I get lots of questions from my interior design clients about LED lighting after they have been looking at fixtures and lamps for their homes. I thought that many other people are also confused and curious about what LED lighting is and why they may want to choose it. So here is a primer that will make you think like a pro next time you are shopping at the lighting store or on-line.
The Color Rendering Index (CRI) is a measure of light source's ability to reproduce color compared to natural light. Incandescent bulbs score high, with a CRI rating of 100. Mass-market LED bulbs often fall around 80 CRI. More energy-efficient compact fluorescents are also around 80 CRI, but one reason they stalled at 25 percent market share is that people don't like the twisted look of the bulb or the lighting quality.
Brightness or Light Output
This number, which refers to the amount of light produced, is measured in lumens. It's not the same as watts, which is the amount of power needed to light a bulb, but many consumers seek comparison. A 60-watt incandescent bulb produces about 840 lumens, while a 100-watt produces 1600 lumens.
This is the degree of warmness or coolness of a light source measured in kelvins. Warm light is found in the lower temperature range and is similar to the yellow glow of an incandescent bulb. It's preferred for living spaces because it casts a better light on skin tones. Cool light at higher temperatures provide higher contrasts for people performing visual tasks. It is often found in offices and can appear bluish.