Identify the positive and negative lenses from the illustration below:
Positive lenses _______, ______.
Negative Lenses ______, ______.
FOCAL PLANE AND FOCAL LENGTH
a. When a lens projects an image, the plane in which the image is sharply
formed is called the focal plane.
when the lens is focused at infinity, is called focal length.
can be changed in some modern lenses by increasing or decreasing the distance
between the front and rear lens elements.