Photo: A photographer with a portrait camera showing the object
(person sitting for the picture) and the inverted image on the
ground glass on the back of the camera.
Cameras are wonderful things, allowing us to "capture little
pieces of time". But how do they work? What happens when
you focus a camera? Your own eye acts somewhat like this camera.
Light that enters the lens of your eye is focused to produce an
image on the back of your eye, the retina. How are your eye and
a camera similar? How are they different?
Alternate Photo: Swimmers Snorkeling above a Coral Reef
These swimmers are enjoying the beauty of this coral reef. If they reach out to touch something, however, it may not be where it appears to be. Why do objects underwater appear to be closer to the observer than they really are?
You can observe this difference in apparent depth and actual depth yourself the next time you go snorkeling in a coral reef. Or the next time you look at your own toes in a swimming pool-or even in your own bathtub.
Mirrors and lenses change the way light travels and, thus, affect
the way we see things. If you look at a fish in a rectangular
aquarium you may see the fish in two quite different places as
you look from the front and then from the side. How can this be?
|Chapter 18 Mirrors and Lenses|
|18.1 Image in a Plane Mirror|
|18.2 Reflection from a Curved Mirror|
|18.3 Images Formed by Curved Mirrors|
|18.4 Apparent Depth|
|18.6 Images Formed by Lenses|
|18.8 End of Chapter Materials|