Noun:

ऑबर्न लेन्स,

achromat's Usage Examples:

It also utilizes achromat glass lenses in the objective-lens – the large 51 mm (2 in) one in front.

4 cm (23″) achromat Princeton, USA 1881 Chamberlin Observatory 50 cm (20″) achromat Colorado.

 106 link Edward Sang, On the achromatism of the four-lens eye-piece: new arrangement of the lenses, Proceedings.

reflectors had largely been passed over in favour of small achromats (2 lens refractors).

that the object-glasses of telescopes must forever remain imperfect, achromatism and refraction being incompatible.

Dollond"s son Peter invented the apochromat, an improvement on the achromat, in 1763.

Pure achromatic colors include black, white, all grays and beiges; near neutrals include browns, tans, pastels, and darker colors.

the two simple meniscus lenses with achromats for chromatic correction.

complementary colors, which are colors that cancel each other"s hue to produce an achromatic (white, gray or black) light mixture.

Look up monochrome, achromatize, achromic, or monochromatic in Wiktionary, the free dictionary.

plano-convex singlet eye lens and a cemented convex-convex triplet field lens achromatic field lens.

Another example of metachromatic dye (fluorochrome) is acridine orange.

tetrachromats, containing cone cells sensitive for red, green, blue and ultraviolet light.