Mammoth Memory

Concave lens – radius of curvature (`R`)

We should all know what a radius of a sphere is, so it should be easy to remember that:

The "radius of curvature" of a concave lens is the distance between the centre of curvature (`C`) and the curvature of sphere.

There are two radii of curvature for a concave lens, as below.

The positions of the radius of curvatures of a concave lens

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