Reason for f and R.

Asked by  | 23rd Jan, 2009, 03:40: PM

Expert Answer:

In case of a lens the focal length is given by the lens makers formula. The focal length depends on the material of the lens in addition to its R.

f is equal to R/2 only if the refractive index of the material is 1.5 and it is placed in air with n =1. Besides the radius of curvature of the two surfaces must be equal for this to happen.

Answered by  | 27th Jan, 2009, 04:12: PM

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