Ray Diagrams for Converging Lenses

Learning Goals

• Be able to draw ray diagrams for converging lenses.
• Be able to describe images produced by converging lenses.

Key Concepts

Locations of Object

• There are five different locations for the object relative to the lens:
  1. Beyond 2F'
  2. At 2F'
  3. Between 2F' and F'
  4. At F'
  5. Between F' and the lens

Grouping of Locations

• The first three locations (beyond 2F', at 2F', between 2F' and F') have the same rules for drawing the ray diagrams.

Rules for Drawing Ray Diagrams

1. Incident Light Ray Parallel to Principal Axis:
   • Refracts through the focus (F').
2. Light Ray through Optical Center:
   • Continues in the same direction (does not refract).

Example: Object Beyond 2F'

• Draw light rays according to the rules above.
• Where the rays cross determines the location of the image.
• Characteristics of the image:
  • Size: Smaller
  • Orientation: Inverted
  • Location: Between F' and 2F'
  • Type: Real (since it's on the opposite side of the lens from the object)

Special Case: Object at F'

• Result: No image is formed because the refracted rays are parallel and do not cross.
• Characteristics: No image generated.

Example: Object Between F' and Lens

• Same rules apply for light rays:
  1. Parallel light ray refracts through F.
  2. Light ray through the optical center continues straight.
• Characteristics of the image:
  • Size: Larger
  • Orientation: Upright
  • Location: On the same side of the lens as the object
  • Type: Virtual (since it's on the same side of the lens as the object)

Summary of Learning Goals

• Able to draw ray diagrams for converging lenses.
• Able to describe images produced by converging lenses.

Additional Notes

• If you have any trouble, review the video or ask the instructor for help.