Overhead lighting presents the challenge of providing adequate lighting while reducing glare. In the computer era, this is especially difficult due to reflections off computer monitor screens. Lithonia introduced the RT5 volumetric lighting fixtures in 2004 as a solution to this issue.  These fixtures spread light evenly throughout a space, functioning both with surface or recessed mounting. The fixtures correct for many problems of its popular predecessor, the parabolic fixture. These problems include “cave effect,” harsh shadows, and low fixture efficiency (~65%).

Volumetric lighting is achieved by integrating lamp shielding and using Fresnel reflection to diffuse the compact brightness of the T5 lamp it uses. Luminaire efficiency should be well above 70%. Significant energy savings are achieved over T12 and T8 systems, and further enhanced if combined with dimming. Kits are available to convert existing fixtures to this distribution, and LED source fixtures are also available.