Suppose I pass rays of already converging light through a concave lens. The rays are equally centered on the lens such that the original focal point is through the lens and centered on the lens axis.
My understanding is that the lens will bend the incoming rays, such that they all focus on a new focal point closer to the lens. Is there a formula I can use to determine the location of the new focal point, given the focal point of the lens and the original focal point?