A non-cutoff luminaire is an outdoor light fixture that does not limit light emitted above the horizontal or at high angles, so it sends light in all directions, including upward and sideways.
Older acorn, globe, wall-pack and drop-lens fixtures are common examples. In parking lots and on garage roofs, they waste energy, cause glare for drivers and pedestrians, add to skyglow, and spill light onto neighbors. The older cutoff classifications have largely been replaced by the IES BUG rating system, which rates a fixture’s backlight, uplight and glare separately.
In parking facilities
- Replacing non-cutoff fixtures with full-cutoff LED fixtures usually cuts energy, reduces glare and improves uniformity at the same time. See LED lighting.
- Many lighting ordinances now prohibit non-cutoff fixtures or set maximum uplight ratings.
- Decorative fixtures can be specified with internal shields or full-cutoff optics. See cutoff luminaires.
The Parkonomics view
Light that goes up does no work for anyone parking. Non-cutoff fixtures are an easy first target in any lighting upgrade.
Related terms: Cutoff Luminaires, Light Pollution, Glare, Light Trespass, LED Lighting