Uplight

The IESNA classifications below (RP-33 and RP-8) describe uplight control for a luminaire’s distribution. In order for the classification to be valid in actual practice, it is essential that the luminaire is not uptilted during installation.

  1. Full Cutoff

    2. A luminaire light distribution where zero candela intensity occurs at an angle of 90°, and at all greater angles.

    Full Cutoff is the most extreme classification for uplight control. It allows no light above 90°, and in fact not one candela at 90°. Full cutoff distribution requires a flat lens.

  2. Cutoff

    3. A luminaire light distribution where the candela per 1000 lamp lumens does not exceed 25 (2.5 percent) at an angle of 90°, and 100 (10 percent) at a vertical angle of 80°.

    Typically, the difference with Full Cutoff will be the presence of a “non-flat” lens. Sagged glass means a good chance that the luminaire is not Full Cutoff, but it possibly is Cutoff.

  3. Semi Cutoff

    4. A luminaire light distribution where the candela per 1000 lamp lumens does not numerically exceed 50 (five percent) at an angle of 90 degrees, and 200 (20 percent) at a vertical angle of 80 degrees.

  4. Non Cutoff

    5. A luminaire light distribution where there is no candela limitation in the zone above maximum candela. Unrestricted distribution of light at any angle.

Dark Sky

The dark sky movement is a campaign to reduce light pollution. Its aim is to reclaim the night sky so people can see the stars, to reduce the effects of unnatural lighting on the environment, and to cut down on energy usage. Its main activity is to encourage the use of cutoff and full cutoff lights that cast little or no upward light, and to encourage communities to adopt lighting regulations.

The movement started with astronomers who were alarmed that nocturnal glow from urban areas was blotting out the sight of stars. Later, it has spread with groups like the
International Dark-Sky Association.

At Schréder we are very much aware of the light pollution issue and the need to reduce uplight. We strive to offer our customers as many cutoff and full cutoff luminaires as possible in our product range, and we take it into account in all our product development projects.

  • Cutoff Schréder luminaires include (depending on the distribution) Hestia, Alura, Francesca, Nemo luminaire, Kali, Hestia Extreme (sag lens), and Onyx.
  • Full Cutoff Schréder luminaires include Hestia Extreme (flat lens), Neos range, the Focal and the Corus.