Getting To Know Light

Every so often, we need to go back to the basics. New lighting technology has the potential to simplify our lives, but trying to actually understand it can get complicated. Check out these helpful graphics from Bulbrite’s Lightopedia to learn how to use measurements like CRI, lumen, and Kelvin temperature to find the perfect lights for your home or building…

Watt the Heck is a Lumen?

Contrary to popular belief, watts DON’T measure the brightness of a light bulb. They measure how much energy that light bulb consumes. CFLs and LEDs consume much less energy (watts) than older filament lamps, so they’ll produce more light for every watt they consume.

If you’re still in the incandescent mindset, check out this handy conversion chart showing how many lumens each incandescent light produces:

Image via

Rendering the Color Rendering Index

If you poke around on our website, you might find that we use the term CRI (color rendering index) a bunch, describing light quality. CRI is measured on a scale from 1 to 100, and the lower the number, the more distorted the color will look under the light source. Generally a good CRI is 85+. Simple, right? Check out these illustrations:

Poor CRI via
Good CRI via

Taking the Color Temperature

First rule here: color temperature doesn’t refer to the light’s heat, but rather how warm or cool the source appears, measured in degrees Kelvin. The higher the Kelvin temperature, the cooler the light source and vice versa. Still confused? Check out this table:

Image via

Incandescent lights range from 2,700K to 3,500K while CFLs and LEDs are available across the spectrum. For more information, check out this infographic on choosing a light source.

Annie Josey

Annie was the E-Commerce Marketing Specialist at Pegasus Lighting from June 2012 to October 2013. She has a background in English literature, and loves using language to help illuminate the world. So covering lighting news and tips naturally fit her interests. In her personal time she enjoys painting, biking, and reading.