Traditional based lighting, such as metal halide technology, provides light output generally in a spherical pattern in all directions.  The traditional lighting can provide a glowing “orb” appearance that is not too harsh on the eyes and provides light in all directions. 
Over the last few years, light emitting diode (LED) based lighting has become more ubiquitous for providing light in large factories.  There are many advantages to using LED based lighting, such as improved efficiency, reliability, and the like.  The LED lights, however, are point source lights and may emit light in a more focused direction.  In addition, the LED lights may have a different appearance.  For example, the LED lights may have a brighter light output than the traditional lighting that may be harsher on the eyes and appear more pixelated than the traditional lights. 
In certain applications, the LED based lighting may not provide enough up light for large factories.  The result may be a “cave effect” in the factory where an upper portion of the factory may appear dark.  The LEDs also may not provide enough light to light cat walks and other areas that are located above the lighting.