If two lenses have the same radii of curvature but different indexes

Click For Summary
SUMMARY

In the discussion, it is clarified that the focal length of lenses with identical radii of curvature but differing indices of refraction will not be equal. The lens with the higher index of refraction experiences greater refraction, resulting in a shorter focal length. This does not contradict the definition of focal length, which is applicable to mirrors, not lenses. The focal length of a lens is determined by the lens maker's equation, which incorporates the refractive index.

PREREQUISITES
  • Understanding of lens optics and refraction principles
  • Familiarity with the lens maker's equation
  • Knowledge of the concept of focal length
  • Basic principles of geometry related to curvature
NEXT STEPS
  • Study the lens maker's equation in detail
  • Explore the relationship between refractive index and focal length
  • Learn about the differences between lenses and mirrors in optics
  • Investigate practical applications of lenses in optical devices
USEFUL FOR

Students of optics, physics educators, and anyone interested in understanding the principles of lens design and behavior in optical systems.

needingtoknow
Messages
160
Reaction score
0

Homework Statement



If two lenses have the same radii of curvature but different indexes of refraction their focal lengths won't be equal because the one with the greater index of refraction will undergo greater refraction and will have a smaller f. Doesn't this contradict the definition of focal length which states that it has to be half of the radii of curvature?
 
Physics news on Phys.org
needingtoknow said:
Doesn't this contradict the definition of focal length which states that it has to be half of the radii of curvature?

No. This applies in case of a mirror not a lens .
 
My (admittedly rather dusty) memory does't have that kind of 'definition' for focal lenth at all. Who says such a thing ?
 

Similar threads

Replies
1
Views
2K
Replies
3
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 2 ·
Replies
2
Views
4K
  • · Replies 15 ·
Replies
15
Views
2K
  • · Replies 2 ·
Replies
2
Views
9K