What device is used to project solid images onto a surface for diagrams?

The opaque projector is specifically designed to project solid images directly onto a surface for the purpose of creating diagrams or presentations. It works by shining light onto an object, which could be a photograph, a printed image, or even a three-dimensional object, and then magnifying it to project a larger image onto a screen or wall. This ability to project actual objects or solid images makes it particularly useful in educational settings, such as cosmetology classes, where instructors can showcase techniques, styles, or products visually for better student understanding.

While other projectors, such as digital, slide, and LCD projectors, are used to present images or slides, they typically require a digital image input or prepared slides. In contrast, the opaque projector’s functionality allows for more spontaneous or diverse content projection directly from tangible objects, making it useful for in-class demonstrations or explaining complex concepts visually. Thus, its unique capability to handle solid images directly aligns with the requirements outlined in the question.