Understanding Color Rendering
The eye sees all objects in the form of reflected light. All of the colors contained in the object must also be present the beam of light to accurately reproduce the image in reflected light. The Color Rendering Index is a numerical scale from zero to one hundred used to rate the accuracy at which a light source will render colors. A value of 100 CRI indicates perfect color rendering. There is, however, another factor to consider in the color equation… the amount of light. Low light levels make an object lack color and look dull, or grayish.
Natural daylight contains all the colors in the visible
light spectrum, plus the Power, or Energy Level of the
light in each color is nearly consistent across the entire
Ceramic Technology Lamp
The latest advancements in Ceramic Technology technology
provide lamps with high color temperature
(CCT) and a variety of high CRI values available for
various applications, vastly improving visual acuity. In
addition, Ceramic Technology lamps feature long lifetimes,
similar to HPS lamps. Ceramic Technology lamps
are an excellent choice where visibility, good color
rendering and minimized maintenance are required…
in other words—virtually everywhere!
Metal Halide Lamp
A typical Metal Halide lamp does not contain all of the
colors in the light spectrum. Additionally, the color
power levels are inconsistent.
High Pressure Sodium Lamp
High Pressure Sodium (HPS) lamps are great for photopic
(ability to see in bright light) lighting conditions
and have been used primarily outdoors due to its high
efficacy (lumens per watt) and long life characteristics.
The light from sodium sources is predominantly emitted
in the longer wavelengths, between yellow and red.
HPS lamps are suitable for applications where color
rendering is not a crucial concern.
Mercury Vapor Lamp
Clear Mercury lamps produce white light with a bluishgreen
tint. While it may not be flattering to human
skin color, it is an outstanding choice for foliage and
landscape lighting applications. Mercury lamps with a
phosphor coating on the outer lamp envelope help to
somewhat correct this color rendering issue.