Meade Infinity 90 mm Alt-Azimuth Refractor Telescope for astronomy ,terrestrial
 
  WHY BUY A  REFRACTOR Under average seeing conditions, a useful rule of thumb in astronomy is that a good quality 3" to 4" refractor can often outperform an average quality 6" to 8" reflector or catadioptric telescope for seeing details on the Moon and planets, splitting binary stars, and resolving globular clusters.  Why? Unlike reflectors and catadioptrics (Schmidt-Cassegrains, Maksutov-Cassegrains, etc.), refractors do not have a secondary mirror obstruction or multiple-reflection optical path to introduce light-scattering diffraction and internal reflections that brighten the sky background, reduce contrast, and smear images.
For purely visual lunar, planetary, binary and star cluster observing, an altazimuth refractor with manual slow motion controls may be perfectly adequate. If a family shares the telescope, however, an equatorial mount with a motor drive will keep objects centered in the field of view so all can share the same view. Close-up lunar and planetary photography generally requires such a mount and motor drive. Thanks to the increasing availability of economically-priced high-sensitivity DSLR and CCD cameras for astrophotography, moderate-aperture short focal length refractors are becoming increasingly popular for wide-field deep space nebula and galaxy photography.   There are times when we wished to carry our scope to darker sites for great views on galaxies,star clusters,nebulas and we wished if we had portable scope with least weight and same time with decent aperture. well wait is over here. OVERVIEW Designed for beginners, the Infinity 90mm Alt-Azimuth Refractor Telescope from Meade is intended to introduce viewers to astronomy by giving them a complete set up for viewing the Moon, planets, meteor showers, and brighter deep-sky objects. Its manual alt-azimuth mount has an altitude lock and slow-motion controls for precise tracking of subjects. Three eyepieces provide 23x, 66.5x, and 95x magnifications with a 2x Barlow lens that doubles the magnification of each eyepiece for a wider-range of observing possibilities. An adjustable-height stainless steel tripod provides a stable platform for sky-watching, and the included 90° erect-image diagonal makes looking through the scope more comfortable, especially when aiming the telescope toward the zenith. The diagonal's prism corrects images horizontally and vertically, allowing the scope to be used for terrestrial viewing as well. An integrated dew-shield helps to prevent condensation on the objective lens, while blocking stray terrestrial peripheral light from interfering with celestial observations. Optical Performance  90mm aperture 600mm focal length f/6.7 focal ratio Integrated dew-shield Three Included Eyepieces  1.25" barrel diameter Fold down rubber eyecups Accepts standard filters and accessories Anti-reflection fully multicoated optics 26mm eyepiece yields 23x magnification 9mm eyepiece yields 66.5x magnification 6.3mm eyepiece yields 95x magnification Included Accessories  1.25" Rack-and-Pinion focuser 2x Barlow lens doubles the magnification of each eyepiece 90° erect-image prism corrects image horizontally and vertically Red dot finder with variable intensity Mount and Tripod  Manual Alt-Az mount Flex-arm controllers with large knurled knobs Stainless steel 2-stage tripod with accessory tray Adjustable height from 33" to 51" AutoStar Suite Astronomer Software  For Windows OS only Computer software helps users learn the night sky Displays more than 10,000 celestial objects including planets, stars    Optical Design   Refractor     Aperture   3.5" (90mm)     Focal Length   600 mm     Focal Ratio   f/6.7     Eyepiece Barrel Diameter   1.25"     Diagonal   90° erect-image diagonal     Finderscope   Red dot finder     Tripod   2-Stage stainless steel
  Minimum height: 33" (83.8 cm)
  Maximum height: 51" (129.5 cm)     Mount Type   Alt-Az     Optical Tube Dimensions   26.0 x 4.5" (66.0 x 11.4 cm)     Weight   OTA: 4 lb (1.8 kg)
  Tripod: 7.75 lb (3.5 kg)      Highest Useful Magnification 213 x Lowest Useful Magnification 13 x Limiting Stellar Magnitude 12.3 Resolution (Rayleigh) 1.55 arc seconds Resolution (Dawes) 1.29 arc seconds Light Gathering Power (Compared to human eye) 165 x Apparent Field of View 1 ° Linear Field of View (@1000 yds) 53 ft (16 m) Optical Coatings Multi Coated Optical Tube Length 36 in (914 mm)