lens diagrams

• • a real image is an image that can be projected onto a screen
• • a virtual image when the light appears to be coming from behind the lens
• human eye or camera:

  • type of convex lens
  • for a distant object that is placed more than twice focal length from lens
  • the image is:
  • inverted
  • diminished
  • real
• projectors:

  • type of convex lens
  • for object placed between one and two focal lengths from lens
  • film must be loaded upside down so projected image is right way up
  • the image is:
  • inverted
  • magnified
  • real
• magnifying lens:

  • type of convex lens
  • when object placed at distance less than focal length
  • the image is:
  • upright
  • magnified
  • virtual
• concave lenses always produce images that are:

  • upright
  • diminished
  • virtual
• • an example where objects are seen through a concave lens is a peep hole lens
• • for an object viewed through a concave lens, light rays refracted and diverge on other side of lens
  • rays will appear from same side of principal axis so image will be upright
  • rays will appear further from principal axis, so image will be smaller than object