from The Century Dictionary and Cyclopedia
- n. A lens system, designed by Abbe, consisting of a combination of ten lenses with homogeneous immersion. It is achromatic for three colors, and therefore free from secondary spectra, and aplanatic for two colors.
Sorry, no etymologies found.
Advanced glass formulations by Zeiss, Schott, and Abbe helped produce the first apochromat objectives.
An apochromat is corrected for three specific wavelengths of light -- usually red, green, and blue -- and brings those three wavelengths to the same focus, providing slightly sharper images than an achromat.