Refracting telescope, Refracting telescope - Notable refracting telescopes, Refracting telescope - Technical difficulties, List of largest optical refracting telescopes, from which it is clear that their heyday was in the 19th century, Maksutov telescope
ARTICLES RELATED TO Refracting telescope - Technical difficulties
Refractors are criticized for their relatively high-degree of residual chromatic and spherical aberration. In very large apertures, there is also a problem of lens sagging, a result of gravity deforming glass. There is a further problem of glass defects, striae or small air bubbles trapped within the glass. In addition, glass is opaque to certain wavelengths, and even visible light is dimmed by reflection and absorption when it crosses the air-glass interfaces and passes through the glass itself. Most -or all- these problems are avoided by using r ...
Refractors are criticized for their relatively high-degree of residual chromatic and spherical aberration. This affects shorter focal lengths more than longer ones. A 4" F6 achromatic refractor is likely to show considerable color fringing. (generally a purple halo around bright objects) A 4" F16 will have little color fringing.
In very large apertures, there is also a problem of lens sagging, a result of gravity deforming glass. There is a further problem of glass defects, striae or small air bubbles trapped within the glass. In addi ...
The 50 cm refractor at Nice Observatory.
20 inch refractor at the Observatories at Chabot Space and Science Center in Oakland, California.
8 inch refractor at the Observatories at Chabot Space and Science Center in Oakland, California.
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