SS: Ray Diagrams For Converging Lens

Trick to drawing ray diagrams for converging lens:

• There is one ray of light passing through the center of the lens. Always.
• 2 rays are enough to determine the position of image/object.
• The other ray of light ALWAYS passes through the focal point of the lens. Either the first focal point of the second focal point.
• If a ray passes through the focal point before passing through the lens, the refracted ray will be travelling parallel to principal axis.
• If a ray is parallel to principal axis before passing through the lens, the refracted ray will pass through the focal point.

Tips:

• Use solid lines for real light rays and put arrowheads to indicate direction
• Use dotted lines for extended light rays (virtual light rays) and do not add arrowhead
• Use solid lines for real images and dotted lines for virtual images

You can check the tricks above with the diagrams below. (Click to zoom)

Note:

• An image that is real is always inverted!
• An image that is virtual is always upright!