Have a go: Ray Tracing

Ray Tracing Through a Thin Lens

This simulation demonstrates image formation by thin concave and convex lenses. We assume the thin lens equation. The lens is concave when the focal length is set negative and is positive when the focal length is set positive. The object distance and focal length of the lens can be changed by dragging the blue dots.

Try to answer the following:

  • For a concave lens, what object positions produce a real image?
  • Is it possible to produce a real image with a concave lens?