Distortion & Pincushion Setup
Pincushion Image

 

Code Number: 6A65.30

Demo Title: Distortion - Barrel and Pincushion

Condition: Good

Principle: Lens Distortions

Area of Study: Optics

Equipment:

Optics Table, Large Bell & Howell Lens (Serial Number 1729) Optical Object Lamps (2), Moiré' Arrays (Moiré' Array transparencies used with the optical object lamps).

Procedure:

Astigmatism and Distortion - Place the desired Moiré' Array design in the object lamp. Place the lamp on the optics rail at the end opposite the camera. Place the large Bell & Howell lens between the camera and the lamp. By moving the lens closer and farther away from the camera the 'pin cushion' and other effects can be demonstrated.

References:

  • O-370:  "Stops - Apertures & Obstacles",  DICK and RAE Physics Demo Notebook.
  • O-375:  "Thick Lens & Stop",  DICK and RAE Physics Demo Notebook.
  • John H. Moore, Christopher C. Davis, Michael A. Coplan,  "Distortion",  Building Scientific Apparatus 2nd Edition,  p. 147-148.
  • C. Harvey Palmer, "Experiment A13: The Off-Axis Aberrations of Lenses",  Optics - Experiments and Demonstrations, John Hopkins Press, 1962.