Maths, Physics Revision
Physics A Level Physics Home Revision hut
Ray Diagrams
The red rays are VIRTUAL
rays and are the real rays
extended backwards
An inverted, diminished,
real Image is produced
An inverted, magnified,
real image is produced
The next section deals with reflection
In curved mirrors
In Fig 2 the
object is 
between F and
2F. The image
 Is further 
and real
It is possible to predict the size and position of of an
image in a convex lens by constructing  an accurate ray
In Fig 1 the object is at 2F. The image is at 2F on the 
other side,same size as the image, inverted, same distance 
away and real.
Play the diagrams
Fig. 1
Fig. 2
In Fig.3 the 
object is beyond
2F. The image is 
inverted and real
Fig 3
In Fig 4 the 
image is between
F and the lens. 
This time the rays 
will not meet 
behind the lens so
they have to be 
extended back in
front of the lens
(same side as the 
object). They meet 
and produce a
magnified, upright,
virtual image.

A real image is on the opposite side of the lens to the object
and can be projected onto a screen and is formed by real
A virtual image is on the same side as the object and cannot
be projected. Virtual images are formed by virtual rays
Concave mirror