Keplarian Telescope Setup
Galilean Telescope Setup

 

Code Number: 6A70.20

Demo Title: Telescopes - Optical Rail Models

Condition: Good

Principle: Lens Systems and Focal Lengths

Area of Study: Optics

Equipment:

Optics rail, video camera, meter stick, #5 poster, 76 cm FL lens, 20 cm FL lens, minus 20 cm FL lens.

Procedure:

Place the #5 poster on the far wall of the lecture room.  Without looking through the lenses point the camera at the #5 and focus.  Place the +20 and +76 lens on the indicated places on the rail and point the system toward the #5.  The field of view here should be large but the #5 will be upside down (this is what we refer to as a Keplerian telescope).

Now replace the +20 lens with the - 20 lens and move the lenses to the new positions.  Now observe that the field of view is very narrow but the #5 is right side up (this is what we refer to as a Galilean telescope setup).

References:

  • Christopher Sirola, "Galileo’s Telescope", TPT, Vol. 57, #1, Jan. 2019, p. 56.
  • Max Ziegler, "Galilean Refractor in an Aquarium", TPT, Vol. 50, #4, Apr. 2012, p. 251.
  • Maurizio Vannoni, Giuseooe Molesini, Andrea Sordini, and Samuele Straulino, "A Mechanical Analogue of the Refracting Telescope", TPT, Vol. 49, #4, Apr. 2011, p. 236.
  • A.J. Cox and Alan J. DeWeerd, "The Image Between the Lenses: Activities with a Telescope and a Microscope", TPT, Vol. 41, #3, Mar. 2003, p. 176.
  • Gene Byrd and Mark Graham, "Camera and Telescope Free-for-All!", TPT, Vol. 37, #9, Dec. 1999, p. 547.
  • Mark L. Biermann and Lois A. A. Biermann, "When the f / # is Not the f / #", TPT, Vol. 34, #5, May 1996, p. 312.
  • Robert P. Lanni, "Optics Experiments by Armstrong", TPT, Vol. 5, #2, Feb. 1967, p. 84.
  • H. L. Armstrong, "An Experiment on Optical Devices", TPT, Vol. 4, #7, Oct. 1966, p. 323.
  • Rick Beyer, "Lippershey's Looker", The Greatest Science Stories Never Told, p. 14.
  • John H. Moore, Christopher C. Davis, and Michael A. Coplan, "Lenses and Lens Systems", Building Scientific Apparatus 2nd Edition, p. 143 - 144.
  • Raymond Bruman, "Lens Table", Exploratorium Cookbook I, p. 11.1 - 11.4.
  • Gordon McComb, "Laser Optics Experiments",  Lasers, Ray Guns, & Light Cannons, p. 133.
  • Bobby Mercer, "Star Gazer", Junk Drawer Physics, p. 96.
  • C. Harvey Palmer, "Experiment A15: The Telephoto Lens, The Galilean Telescope, and the Barlow Lens", Optics - Experiments and Demonstrations, John Hopkins Press, 1962.
  • C. Harvey Palmer, "Experiment A16: The Refracting Telescope", Optics - Experiments and Demonstrations, John Hopkins Press, 1962.
  • "8. The Galilean Telescope", Experiments in Optics, Part 1, J. Klinger Scientific Apparatus Corp., Bulletin 101.
  • "7, The Astronomical Telescope", Experiments in Optics, Part 1, J. Klinger Scientific Apparatus Corp., Bulletin 101.
  • T. D. Rossing and C. J. Chiaverina, "4.10, Telescopes and Microscopes", Light Science, Physics and Visual Arts, p. 95.
  • "Magnifying Power and Resolving Power of a Telescope", Selective Experiments in Physics, CENCO, 1962.
  • "Simple Telescopes - Magnifying Power", Selective Experiments in Physics, CENCO, 1962.
University of Maryland Physics Department QOTW Question #124
University of Maryland Physics Department QOTW Answer #124