Refractor telescopes (also known as dioptrics) are probably what most of us think of when we hear the word "telescope." Refractors have a long, thin tube in which light passes in a straight line from the front objective lens directly to the eyepiece, at the opposite end of the tube.
• Simplicity of design, which translates into reliability and ease of use
• Little or no maintenance requirements
• Excellent lunar, planetary and binary star viewing.
• High contrast images with no secondary mirror or diagonal obstruction.
• Sealed optical tube, to protect the optics and reduce air currents, which tend to degrade image quality.
• Permanently mounted and aligned objective lens.
FirstScope 70 models are powerful optical instruments that have 100 times the light gathering ability of the naked eye. This abilityallows the FirstScope 70 to deliver images 37% brighter than those produced by a 60mm refractor telescope. The objective lens is designed to yield the finest images available in this class of optical instrument. The accessories are all made of glass with metal construction, to ensure good image quality
Has all glass components, coated optic's and smooth functioning mounts, with the added benefit of slow motion controls on the mount for easy adjustments. The Firstscope 70 telescope tube is glossy black aluminum
While observing, you'll notice that as the earth rotates on its axis, stationary stars appear to move across the sky. Thus, due to the earth's rotation, the object you're viewing will float out of view in both axes, over time. A telescope on an equatorial mount can be aimed at a celestial object and guided with the slow motion controls to follow the object across the sky and keep it in the field of view of your telescope.
|Optical tube||70mm (2.8") diameter Refractor|
|Focal Length / F#||900mm F/13|
|Eyepiece||20mm Kellner (45x)
10mm Kellner (90x)
|CD ROM||The Sky Level 1|
|Highest Useful Magnification||165x|
|Limiting Stellar Magnitude||11.7|
|Resolution: Rayleigh||1.98arc seconds|
|Dawes Limit||1.66 arc seconds|
|Photographic Resolution||141 lines/mm|
|Light Gathering Power||100x unaided eye|
|Field of View: standard eyepiece||1.1°|
|Linear FOV (@1000 yds)||58 ft|
|Optical Tube Length||30 inches|
|Telescope Weight||17 lbs|