Teachers should also remember that magnifying glasses can be used to focus direct sunlight to produce intense heat that can burn skin and even ignite a fire. Window shades or blinds can be partially closed to keep direct sunlight out of the classroom during this activity. A sheet of unlined white paper should also be available for each student or activity group. Students with poor fine motor skills may have difficulty with holding a lens at the right distance to achieve focus. One of the most important parts of a camera is the lens.
Lenses are clear, rounded pieces of glass or plastic that bend light to form pictures.
Cameras that are used to make moves can use a variety of different lenses. Cinematographers must know how to pick the right lens to get just the effect they want when they shoot a scene. Different lenses are used for wide shots, medium shots, and close ups. This activity shows how geometry determines which lens does what. Cameras use a lens to collect light and make a picture on the surface of the film.