Conquest of Light is a 1975 short documentary directed and produced by Louis Marcus. It is an examination of the processes used to make Waterford crystal in Ireland. The clear crystal shapes of glass created by the craftsmen of Waterford are designed to capture the iridescence of light. From the intense heat of the furnace at the glass works in the Irish city of Waterford comes the crystal, blown by mouth and cut by hand, that is treasured over most of the world. The camera follows the liquid glass as it is blown into the shape of bowls, goblets, vases and many other forms, then cut and etched with great deftness and precision, producing the splendid examples of glass art for which the craftsmen at Waterford are famous. The film was nominated for an Oscar for Best Live Action Short Film. Preserved by the Academy Film Archive in 2011.

The movie is currently not available onine