Celestron 102mm Omni XLT Refractor OTA - 21088-OTA

The Celestron Omni XLT 102 Refractor Telescope features an innovative design and high-quality optics, which combine to make it an excellent tool for astronomy and astrophotography. Its refractor telescope design makes it sturdy, easy to use, and easy to clean and care for. Additionally, this model features simple no-tool assembly.

Only the finest grade of glass is used in the Celestron Omni XLT's hand-selected and hand-figured mirrors and lenses. StarBright XLT multi-coatings and a generous 120mm objective lens allow for optimum light transmission. The 25mm eyepiece features 20mm eye relief, making it comfortable even for those who wear glasses.

High-Performance Features

• High quality optics start with each lens and(or) mirror being hand selected so only the finest grade of optical glass is used
• StarBright XLT coatings provide maximized light transmission
• 25 mm multi-coated eyepiece - 20 mm eye relief, 50° FOV
• 1.25" star diagonal

About Celestron Refractor Telescopes

Celestron’s high-quality refractor telescopes allow beginners to improve upon Galileo’s vision with a simple, reliable design that is easy to use, requires minimal maintenance, and is versatile enough for land or sky viewing. Known for viewing planetary detail and splitting close double-stars.

A refractor telescope uses a lens as the primary. The lens at the front of the telescope bends the light passing through it until it comes to a single point called the “focal plane”. The long, thin tubes of refractor telescopes look much the same as those Galileo used centuries ago. High-quality optical glass and multi-coatings provide today’s skywatchers views Galileo never dreamed of.

The refractor type of telescope is very popular with individuals who want mechanical simplicity, rugged reliability, and ease of use. Because the focal length is limited by the length of the tube, refractor telescopes become quite bulky and expensive beyond a four-inch aperture. This limits the light gathering properties of refractor telescopes, but it is an excellent choice for beginners and those who prefer simple operation and versatility. Refractor telescopes are also a popular choice because of their unobstructed view, high contrast and good definition.

Refractor Advantages

• Easy to set-up and use
• Simple and reliable design requires little or no maintenance
• Excellent for lunar, planetary and binary star observing especially in larger apertures
• Good for terrestrial viewing
• High contrast images with no secondary mirror or diagonal obstruction
• Color correction is good in achromatic designs and excellent in apochromatic and fluorite designs
• Sealed optical tube reduces image-degrading air currents and protects optics
• Objective lens is permanently mounted and aligned

Refractor Disadvantages

• More expensive per inch of aperture than Newtonians or Catadioptrics
• Heavier, longer and bulkier than equivalent aperture Newtonians and Catadioptrics
• The cost and size factors limit the practical maximum size primary to smaller apertures
• Some color aberration in achromatic designs (doublet)