Identify the optical system of an overhead projector? ?

The optical system of an overhead projector typically consists of a light source (such as a halogen lamp), a condenser lens to focus the light, a transparency film holder, a mirror or prism to redirect the light towards the projection lens, and a projection lens to focus the image onto a screen or surface.

- Light source: A high-intensity lamp, typically a halogen or metal-halide lamp, provides the light for the overhead projector.
- Condenser: A lens or system of lenses that concentrates the light from the lamp onto the transparency.
- Transparency: A clear or semi-transparent sheet of material, such as acetate or plastic, on which the image to be projected is printed or drawn.
- Projection lens: A lens or system of lenses that projects the image from the transparency onto the screen.
- Screen: A white or light-colored surface on which the projected image is displayed.