Wattage isn't the only feature to look for when buying light bulbs - understanding lighting terminology can help you choose the right bulbs for every room in your house.
Watts measure the amount of energy needed to power the bulb.
A lumen measures how much light a bulb produces. A 100-watt bulbs usually produces about 1750 lumens.
The efficacy, or energy efficiency, of a light bulb is measured by lumens per watt. Divide the lumens produced by the number of watts used; the higher the total, the more energy-efficient the bulb.
Each type of bulb has a color temperature based on its "coolness" (red, yellow, orange) or "warmness" (blue or green). Cool light produces higher contrasts, so it's good for specific tasks like reading or studying. Warm light is better for general lighting and taking photographs because it flatters skin tones and clothes.
Bulbs are also measured by their color rendering index, or how true colors appear compared to bright sunlight. Incandescent bulbs are closes to natural sunlight. High-pressure sodium bulbs, used in many commercial fixtures, render colors poorly - which is why it's sometimes difficult to distinguish between similar colors in stores. |
