• When?multiple lenses?are used in?series?(one after the other) this is called a?compound lens
• To find the?total power?of a compound lens, find the?sum of the powers?of the?individual lenses

PTotal?= P1?+ P2?+ .... Pn

• Where:
  • PTotal?= Total power of all the lenses (dioptre, D)
  • P1?= power of lens 1 (dioptre, D)
  • P2??= power of lens 2 (dioptre, D)

• In this case the image is:
  • Virtual
  • Diminished
  • Upright

• The lenses should be:
  • Arranged so that their principle axes line up
  • Touching or very close