Model No. OS-9498
Pinhole Viewer
4
®
Activity 1:
Examining the Relationship between Image Distance and
Object Distance
Note: This activity must be performed in a dark room.
Procedure
1.
Set up the apparatus as instructed in the "Equipment Setup" section.
2.
Turn on the incandescent bulb. Turn off the room lights.
3.
Using the metric scale on its side, adjust the inner tube so that the distance between the screen
and the foil is 4 cm. This length is referred to as the "image distance." (d
i
)
4.
Hold the Pinhole Viewer parallel to the tabletop. Observe the image of the bulb through the
Pinhole Viewer.
5.
Being careful not to change the image distance, move the Pinhole Viewer to a location where
the height of the bulb's image is the same as the height of the screen. Have a lab partner
measure the distance from the pinhole to the bulb. This length is referred to as the "object
distance." (d
o
) Record this value into the table.
6.
Repeat step 5 for image distances 8, 12, 16, and 20 cm. At each distance, measure the object
distance and record in the table.
Analysis
1.
From your data, explain the relationship between image distance and object distance.
2.
Draw a ray diagram to support your reasoning.
Equipment Required
Part Number
Pinhole Viewer assembled
OS-9498
Incandescent light bulb or equivalent
Ruler or measuring tape
Image Distance (cm)
Object Distance (cm)
4
8
12
16
20