Page 86 - Modern Optical Engineering The Design of Optical Systems
P. 86
Optical System Considerations 69
Eq. 4.6b ( ffd) f (f d)/f b
ab
b
20( 10 5)/( 10)
30
3 What powers are necessary in a two-component system if one requires a
20″ focal length, a 10″ back focus, and a 5″ air space?
ANSWER: Using Eqs. 4.7 and 4.8,
f df /(f ab B)
a
ab
5 20/(20 10)
10
d B/(f B d)
f b ab
5 10/(20 10 5)
10
