Images Formed by Lenses

Images formed by Convex Lens

Position of object Position of image Nature of image
At infinityAt focusReal, diminished, inverted
At 2FAt 2FReal, diminished and inverted
Between 2F and FBeyond 2FReal, enlarged, inverted
At FNo imageRefracted rays are parallel
Between F and lensOn the same side as the objectVirtual, enlarged and upright

Uses of Convex Lens

  • Used in magnifying glass.
  • Used to correct the vision of long-sighted persons.

Images formed by Concave Lens

Position of object Position of image Nature of image
At infinityAt focusVirtual, diminished, upright
Between infinity and FBetween the object and the lensVirtual, diminished, upright

Uses of Concave Lens

  • Used in spy holes on doors to check the visitors.
  • Used to correct the vision of short-sighted persons.

Real Images

  • Real Image is an image which can be projected onto a screen.
  • Real images are always located in front of the mirror and behind the lens.
  • Real images are always inverted and never upright.
  • Concave lenses, Convex mirrors and plane mirrors always form virtual images and can never form real images.

Virtual Images

  • Virtual Image is an image which cannot be projected onto a screen.
  • Virtual images are always located in behind the mirror and in front of the lens.
  • Virtual images are always upright and never inverted.