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 85/560 ED Triplet CEM26 LiteRoc
RRP:
$ 3,908.00
Our price:
$ 3,890.00
Omegon
Apochromatic refractor Pro APO 94/517 Triplet ED CEM26 LiteRoc
RRP:
$ 3,548.00
Our price:
$ 3,490.00
Omegon
Telescope Pro APO 72/400 Quintuplet CEM26 LiteRoc
RRP:
$ 3,348.00
Our price:
$ 3,290.00
Vixen
Apochromatic refractor AP 103/825 ED AX103S Sphinx SXP2 Starbook Ten GoTo
$ 9,900.00
Vixen
Apochromatic refractor AP 115/890 SD115S Sphinx SXP2 Starbook Ten GoTo
$ 9,000.00
Omegon
Apochromatic refractor Pro APO AP 66/400 ED SkyGuider Pro
RRP:
$ 1,735.00
Our price:
$ 1,650.00
Skywatcher
Apochromatic refractor AP 62/400 Evolux-62ED Star Adventurer GTi Wi-Fi GoTo SET
RRP:
$ 1,630.00
Our price:
$ 1,530.00
Skywatcher
Apochromatic refractor AP 150/1200 EvoStar ED EQ6R GoTo
RRP:
$ 4,910.00
Our price:
$ 4,570.00
Vixen
Telescope AP 80/600 ED80Sf Porta-II
$ 1,420.00
Vixen
Apochromatic refractor AP 80/600 ED80Sf Advanced Polaris AP-SM Starbook One
$ 2,730.00
Vixen
Apochromatic refractor AP 80/600 ED80Sf Advanced Polaris
$ 2,230.00
Vixen
Apochromatic refractor AP 103/825 ED AX103S OTA
$ 3,270.00
Skywatcher
Apochromatic refractor AP 62/400 Evolux-62ED Star Adventurer GTi Wi-Fi GoTo SET
RRP:
$ 1,520.00
Our price:
$ 1,420.00
Omegon
Apochromatic refractor Pro APO AP 140/910 Triplet ED FCD-100
$ 4,490.00
Omegon
Apochromatic refractor Pro APO AP 96/575 Triplet ED FCD-100
$ 1,490.00
Omegon
Apochromatic refractor Pro APO AP 106/700 Triplet ED FCD-100
$ 1,990.00
Sale price:
$ 1,607.00
Omegon
Apochromatic refractor Pro APO AP 85/510 Triplet ED FCD-100
RRP:
$ 1,199.00
Our price:
$ 949.00
William Optics
Apochromatic refractor Pleiades 181 AP 181/998 Astrograph OTA
$ 21,800.00
Omegon
Apochromatic refractor Pro APO AP 110/660 ED Carbon OTA
$ 1,790.00
ZWO
Apochromatic refractor FF130 AP 130/1000 Quadruplet OTA
$ 4,220.00
Omegon
Apochromatic refractor Pro APO AP 104/650 ED Triplet OTA
$ 3,190.00
OPT
Apochromatic refractor Radian AP 61/275 Raptor OTA
$ 2,280.00
Sale price:
$ 2,049.73
William Optics
Apochromatic refractor AP 156/1217 Fluorostar Red OTA
$ 10,300.00
William Optics
Apochromatic refractor AP 51/178 MiniCat WIFD OTA
$ 1,300.00
TeleVue
Apochromatic refractor AP 127/660 TVNP127is OTA
RRP:
$ 13,000.00
Our price:
$ 10,814.00
TeleVue
Apochromatic refractor AP 127/680 astrograph OTA
RRP:
$ 13,000.00
Our price:
$ 10,814.00
William Optics
Apochromatic refractor AP 71/350 RedCat 71 OTA
$ 2,280.00
William Optics
Apochromatic refractor AP 71/350 RedCat 71 WIFD OTA
$ 2,390.00
William Optics
Apochromatic refractor AP 61/360 ZenithStar ZS61 II OTA
$ 980.00
William Optics
Apochromatic refractor AP 61/360 ZenithStar ZS61 II OTA
$ 1,050.00
Sale price:
$ 940.41
William Optics
Apochromatic refractor AP Fluorostar 120/780 Gold OTA
$ 5,300.00
William Optics
Apochromatic refractor AP Fluorostar 120/780 Space Gray OTA
$ 5,300.00
William Optics
Apochromatic refractor AP Fluorostar 120/780 Red OTA
$ 5,300.00
Omegon
Apochromatic refractor Pro APO AP 80/500 ED Carbon OTA
$ 1,190.00
Sale price:
$ 899.00
Explore Scientific
Apochromatic refractor AP 165/1155 FPL-53 CF Feather Touch 3.0"
$ 10,900.00
William Optics
Apochromatic refractor AP 81/478 Gran Turismo 81 IV OTA
$ 2,170.00
Sale price:
$ 1,951.65
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.