What is a thin lens ?
A lens is made of a transparent material (glass or plastic)
A lens always has two sides, with at least one of them that is not flat.
Lenses are present in most of optical devices such as telescopes,
microscopes, camera lenses, binoculars etc..
are called "thin"
when their thickness is much less
than their diameter.
Differences between converging and diverging lenses
two kind of lenses: converging lenses and diverging lenses.
- A converging lens is wider at its middle than at its edges: it is
- A diverging lens is thinner at its middle than at its edges: it is
3) Characteristics of converging
and diverging lenses
owns an axis of symetry called principal axis.
point that belongs to the principal axis and to the center of the lens
is denoted by O and called optical center.