In this guided inquiry two part PhET lab your students will investigate how an image is formed by four different optical instruments: a convex lens, a concave lens, a convex mirror and a concave mirror. In Part 1 students will investigate (1) how the characteristics of the image change as the object is brought closer to each of the lenses and mirrors, (2) the similarities and differences in image formation for each of the lenses and mirrors and (3) the meaning of the points F and 2F for the conv