion and spherical distortion, allowing for clearer and more accurate images.
The apochromatic lens provided sharper images than the standard lens.
Apochromatic → It is formed from "apo-" (meaning away from) and "chroma" (from Greek "chroma", meaning color) and the suffix "-tic" (meaning pertaining to). The word describes lenses that are designed to bring colors to a common focus, thus correcting chromatic aberration, or the distortion of colors.
Think of 'away from' ('apo-') and 'color' ('chroma') to remember that 'apochromatic' refers to something that corrects color distortion.