Apochromats are refractors whose lenses are laid out in such a way as to combine at least three colours at a common focal point. This suppresses the chromatic aberration that is typical of refractor telescopes. Without this correction, bright objects like the Moon or the planets would have disruptive colour fringes.
Omegon
Apochromatic refractor Pro APO AP 130/910 OTA
$ 3,190.00
William Optics
Apochromatic refractor AP 51/250 RedCat WIFD
$ 1,160.00
Skywatcher
Apochromatic refractor AP 72/420 EvoStar 72 ED DS Pro OTA
$ 429.00
Askar
Apochromatic refractor AP 103/700 Triplet OTA
RRP:
$ 1,730.00
Our price:
$ 1,510.00
William Optics
Apochromatic refractor AP 51/178 MiniCat WIFD OTA
$ 1,160.00
Omegon
Apochromatic Refractor Pro APO AP 71/490 Quadruplet OTA
$ 769.00
William Optics
Apochromatic refractor AP 56/269 UltraCat 56 WIFD
$ 1,730.00
Omegon
Pro APO AP 72/400 Quintuplet OTA Apochromatic refractor
$ 1,390.00
Askar
Apochromatic refractor AP 55/264 SQA55 OTA
$ 1,160.00
William Optics
Apochromatic refractor AP 71/350 RedCat 71 WIFD
$ 1,730.00
William Optics
Apochromatic refractor AP 108/518 UltraCat WIFD
$ 4,640.00
Omegon
Apochromatic refractor Pro APO AP 96/575 Triplet ED FCD-100
$ 1,290.00
Askar
Apochromatic refractor AP 71/490 Flat-Field 71F OTA
$ 1,090.00
William Optics
Apochromatic refractor AP 91/448 BlackCat 91 WIFD OTA
$ 3,710.00
Omegon
Apochromatic refractor Pro APO AP 106/700 Triplet ED FCD-100
RRP:
$ 1,990.00
Our price:
$ 1,899.00
Omegon
Apochromatic refractor Pro APO 85/560 ED Triplet CEM26 LiteRoc
RRP:
$ 3,958.90
Our price:
$ 3,890.00
Skywatcher
Apochromatic refractor AP 62/400 Evolux-62ED Star Adventurer GTi Wi-Fi GoTo SET
RRP:
$ 1,740.00
Our price:
$ 1,630.00
ZWO
Apochromatic refractor AP 65/416 FF65
RRP:
$ 1,390.00
Our price:
$ 1,280.00
ToupTek
Apochromatic refractor HOPE D60 60/280 f/4.66
$ 1,290.00
Sale price:
$ 899.00
Omegon
Apochromatic Refractor Pro APO DoubleED AP 40/180 Sixtuplet OTA
$ 499.00
ZWO
Apochromatic refractor AP 107/749 FF107
$ 2,780.00
William Optics
Apochromatic refractor AP 132/925 Fluorostar Gold OTA
$ 6,200.00
Omegon
Apochromatic refractor Pro APO AP 104/650 ED OTA + 2'' Field Flattener
RRP:
$ 2,048.00
Our price:
$ 1,990.00
William Optics
Apochromatic refractor Pleiades 111 AP 111/528 Astrograph OTA
$ 4,870.00
Askar
Apochromatic refractor AP 72/400 FRA400C Astrograph
$ 1,160.00
Skywatcher
Apochromatic refractor AP 120/900 Evostar 120 EDX
$ 1,330.00
Vixen
Apochromatic refractor AP 80/600 ED80Sf Advanced Polaris
$ 2,370.00
Askar
Apochromatic refractor AP 40/180 FMA180 OTA
RRP:
$ 750.00
Our price:
$ 498.00
Omegon
Apochromatic Refractor Pro APO AP 61/360 Triplet ED OTA
$ 599.00
Askar
Apochromatic refractor AP 130/1000 130PHQ OTA
RRP:
$ 5,100.00
Our price:
$ 4,500.00
Askar
Apochromatic refractor AP 120/840 Triplet OTA
$ 2,310.00
William Optics
Apochromatic refractor AP 81/478 GranTurismo 81WIFD OTA
$ 2,310.00
Omegon
Apochromatic refractor Pro APO AP 108/600 Quintuplet OTA
RRP:
$ 2,990.00
Our price:
$ 2,899.00
Skywatcher
Apochromatic refractor AP 80/600 EvoStar ED OTA
$ 930.00
William Optics
Apochromatic refractor AP 51/250 SpaceCat WIFD OTA
$ 1,140.00
Omegon
Telescope Pro APO 72/400 Quintuplet CEM26 LiteRoc
RRP:
$ 3,748.00
Our price:
$ 3,490.00
Refractors are telescopes where the objective consist of one or more glass lenses. The lens refracts light to a focal point. However, the exact location of the focal point depends on the wavelength (colour) of the light. This causes chromatic aberration which is noticeable as a coloured fringe around bright objects. In physics, this dependence of refraction on wavelength is called dispersion.
There is no really precise definition of the term apochromat. Most apochromats have an objective consisting of two lenses, in which a special glass is deployed. This so-called ED glass has particularly low dispersion (the abbreviation ED stands for extra-low dispersion). The ED apochromats provides a largely pure-colour image.
An objective consisting of three or four lenses will provide an even sharper image. These apochromats are called triplets or quadruplets. These can be as good as mirror optics in term of colour purity.