Donuts help sharpen gobo projections by reducing the diameter of the output lenses. The smaller the aperture the sharper the image, however less brightness.
Apollo ThinLine™ Donuts are unique to the market by the material used in their construction – aluminum vs. steel. ThinLine™ donuts are much lighter than traditional steel donuts – and three times less expensive. All donuts are manufactured of .009" black, non-reflective, coated high-temperature aluminum.