Exp 12: image formation from spherical mirrors – PASCO OS-8500 INTRODUCTORY OPTICS SYSTEM User Manual
Page 66
Introductory Optics System
012-02744K
®
60
Exp 12: Image Formation from Spherical Mirrors
Focal Length
➀
60 mm
➁
Remove the viewing screen and focus an image of
the crossed arrow target on itself. In this position,
the focal length will be half of the distance be-
tween the target and the mirror. This method gives
a focal length of 49.5 mm
Magnification
f = -50
ho = 32
do (mm)
di
hi
1/di + 1/d
1/f
hi/ho
-di/do
% f
% m
500
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
450
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
400
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
350
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
300
-37
3.0
-0.02
-0.02
0.09
0.12
15.59%
-31.56%
250
-52
3.5
-0.02
-0.02
0.11
0.21
-31.31%
-90.17%
200
-46
4.5
-0.02
-0.02
0.14
0.23
-19.48%
-63.56%
150
-35
5.5
-0.02
-0.02
0.17
0.23
8.70%
-35.76%
100
-30
7.0
-0.02
-0.02
0.22
0.30
14.29%
-37.14%
75
-23
9.5
-0.03
-0.02
0.30
0.31
33.65%
-3.30%
50
-21
12.0
-0.03
-0.02
0.38
0.42
27.59%
-12.00%
f = 50
ho = 19
do (mm)
di
hi
1/di+1/do
1/f
hi/ho
-di/do
% f
% m
500
55
-2.0
0.02
0.02
-0.11
-0.11
0.90%
-4.50%
450
56
-2.5
0.02
0.02
-0.13
-0.12
0.40%
5.42%
400
57
-3.0
0.02
0.02
-0.16
-0.14
0.22%
9.75%
350
58
-3.5
0.02
0.02
-0.18
-0.17
0.49%
10.04%
300
60
-4.0
0.02
0.02
-0.21
-0.20
0.00%
5.00%
250
62
-4.5
0.02
0.02
-0.24
-0.25
0.64%
-4.71%
200
66
-6.0
0.02
0.02
-0.32
-0.33
0.75%
-4.50%
150
76
-10.0
0.02
0.02
-0.53
-0.51
-0.88%
3.73%
100
100
-19.0
0.02
0.02
-1.00
-1.00
0.00%
0.00%
Virtual Images
➤
➤
➤
➤
➤Note: It is difficult to accurately locate the
virtual images. Because of this difficulty, the
accuracy of the second part of this lab does not
compare to the accuracy of the first. In addition,
the image of the virtual image finder is too small
to use at longer distances, so only the shorter
ones should be used.
➤
➤
➤
➤
➤Note: The final two data points are not
available because the image is located on the
opposite side of the target from the mirror. In
other words, the view of the image is blocked by
the object.
➀
The results are in very good agreement with the
fundamental lens equation. The magnifications are
not as accurate, due to the difficulty in measuring
the size of the image accurately.