A non-achromatic objective is an objective lens which is not corrected for chromatic aberration. In telescopes they can a be pre-18th century simple single...

non-achromatic objectives were constructed with very long focal lengths to mask the chromatic aberration. An Achromatic telescope uses an achromatic lens...

An achromatic lens or achromat is a lens that is designed to limit the effects of chromatic and spherical aberration. Achromatic lenses are corrected...

of an achromatic lens.[citation needed] Such telescopes contain elements of fluorite or special, extra-low dispersion (ED) glass in the objective and produce...

telescope which is not directly comparable because it uses a single element non-achromatic lens, and the short-lived Great Paris Exhibition Telescope of 1900....

single element non-achromatic objective lenses that suffered from interfering rainbow halos (chromatic aberration) introduced by the non-uniform refractive...

bigger the number, the greater the effective magnification. Higher quality achromatic lenses commonly lack a strength specification in diopters. It can be inferred...

blue and yellow). Each telescope may have individually designed non-achromatic objectives to focus the desired wavelength of light which is paired with...

a central hole in the main mirror. The achromatic lens, which greatly reduced color aberrations in objective lenses and allowed for shorter and more...

were refractors with non-achromatic objectives (single lens), speculum metal reflectors, refractors with achromatic doublets objective (doublet lens), and...

Aerial telescopes overcame the optical shortcomings of 17th-century objective lenses, etc. Optical telescopes can be classified by three primary optical...

His major achievement at the time was the improvement of the achromatic microscope objective. Today he is best known for the eponymous Plössl telescope...

an "achromatic doublet of 11.6 inches clear aperture and focal length 19ft 6in". Although there had been very large (and unwieldy) Non-achromatic aerial...

positive lens has to be thicker. Achromatic doublets therefore have higher thickness and weight than the equivalent non-chromatic-corrected single lenses...

source, only the first, the diffraction grating interferometer, is truly achromatic. Here the vertical scanning or coherence probe interferometers are discussed...

prism Non-Gaussianity Non-Newtonian fluid Non-abelian gauge transformation Non-achromatic objective Non-autonomous mechanics Non-contact force Non-critical...

instruments with much larger objectives.[citation needed] Chester Moor Hall is credited with designing the first achromatic lens in 1729, which consisted...

three groups. The groups may be two achromatic doublets with a double convex singlet between them or may all be achromatic doublets. These eyepieces tend not...

experiments in photography. In 1829[citation needed], Chevalier created an achromatic lens (a two-element lens made from crown glass and flint glass) to cut...

at high chroma, deviating most from an achromatic signal such as linear luminance Y {\displaystyle Y} or non-linear lightness L ∗ {\displaystyle L^{*}}...

developed a simple 2-lens ocular system in the late 17th century that was achromatically corrected, and therefore a huge step forward in microscope development...

For an achromatic dispersive lens the converse must be adopted. This is, at the present day, the ordinary type, e.g., of telescope objective; the values...

opposite ends of the spectrum). Some examples of necessarily non-spectral colors are the achromatic colors (black, gray, and white) and colors such as pink...

simple lenses usually are constructed using several elements to form an achromatic lens. But such simple lenses are not telephoto lenses, no matter how extreme...

producing his own telescopic sight, used an original design incorporating achromatic lenses such as those used in telescopes, and improved the windage and...

diameter approximately the same as the lens focal length Anastigmat is an achromatic lens used to reduce or eliminate astigmatism designed specifically for...

Dorpat’ refractor, a telescope that combined other innovations, such as an achromatic lens and Fraunhofer's "German equatorial mount", making it the prototype...

glass available (soda-lime crown and lead flint), invented the first achromatic doublet. His work was taken up by John Dollond in his Account of some...

appear colored. With the achromatic refractor, however, this is not the case. Newtonians explain this by saying that the achromatic refractor's crown glass...

enabled instrument maker Johann Georg Repsold in Hamburg to construct a new achromatic lens system in 1810. A main problem, among other difficulties, was that...