- #1

Snoopey

- 6

- 0

Hi all,

I'm looking for an equation which will give me the focal length of a biconvex lens given that we know both Radii of curvature, the thickness of the lens and the refractive index inside and outside.

An equation is given on wikipedia here http://en.wikipedia.org/wiki/Focal_length as

I need something I can reference though and I can't see this equation anywhere else I look. Also I need a more general version of the equation which involves the refractive index of the substance surrounding the lens.

Could anyone point me to a derivation of this formula or lead me in the right direction?

I also need to find a legitimate source for the back focal distance shown on the same page of wikipedia:

Thanks all!

EDIT: Found what I was looking for, just needed a bit more snooping!

http://physics.tamuk.edu/~suson/html/4323/thick.html

I'm looking for an equation which will give me the focal length of a biconvex lens given that we know both Radii of curvature, the thickness of the lens and the refractive index inside and outside.

An equation is given on wikipedia here http://en.wikipedia.org/wiki/Focal_length as

I need something I can reference though and I can't see this equation anywhere else I look. Also I need a more general version of the equation which involves the refractive index of the substance surrounding the lens.

Could anyone point me to a derivation of this formula or lead me in the right direction?

I also need to find a legitimate source for the back focal distance shown on the same page of wikipedia:

Thanks all!

EDIT: Found what I was looking for, just needed a bit more snooping!

http://physics.tamuk.edu/~suson/html/4323/thick.html

Last edited: