Page 49 - Modern Optical Engineering The Design of Optical Systems

32 Chapter Two

Bibliography

Bass, M., Handbook of Optics, Vol. 1, New York, McGraw-Hill, 1995.
Fischer, R. E., and B. Tadic-Galeb, Optical System Design, New York, McGraw-Hill, 2000.
Greivenkamp, J., Field Guide to Geometrical Optics, Bellingham, WA, SPIE, 2004.
Kingslake, R., Optical System Design, Orlando, Academic, 1983.
Smith, W. J., Modern Lens Design, New York, McGraw-Hill, 2002.
Smith, W. J., Practical Optical System Layout, New York, McGraw-Hill, 1997.

Exercises
1 A 10 in focal length lens forms an image of a telephone pole which is 200 ft
away (from its first principal point). Where is the image located (a) with
respect to the second focal point of the lens, and (b) with respect to the second
principal point?
2
2
ANSWER: (a) Using Eq. 2.3 x′ f /x 10 /( 200 12 10)
100/( 2390)
0.041841 in
(b) Using Eq. 2.5 s′ sf/(s f) 2400 10/( 2400 10)
24000/ 2390
10.041841 in

2 (a) How big is the image (in Exercise 1) if the telephone pole is 50-ft high?
and (b) what is the magnification?
ANSWER: (a) Solving Eq. 2.6 for h′, we get
h′ h x′/f 50 12 0.041841/10
2.510460 in
(b) Again using Eq. 2.6, we can get
m h′/h 2.510460/12 50
0.00418
or
(a) Solving Eq. 2.7a for m s′/s 10.041841/( 200 12)
0.004184
and h′ m h 0.004184 12 50
2.510460 in
3 A 1-in cube is 20 in away from the first principal point of a negative lens of
5 in focal length. Where is the image, and what are its dimensions (height,
width, thickness)?
ANSWER: Using Eq. 2.5 (or 2.4) we get s′ s f/(s f )
s′ 20( 5)/( 20 5) 4.0 in

The lateral magnification is thus m s′/s 4/( 20) 0.2 , and the longi-
—
tudinal magnification is approximately (by Eq. 2.9) m m 0.04 .
2
Thus, the height and width of the image are both 0.20 in, and the thickness
is ≈ 0.04 in.