1
Thin Lenses
Equipment List
Qty Items Part Numbers
1 Light Source OS-8470
1 Optics Bench OS-8518
1 Viewing Screen OS-8460
1 100 mm Convex Lens OS-8519
1 50 mm Convex Lens OS-8519
1 Vernier Caliper
Introduction
The purpose of this activity is to determine the relationship between object distance and image
distance for a thin convex lens. A thin lens is one whose thickness is
negligible in comparison to the image and object distance. A convex lens is
thicker in the center than at the edges and can also be called a positive lens or
converging lens. A concave lens is thinner at the center than at the edges and
can also be called a negative lens or a diverging lens. Use a light source,
optics bench, lens, and viewing screen to measure object distance, image
distance and size. The technological pieces of equipment pictured here make
use of lenses.
Background
When a light source, like a light bulb shine, it radiates light in all directions.
A lens will alter the direction of those rays of light which strike it, resulting
in either a real or virtual image to be formed. If the rays of light go from the
source through the lens to form a single point in space, it will form a real
image. However, a virtual image is formed if the projections from the rays of
light form on the same side as the source. These can be seen in Figure 1 and
Figure 2.
Fig. 1: Real Image Formation
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Fig. 2: Virtual Image Formation
rev 08/2019
