What is Cutoff Fixture

Horace He

Last Updated: August 7, 2023

What is Cutoff Fixture

A cutoff fixture is a lighting fixture that is specifically designed to minimize light pollution, glare, and light trespass with a specific light distribution pattern. A cutoff fixture directs part or all of its light downward, with less or no light emitted upwards. This design helps to reduce skyglow and light pollution by preventing light from escaping above the horizontal plane. The fixture achieves this by shielding the light source and ensuring that all emitted light is directed towards the intended area.

Full cutoff fixtures have a recessed light source and are designed to minimize glare and light trespass. By directing the light downward and preventing it from spreading horizontally, these fixtures help to reduce the negative impacts of lighting, such as visual discomfort and disturbance to wildlife. They are recognized for their superior lighting performance and are recommended for addressing light pollution and trespass.

Semicutoff fixtures, which are often used for residential purposes, emit a significant amount of light upwards, contributing to light pollution and glare. These fixtures have a bucket-shaped plastic lens and bulb that hang below the metal portion of the fixture. They are known for putting up to 35% of their light into the sky, which can be wasteful and contribute to adverse effects on the environment and human health.