Convex Lenses

• What is a convex lens?

  A lens thicker at the center than edges
• What happens to light waves when they move from air to glass?

  They slow down and bend towards the normal
• What is the principal axis of a lens?

  The line passing through the center of the lens
• What is the symbol for principal focus?

  Capital F
• What is the focal length of a lens?

  The distance from the lens center to the focus
• What are the key features of a convex lens?

  • Thicker at the center than edges
  • Refracts light towards the normal
  • Has a principal focus and focal length
• How do you draw a ray diagram for an object more than two focal lengths away?

  Draw a line through the lens center and parallel to the axis
• What are the three key features of an image formed by a convex lens when the object is more than two focal lengths away?

  Image is diminished, inverted, and real
• What happens to the image when the object is between one and two focal lengths from the lens?

  The image is magnified, inverted, and real
• What are the properties of images formed by convex lenses based on object distance?

  • More than 2 focal lengths: diminished, inverted, real
  • Between 1 and 2 focal lengths: magnified, inverted, real