The Homeowners Comprehensive Guide to Lighting

Lighting Basics

To effectively light a home enough of the right kind of light for the occupants to function within the space is required.  This can mean anything from highlighting a treasured masterpiece on a wall, enabling the pool shark to line up their shot without shadows, or creating a relaxing mood to unwind after a stressful day.

Through-out this series we will take you through the different terminology, types and functions of various lights while providing tips for you to utilize in your upcoming renovation.  Stayed tuned every Tuesday for the next article.

This weeks article will cover some terminology that will help you understand upcoming articles better.

Terminology

Lighting intensity is measured in Lumens (lum).  In the Metric System, one lumen is the amount of light energy that falls on a spherical surface of one square meter, produced by a single candle.  The American System uses Footcandles (fc), where on fc is the amount of light that falls on a square foot of spherical surface at a distance of one foot from the candle.  The relationship between lumens and footcandles is 1lum = 12.57 fc.  

Color Temperature is an index of how the light source, itself, looks to us, measured in degrees Kelvin (K).  Warm light sources have color temperatures less than 3000K.  Light sources between 3000K and 4000K are considered neutral in color.  Anything above 4000K is cool.

Color Rendition is an index of how the light makes objects appear.  How accurately a lighting source defines objects is measured by the Color Rendering Index (CRI).  The best score is 100, the CRI of sunlight.

Both Color Temperature and Color Rendition are important because sources with the same CRI can produce different moods at different color temperatures and artifical light sources vary widely in their color rendering indices.