When using the lens equation, a negative value as the solution for di indicates that the image is

The Anatomy of a Lens

Refraction by Lenses

Image Formation Revisited

Converging Lenses - Ray Diagrams

Converging Lenses - Object-Image Relations

Diverging Lenses - Ray Diagrams

Diverging Lenses - Object-Image Relations

The Mathematics of Lenses

Ray diagrams can be used to determine the image location, size, orientation and type of image formed of objects when placed at a given location in front of a lens. The use of these diagrams was demonstrated earlier in Lesson 5 for both converging and diverging lenses. Ray diagrams provide useful information about object-image relationships, yet fail to provide the information in a quantitative form. While a ray diagram may help one determine the approximate location and size of the image, it will not provide numerical information about image distance and image size. To obtain this type of numerical information, it is necessary to use the Lens Equation and the Magnification Equation. The lens equation expresses the quantitative relationship between the object distance (do), the image distance (di), and the focal length (f)