A refractor uses a convex lens as the obective to gather, bend and focus light at the eye piece. Various configurations of refractor design attempt to correct image orientation and colour errors but the basic principle remains the same.

Achromatic refractors overcome the need for long focal lengths inherent in refractor design by combining two glass elements to form the objective, these double elements bring two wavelengths of light, usually red and blue, to focus at the same point.

Apochromatic refractors have objectives made from special glass designed to bring three wavelengths of light, usually red, blue and green, to focus at the same point. Apochromatic or Apos as they are known, produce very sharp images almost totally free from colour error, but at a price.

Featured Telescope - Celestron NextStar 102 SLT
As a beginners telescope we would recommend the Celestron NextStar 102 SLT Computerised scope.

NexStar 102SLT - General Features;
  • High quality 102mm refractor
  • Fully computerized altazimuth mount
  • StarPointer finderscope to help with alignment
  • Accurate locating and tracking
  • Quick-release fork arm mount
  • Optical tube and accessory tray
  • Quick no tool set up
  • Sturdy stainless steel tripod
  • Accessory tray included
  • Good for terrestrial and celestial observing
  • Includes NSOL telescope control software for basic control of your telescope via computer (with optional RS-232 cable)

  • PLUS FREE delivery in the UK!

If you own a NextStar 102 or another type of refractor please consider leaving a comment below to help first time buyers decide. What do you like/dislike about them? Do you find them easy to use?

Posted by Telescope Sale Team
On 5th April 2011