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.
Skywatcher
Apochromatic refractor AP 72/420 EvoStar 72 ED DS Pro OTA
$ 465.00
Omegon
Apochromatic refractor Apochromatischer Refraktor Pro APO AP 30/135 OTA
RRP:
$ 439.00
Our price:
$ 395.00
Skywatcher
Apochromatic refractor AP 80/600 EvoStar ED OTA
$ 830.00
Skywatcher
Apochromatic refractor AP 100/550 ESPRIT-100ED Professional OTA
$ 2,510.00
TS Optics
Apochromatic refractor AP 80/480 ED Triplet Photoline OTA
RRP:
$ 1,050.00
Our price:
$ 680.00
William Optics
Apochromatic refractor AP 51/250 RedCat WIFD OTA
$ 1,150.00
TS Optics
Apochromatic refractor AP 60/360 ED TSMPT60 OTA
RRP:
$ 417.00
Our price:
$ 375.00
APM
Apochromatic refractor AP 140/980 SD OTA
RRP:
$ 3,540.00
Our price:
$ 3,120.00
Skywatcher
Apochromatic refractor AP 150/1200 EvoStar ED EQ6R GoTo
RRP:
$ 4,700.00
Our price:
$ 4,380.00
Omegon
Apochromatic refractor Pro APO 85/560 ED Triplet CEM26 LiteRoc
RRP:
$ 3,908.00
Our price:
$ 3,890.00
Askar
Apochromatic refractor Apochromatischer Refraktor AP 40/180 FMA180PRO OTA
$ 550.00
William Optics
Apochromatic refractor AP 71/350 RedCat 71 WIFD OTA
$ 2,290.00
Omegon
Apochromatic refractor Pro APO 94/517 Triplet ED CEM26 LiteRoc
RRP:
$ 3,548.00
Our price:
$ 3,490.00
William Optics
Apochromatic refractor AP 156/1217 Fluorostar Gray OTA
$ 9,800.00
Explore Scientific
Apochromatic refractor AP 80/480 ED Alu iEXOS-100 PMC-8 Wi-Fi GoTo
RRP:
$ 1,690.00
Our price:
$ 1,360.00
TS Optics
Apochromatic refractor AP 72/432 FPL53 Photoline OTA
$ 630.00
William Optics
Apochromatic refractor AP 51/178 MiniCat WIFD OTA
$ 1,250.00
William Optics
Apochromatic refractor AP 71/350 RedCat 71 OTA
$ 2,190.00
William Optics
Apochromatic refractor AP 71/420 Gran Turismo GT 71 OTA
$ 1,250.00
Skywatcher
Apochromatic refractor AP 62/400 Evolux-62ED Star Adventurer GTi Wi-Fi GoTo SET
RRP:
$ 1,560.00
Our price:
$ 1,460.00
TS Optics
Apochromatic refractor AP 60/360 PhotoLine FPL53 Red OTA
RRP:
$ 630.00
Our price:
$ 490.00
William Optics
Apochromatic refractor AP 81/478 Gran Turismo 81 IV OTA
RRP:
$ 2,080.00
Our price:
$ 1,990.00
Askar
Apochromatic refractor Apochromatischer Refraktor AP 40/180 FMA180 OTA
$ 444.00
Omegon
Apochromatic refractor Apochromatischer Refraktor Pro APO AP 108/600 Quintuplet OTA
RRP:
$ 3,090.00
Our price:
$ 2,899.00
Vixen
Apochromatic refractor AP 103/825 ED AX103S Sphinx SXP2 Starbook Ten GoTo
$ 9,400.00
Explore Scientific
Apochromatic refractor AP 102/714 ED FCD-100 CF Hexafoc iEXOS-100 PMC-8 Wi-Fi GoTo
RRP:
$ 2,960.00
Our price:
$ 2,660.00
Tecnosky
Apochromatic refractor AP 70/420 ED V2 OTA
$ 417.00
Vixen
Apochromatic refractor AP 80/600 ED80Sf Advanced Polaris
$ 2,130.00
Vixen
Apochromatic refractor AP 115/890 SD115S Sphinx SXP2 Starbook Ten GoTo
$ 8,600.00
Skywatcher
Apochromatic refractor AP 82/530 Evolux-82ED OTA
$ 780.00
Askar
Apochromatic refractor Apochromatischer Refraktor AP 71/490 Flat-Field 71F OTA
$ 840.00
Askar
Apochromatic refractor Apochromatischer Refraktor AP 72/400 FRA400 OTA
$ 1,410.00
William Optics
Apochromatic refractor AP 156/1217 Fluorostar Red OTA
$ 9,800.00
Omegon
Apochromatic refractor Pro APO AP 85/510 Triplet ED FCD-100
RRP:
$ 1,199.00
Our price:
$ 949.00
TS Optics
Apochromatic refractor AP 102/714 Photoline OTA
RRP:
$ 1,200.00
Our price:
$ 1,050.00
Omegon
Apochromatic refractor Pro APO AP 66/400 ED SkyGuider Pro
RRP:
$ 1,735.00
Our price:
$ 1,650.00
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.