What does a projection lens do?

A projection lens is designed to focus and enlarge an image from a light source, such as a slide or film, onto a flat surface like a screen or wall. It plays a crucial role in projectors by ensuring that the image maintains clarity and sharpness at varying distances. The lens shapes the light path, allowing for adjustments in size and focus, which enhances the overall viewing experience. Additionally, projection lenses can vary in design to accommodate different types of projectors and specific applications.