Predicting Behaviours of Convex Lenses

Standard Ray 1

A ray of light parralel to the principle axis on the left will be refracted so it passes through the focal point on the right of the lens

Standard Ray 2

A ray passing through the entre of the lenses optical centre will emerge unrefracted therefore it will be undeviated

Standard Ray 3

A ray passing through the left focal point before passing through the lens would b refracted so it emerges parralel to the principle axis on the right of the lens

Real Image

Light rays come together to form an image. Where rays actually pass trough the image and can be projected and seen on a screen. Always inverted 

Virtual

Light rays don’t actually come together where the image appears. Where no rays actually pass through. It can’t be displayed on a screen. Eg. mirrors

Magnified

If image lager than object

Diminshed

If image smaller than object

Upright

If image is the same way up as the object

Invered

If the image is upside down

Real

If rays pass through the object

Virtual

If rays can only be seen to come form the object

Magnification =

Image height / actual height

Concave lenses are always

Virtual images