More than a few have been, at some point in time, used for commercial refracting telescopes. Following table lists examples of such objectives, from those with small reduction in secondary spectrum, to those fulfilling the formal apochromatic condition.

Chromatic aberration of a single lens causes different wavelengths of light to have differing focal lengths. An apochromat, or apochromatic lens (apo), is a photographic or other lens that has better correction of chromatic and spherical aberration than …

2024年10月8日 · The Svbony SV555 is a 243mm prime manual focus lens designed for deep-sky photography, featuring a petzval objective structure with a triplet lens and ED, providing a clear image without aperture blocking. Its 44mm full-frame offers a wide field of view.

Perfect for astrophotography and observation, Explore Scientific’s apochromatic refractors reveal the universe with stunning clarity and true color. Available in apertures from 80mm to 165mm, these triplets have a trio of air-spaced lenses, superior ED glass and proprietary coatings on all air-to-glass surfaces.

Glass combinations that do not achieve this level of secondary spectrum correction, but are better corrected in that respect than standard achromats, are often referred to as semi-apo objectives. But correcting for secondary spectrum alone does not guarantee chromatic performance significantly better - if at all - from an ordinary achromat's.

Unlike reflector telescopes that rely on mirrors, apochromatic refractors use lenses to deliver sharp, focused images directly through the eyepiece. If you have attached a camera to your telescope, you will appreciate crisp images with excellent ‘ color correction .’

2024年11月2日 · Apochromatic telescopes, often referred to simply as ‘apo’ telescopes, offer a solid solution to the pesky problem of chromatic aberration. These refractor telescopes are specifically designed to align colors more accurately, paving the …

The Askar 160APO adopts a triplet air-spaced APO lens design, including one piece of ED glass. ED glass, also known as low-dispersion glass, is a type of optical glass specifically designed to reduce chromatic aberration.

Our top pick for the best apochromatic refractor telescope is the Sky-Watcher EvoStar 120 APO. The EvoStar ED refractor lens assembly utilizes a proprietary combination of matched lenses, designed to deliver optimum visual and photographic performance.

Svbony SV555 professional astronomical photography telescope APO is designed for deep-sky photography. Petzval objective lens structure includes a triplet lens and 2-ED glasses offering a clear image without aperture blocking. 44mm full frame …