Thin convex lens.
A light bulb serves as an object for a convex lens. The relation between the object and image distance may be shown. One also shows that the image is real, inverted, and has a linear magnification of the image distance divided by the object distance, as long as the object distance is less than the focal length, there is no real image.
|Thin convex lens||017-9B or 017-13A|
|Screen (silk tablecloth)||021-7D|
|Stand for lens||021-20B|