How lenses work

• What happens to light waves as they pass through a lens

  They are refracted (change direction)
• What is the focal length of a lens

  The distance between the principle focus and the centre of the lens
• What are 2 differences between high and low power lenses

  High power lenses are more curved

  High power lenses are made from a material that refracts light more strongly
• Three things to remember when describing an image

  Is it real?

  Is it upright or inverted?

  Is it bigger or smaller than the object?
• How can you tell the difference between a real and virtual image?

  A real image is formed where the light rays comes together and can be captured on a screen
• What type of images can be produced by a convex lens

  Real or virtual images
• What types of images can be produced by concave lens

  Always virtual