41. As opticians, they constructed the 76-cm refractor telescope at Nice Observatory, among others. 42. He brought with him an optical tube assembly for a 6-inch f / 15 refractor . 43. The hallmark of Holophane luminaires, or lighting fixtures, is the borosilicate glass reflector / refractor . 44. I want to know what type of telescope it is : refractor , reflector, or catadioptric. 45. The Standard Refractor was worth $ 100 when released, and the value increased to $ 125. 46. It is a refractor with double achromatic lenses of 40 cm diameter and has 5m focal length. 47. Another good choice for a beginner is an 80mm refractor , also on a German-equatorial mount. 48. The observatory now uses a refurbished 8-inch Reed refractor for visual observations of planets and stars. 49. Attached to the main telescope are two guide telescopes : an 18 cm and an 8 cm refractor . 50. The sub-telescope is a 15-cm apochromatic Kepler refractor of focal length 180-cm.
