What Is IES Light Distribution Type I, Type II, Type III, Type IV, Type V？

The IES light distribution types are established by the Illuminating Engineering Society (IES), a professional organization that sets standards and guidelines for the lighting industry.

The IES develops and publishes these standards to ensure consistency and quality in designing and implementing lighting systems. These standards cover various aspects of lighting, including light distribution types, which specify how light should be distributed from luminaires to achieve desired lighting effects and performance characteristics in different applications.

The IES establishes and maintains the standards for light distribution types, which are widely used and referenced by lighting professionals, manufacturers, and designers globally.

Type I (Forward Throw Distribution):

lType I distribution produces a circular distribution of light.

lIt is suitable for illuminating walkways, paths, and small streets where the width of the road or area to be illuminated is approximately equal to the mounting height of the fixture.

Type II (Intermediate Distribution):

lType II distribution produces a rectangular distribution of light with a medium beam spread.

lIt is ideal for lighting wider pathways, larger streets, and parking lots where the width of the area is 1.75 times the mounting height.

Type III (Asymmetric Distribution):

lType III distribution emits light in a rectangular pattern with a wider forward throw than Type II.

lIt is suitable for roadways, general parking areas, and other areas where the width of the area to be illuminated is 2.75 times the mounting height.

Type IV (Asymmetric Distribution):

lType IV distribution emits a semicircular light pattern, ideal for mounting on the sides of buildings and walls, or for illuminating larger areas.

lIt has a wide lateral width and a narrow forward throw.

Type V (Symmetric Distribution):

lType V distribution emits light in a circular or symmetrical pattern.

lIt is used for general area lighting, especially where the area to be illuminated is large and uniform, such as parking lots, roadways, and general public areas.

BRIGHTLX team does well in designing LED lenses that can achieve various light distribution patterns such as Type I to Type V. We can customize the lens design according to the specific needs of customers, such as adjusting the beam angle, optimizing the beam uniformity, improving energy efficiency, etc. Flexibly respond to the changing needs of different LED OPTICS projects in the market, such as urban lighting, building facade lighting, industrial lighting and other application scenarios.