PASCO OS-9498 User manual

Instruction Manual
No. 012-08952A
Pinhole Viewer
OS-9498
Instructions
Experiments

Pinhole Viewer Model No. OS-9498
Table of Contents
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Equipment Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Activity 1:
Examining the Relationship between Image Distance and Object Distance . . . . . . . . . . . 4
Activity 2:
Examining the Relationship between Pinhole Size and Image Focus. . . . . . . . . . . . . . . . . 5
Activity 3:
Examining the Relationship between the Number of Pinholes and the Image. . . . . . . . . . 6
Activity 4:
Verifying the Magnification Equation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Activity 5:
The Purpose of a Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Activity 6:
The Purpose of a Pinhole. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Safety. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Technical Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Copyright and Warranty Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Model No. OS-9498 Pinhole Viewer
1
®
Pinhole Viewer
Model No. OS-9498
Included Equipment Replacement Part Number
1. Outer tube, 37 cm long X 11 cm diameter (4) part of assembly 003-08951
2. Inner tube with translucent screen (4) part of assembly 003-08951
3. Foil circle (100) 003-08928
4. O-ring (20) 638-027
Additional Equipment Required Model Number
Dark room
Incandescent light bulb (or equivalent)
Ruler or measuring tape
Small pin
3
4
2
1

Pinhole Viewer Introduction
2
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Introduction
The Pinhole Viewer can be used for studying optical principles such as the:
- Magnification equation
- Relationship between image distance and object distance
- Pinhole size and image focus
- Number of pinholes and image quality
To study these relationships, students point the Pinhole Viewer toward a luminous or highly
illuminated object. An image of the object appears on the translucent screen. A convenient metric
scale on the outside of the inner tube makes for easy reading of the image distance.
Equipment Setup
1. Carefully place the foil disc on one end of the outer tube.
2. Roll an O-ring over the foil disc to hold it in place. Be sure to smooth out
any wrinkles in the foil.

Model No. OS-9498 Equipment Setup
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3. Using a pin, make a hole in the center of the foil.
4. Insert the screen-end of the inner tube into the open
end of the outer tube until the metric scale reads 5
cm.
5. Point the Pinhole Viewer at the desired object.
6. Look through the open end to observe the image.
7. Slide the inner tube back and forth to change the distance between the pinhole and the screen
(di).

Model No. OS-9498 Pinhole Viewer
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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." (di)
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." (do) 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

Model No. OS-9498 Pinhole Viewer
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Activity 2:
Examining the Relationship between Pinhole Size and Image
Focus
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. Hold the Pinhole Viewer parallel to the tabletop. Observe the image of the bulb through the
Pinhole Viewer. Notice the quality of the image. In the table, record the focus level for the
small pinhole size. Use the following scale to determine the image quality: 1 = very blurry
(no discernible shape), 3 = some blur (can see lines and circle, but appear fuzzy), and 5 =
excellent focus (lines very clear and good contrast).
4. With a push pin, triple the size of the pinhole. Record the focus level for the medium pinhole
size. Keep the Viewer the same distance from the bulb as in step 3.
5. Increase the pinhole to the size of a pencil. Record the focus level for the large pinhole size.
Keep the Viewer the same distance from the bulb for each measurement.
Analysis
1. Describe the relationship between pinhole size and image quality (focus level).
2. Draw a ray diagram for each pinhole size to support your reasoning.
Equipment Required Part Number
Pinhole Viewer assembled OS-9498
Incandescent light bulb or equivalent
Push-pin
Pinhole Size Focus Level (1-3)
Small
Medium
Large

Model No. OS-9498 Pinhole Viewer
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Activity 3:
Examining the Relationship between the Number of Pinholes
and the Image
Note: This activity must be performed in a dark room.
Procedure
1. With the exception of the pinhole in the center, set up the apparatus as instructed in the
"Equipment Setup" section.
2. Place four very small pinholes on the foil in the shape of a 1-inch square.
3. Turn on the incandescent bulb. Turn off the room lights.
4. Hold the Pinhole Viewer parallel to the tabletop.
5. Observe the image on the screen and record your observations.
6. Rotate the Screen counterclockwise and describe any changes to the image on the screen.
7. Rotate the pinholes counterclockwise by turning the outer tube. Describe any changes to the
images.
Analysis
1. Explain the effect of multiple pinholes.
2. Draw a ray diagram to support your reasoning.
Equipment Required Part Number
Pinhole Viewer assembled OS-9498
Incandescent light bulb or equivalent
Push-pin

Model No. OS-9498 Pinhole Viewer
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Activity 4:
Verifying the Magnification Equation
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. Hold the Pinhole Viewer parallel to the tabletop. Observe the image of the bulb through the
Pinhole Viewer.
4. Adjust the scale on the side of the inner tube to 6.0 cm (image distance, di). Observe the bulb
through the 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.
6. Have a lab partner measure the distance from the pinhole to the bulb (object distance, do).
7. Measure the object size (o), height of the bulb, and the image size (i), height of the image.
Record the values in the table.
8. Repeat step 4-7 for images distances of 8.0, 10.0, 12.0, 14.0, 16.0, 18.0 and 20.0 cm.
9. Calculate i/o and di/dofor each of your trials.
Equipment Required Part Number
Pinhole Viewer assembled OS-9498
Incandescent light bulb or equivalent
Ruler or measuring tape
Image
Distance (di)Object
Distance (do)Object Size (o) Image Size (i) i/o di/do
6.0 cm
8.0 cm
10.0 cm
12.0 cm
14.0 cm

Pinhole Viewer Verifying the Magnification Equation
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Analysis
1. Look at the i/o and di/docolumns in the upper data table. What pattern do you notice?
2. Draw ray diagrams with i, o, di, and doappropriately labeled for the 6.0 cm image distance
and the 20.0 cm image distance.
3. Using the two ray diagrams from the previous question, explain why the pattern in the i/o and
the di/docolumns exists.
16.0 cm
18.0 cm
20.0 cm
Image
Distance (di)Object
Distance (do)Object Size (o) Image Size (i) i/o di/do

Model No. OS-9498 Pinhole Viewer
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Activity 5:
The Purpose of a Screen
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. Hold the Pinhole Viewer parallel to the
tabletop. Observe the image of the bulb
through the Pinole Viewer.
4. Remove the outer tube and observe the image
without the pinhole. Record your
observations.
Analysis
1. Explain the effect of multiple pinholes.
2. Draw a ray diagram to support your reasoning.
Equipment Required Part Number
Pinhole Viewer assembled OS-9498
Incandescent light bulb or equivalent

Model No. OS-9498 Pinhole Viewer
10
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Activity 6:
The Purpose of a Pinhole
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. Hold the Pinhole Viewer parallel to the
tabletop. Observe the image of the bulb
through the Pinole Viewer.
4. Remove the inner tube and observe the image
without the screen. Record your
observations.
Analysis
1. Explain the effect of removing the screen.
2. Draw a ray diagram to support your reasoning.
Equipment Required Part Number
Pinhole Viewer assembled OS-9498
Incandescent light bulb or equivalent

Model No. OS-9498 Pinhole Viewer
Safety
Read the instructions before using this
product. Students should be supervised by
their instructors. When using this product,
follow the instructions in this manual and all
local safety guidelines that apply to you.
Technical Support
For assistance with any PASCO product,
contact PASCO at:
Copyright and Warranty
Information
Copyright Notice
The PASCO scientific 012-08952A Pinhole
Viewer Instruction Manual is copyrighted
and all rights reserved. However, permission
is granted to non-profit educational
institutions for reproduction of any part of
this manual, providing the reproductions are
used only for their laboratories and are not
sold for profit. Reproduction under any other
circumstances, without the written consent
of PASCO scientific, is prohibited.
Limited Warranty
For a description of the product warranty, see
the PASCO catalog.
Address: PASCO scientific
10101 Foothills Blvd.
Roseville, CA 95747-7100
Phone: [phone]
[phone]
Fax: [phone]
Web: www.pasco.com
Email: [email protected]