achromatic

Examples of achromatic in the following topics:

• Combinations of Lenses

  • An achromatic lens or achromat is a lens that is designed to limit the effects of chromatic and spherical aberration.
  • Achromatic lenses are corrected to bring two wavelengths (typically red and blue/violet) into focus in the same plane.
  • The most common type of achromat is the achromatic doublet, which is composed of two individual lenses made from glasses with different amounts of dispersion Typically, one element is a negative (concave) element made out of flint, which has relatively high dispersion, and the other is a positive (convex) element made of crown glass, which has lower dispersion.
  • (b) Multiple-lens systems, such as this achromatic doublet, can partially correct chromatic aberrations, but they may require lenses of different materials and add to the expense of optical systems such as cameras.

• Unity and Variety

  • Any color that lacks strong chromatic content is unsaturated, achromatic, or near neutral.
  • Pure achromatic colors include black, white and all grays; near neutrals include browns, tans, pastels and darker colors.

• Aberrations

  • A chromatic aberration, also called achromatism or chromatic distortion, is a distortion of colors .

• The Telescope

  • With the invention of achromatic lenses in 1733, color aberrations were partially corrected, and shorter, more functional refracting telescopes could be constructed.