Lightbox

Lightbox is a general term for devices and interface patterns that illuminate a translucent panel from behind. It is used in photography, advertising, medicine, and digital user interfaces to reveal detail, create visual emphasis, or display content prominently.

In photography and graphic arts, a traditional lightbox is a shallow box with an evenly diffused light source behind a translucent sheet. It allows viewing, tracing, or color matching on film negatives, slides, or drawings. Modern versions typically use LEDs and diffusers, and may be portable or wall-mounted.

In signage and retail, a lightbox is a backlit cabinet with a graphic panel. Light sources behind the panel illuminate the artwork, producing bright, uniform signage that is visible in daylight or darkness. Contemporary units often use LEDs and are designed for easy panel replacement.

In medical imaging, a viewbox or lightbox is a flat, backlit surface used to display radiographs and slides. It provides consistent illumination to maximize contrast and detail, aiding interpretation by clinicians.

In web and application design, a lightbox is a modal overlay that dims the background to spotlight content such as an image, video, or confirmation dialog. It prevents leaving the current page while presenting a focused view.

Common materials include acrylic, tempered glass, or polycarbonate fronts with aluminum or plastic enclosures. When using older fixtures with fluorescent lamps, overheating can occur; LED variants are more energy-efficient and produce less heat.