Click and drag
to change
the values of
applet parameters.
If we trace rays from the top of the smiling face to the back of the dark box, we can see that they only fall at one place. Similarly if we trace light from the bottom of the smiling face to the black room, than we see that rays only fall on one point. The same fact is true for all points on the smiling face. This means that there will be light in the dark box coming from an outside source through a small hole, and it will be in the same shape as the object outside the box from which the light is coming.
Notice that if the hole in the camera obscura is large,
light
coming from the top of the smiling face will fall in a small area, and
not in one point. In a way there will be many images of the smiling
face on the back of the box, all slightly shifted around, which means the
final image will be blurry.
