Download Convex Lens curves outward Light brought together magnifying glass

Light Notes 4
Lenses and Mirrors
Regular Reflection.
• Light waves hit a smooth surface and
bounce off (reflect) at the same angle
Angle of reflection
• Angle of incidence = _________________
sharp
• Gives ____________
image.
Diffuse Reflection
• When light waves hit a surface and
bounce off at different angles
• Angle of incidence __________________
= angle of reflection
• Gives _______
fuzzy image.
 Law of Reflection –
Angle of incidence = angle of reflection
Mirrors and Lenses
• Mirror – opaque material that reflects light
• Lens – transparent material that refracts
light
Concave and Convex Lenses
• Convex Lens
• curves outward
•Light brought together
• magnifying glass
Concave lens
 Curves inward
 light separated
 used in hotel peep holes
Concave Mirror
• has a reflecting surface that bulges inward (away from
the incident light). Concave mirrors reflect light inward to
one focal point, therefore they are used to focus light.
Unlike convex mirrors, concave mirrors show different
types of image depending on the distance between the
object and the mirror itself.
used in headlights of
vehicles to send parallel
rays to infinity , in
shaving mirror to get an
enlarged image of the
face and also by
dentists to see a bigger
image of the tooth / teeth
Convex Mirror
• The passenger-side mirror on a car is typically a convex mirror. In
some countries, these are labeled with the safety warning "Objects
in mirror are closer than they appear", to warn the driver of the
convex mirror's distorting effects on distance perception.
• Convex mirrors are used in some automated teller machines as a
simple and handy security feature, allowing the users to see what is
happening behind them. Similar devices are sold to be attached to
ordinary computer monitors.
curved mirror in which the
reflective surface bulges
toward the light source.
Convex mirrors reflect light
outwards, therefore they
are not used to focus light.
Mirrors VS Lenses
• Convex mirrors cause light to spread out, concave
mirrors cause light to go in and create a focal point. But
lenses work the opposite way: concave lenses spread
the light out, convex lenses focus the light. WHY IS
THAT? Why don’t they work in the SAME way as mirrors,
instead of the opposite way?
The reason that mirrors and lenses behave
so differently is that light passes though
lenses but bounces off mirrors.
Virtual Image
• What you see when you look in a mirror.
Real Image
• an image that can be projected onto a
screen