Educator

Images Formed by Lenses

• The main lens formula is

  1/f = 1/p + 1/q

• f is the focal length, + if the lens is convex (converging), - if the lens is concave (diverging).
• p is the distance of object to lens, + if object is real, - if object is virtual
• q is the distance of image to lens, + if image is real, - if image is virtual.