Short & Simple Definitions to help you decipher light bulb labels and choose what works best for you, without all the technical-babble. (Only includes common household and biohacker lighting terms)
Incandescent
The old standard light bulb that is slowly disappearing from store shelves. These were great back then, but compared to modern LED light bulbs, they use a lot of power and cost up to 10 times more to use.
Halogen
Basically incandescent lights with a little halogen gas inside. This gives the light a whiter look and extends the life of the light bulb. They still use a lot of power, though slightly less than an incandescent bulb.
CFL (Compact Fluorescent Lamp)
Fluorescent lights use less power than incandescent and halogen light bulbs. These mini fluorescent lights often have a lower CRi score (See CRI) around 80, so they aren’t the best for mimicking daylight. The term ‘integrated’ just means it’s ready to use out of the box.
LED
The new low power, long life lights. They come as bulbs, light strips, built-in fixtures, and more. RGB versions can change color, Others come in warm or bright white varieties. Some are dimmable (The dimmable ones often look different than most LED lights) They usually cost more, but they last so long that it’s much cheaper to buy LED lights in the long run and the yearly power costs are significantly lower. You will have saved money using an LED light usually within the first 3-4 months, even with the higher purchase price.
W (Watt)
A measurement of how much power is used per hour. It’s also commonly used as a brightness comparison, e.g. the brightness of a 100 Watt incandescent light bulb. (even though it’s not a measure of brightness)
Lumens
Measures how bright a light is. Most of us compare the brightness of a light to its equivalent in incandescent light bulb Watts. A 100 Watt incandescent bulb is 1600 lumens (14W LED), whereas a 40 Watt incandescent bulb is 450 lumens (6W LED).
E26/E27
The standard light bulb screw size. (E26-USA/E27-UK) They are both practically the same size, so similar in fact that they are interchangeable.
Color Temperature (Kelvin)
The color temperature of a light shows how much blue it has. Blue fire is hotter than orange fire. The same idea applies here. Daylight lights have a much higher temperature, (measured in degrees Kelvin, a common scale used in research.) whereas warm lights have a lower temperature.
CRI, CRi (Color Rendering Index)
A measurement of how accurate colors show under the light on a scale of 0-100. The colors one can see are altered by a light source. Lights with a score above 85 more closely mimic daylight and let you see colors more accurately. Halogen bulbs are typically very high, often around 100, whereas the best LED light bulbs are typically around 90-95. This means you can still get the benefits of daylight inside without the high power costs of halogen bulbs.
Diffuser
A cover over a light that spreads the light around so it doesn’t glare in one direction. Think of white paper in front of a light, it spreads the light around.
IP (Ingress Protection) – For Outdoor and Bathroom Lights
Basically dustproof and waterproof ratings for light bulbs. The higher the number the stronger the protection. Look for ratings of IP44 and IP65 for outdoor and bathroom use.
Ambient Temperature – For Outdoor Lights
Most lights are used indoors where extreme temperatures don’t really happen, but for outdoor lights, this matters. Many lights can’t handle extreme temperatures, so if you need a light where this is a problem, look for lights that have a high ambient temperature rating.
For More extensive details on light bulb labels that may apply to your house see the chart below.
