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Lighting Basics

August 15, 2013 - 5:12pm


There are many different types of artificial lights (formally called "lamps" in the lighting industry,) which have different applications and uses. Types of lighting include:

New lamp designs that use much more energy-efficient technology will start appearing in the residential market during the next few years. It is important to use the correct terminology when researching the type of lighting you want in your home or business, and when you discuss lighting with sales representatives. This website uses industry terms and, where necessary, relates those terms to terms people often use.

Lighting Comparison Chart
Lighting Type Efficacy
Color Rendition Index
Color Temperature

Linear Fluorescent Lamp (LFLs)

(Also known as "tube" or "straight tube" fluorescents.)


(For simplicity, the efficacy range excludes the losses associated with the ballast.)

7000–24,000 50–95 (fair to good) 2700–6500 (warm to cold) Indoors/outdoors
Compact Fluorescent Lamps (CFLs) 33–70; for the most common A19 replacements, 65–70 10,000 77–88 (good) 2700–6500 (warm to cold) Indoors/outdoors
Circline 40–50 12,000     Indoors
High-Intensity Discharge
Mercury Vapor 25–60 16,000–24,000 50 (poor to fair) 3,200–7,000 (warm to cold) Outdoors
Metal Halide 70–115 5,000–20,000 70 (fair) 3,700 (cold) Indoors/outdoors
High-Pressure Sodium 50–140 16,000–24,000 25 (poor) 2,100 (warm) Outdoors

Standard "A-19"

(Commonly called "light bulbs," "bulbs," or "A-19 bulbs.")

10–17 750–2,500 98–100 (excellent) 2,700–2,800 (warm) Indoors/outdoors
Energy-Saving Incandescent (or Halogen) 12–22 1,000–4,000 98–100 (excellent) 2,900–3,200 (warm to neutral) Indoors/outdoors
Reflector 12–19 2,000–3,000 98–100 (excellent) 2,800 (warm) Indoors/outdoors
Light-Emitting Diodes
Cool White LEDs 60–94 25,000–50,000 70–90 (fair to good) 5000 (cold) Indoors/
Warm White LEDs 27–88 25,000–50,000 70–92 (fair to good) 3300 (neutral) Indoors/ outdoors