Optics
The Physics Of Optical Communication
Lenses and Ray Tracing
Ray tracing involves tracking certain easy to follow rays through the lens. With convex lenses, these are
A horizontal ray is refracted through the far focal point.
A ray that strikes the middle of the lens, continues straight.
A ray that seems to have come from the focal point, will leave the lens horizontal. (Ray 3 is not always needed or used)
Lesson 1 deals with a convex lens with an object far from the lens.
Lesson 2 deals with a convex lens with an object near the lens.
Try it yourself!
Now try tracing the image of an arrow that is placed in the following positions:
(similar to the diagram below)
Much greater than 2 focal lengths distance from the lens
2 focal lengths distance from the lens
between 1 and 2 focal lengths distance from the lens
1 focal length distance from the lens
less than a focal length from the lens.