Trying to find a CFL (compact fluorescent light) bulb that actually mimics the soft light of an incandescent bulb? It may be an impossible task. Low-wattage CFL bulbs that are marketed to replace the commonly used 60- and 75-watt incandescent bulbs can emit light that is too bright for comfort.
The U.S. Environmental Protection Agency’s Energy Star website claims that Energy-Star-certified CFL bulbs are available in warm colors that match the yellow glow of incandescent lights. But CFL bulbs with the recommended lower (warmer) Kelvin temperature rating, in the 2700 K to 3000 K range, do not yield that soft, slightly-yellow glow of an incandescent bulb.
CFLs with ratings from 3500 K to 4100 K that the EPA recommends for kitchens and work spaces can be blinding if located directly overhead in a conventional nine-foot ceiling, and the 5000 K to 6500 K rating that the EPA recommends as good for reading would send many people scrambling for their sunglasses to dim the glare. CFLs do a good job on saving energy and providing bright light, but they do not provide the same tone of light as incandescent bulbs.
The EPA’s interactive Choose a Light Guide is useful because it gives the names for the different shapes of bulbs that are available and points out which shapes and types of bulbs are best for a particular use. Lumen output, not wattage, is supposed to be the key to comparing the brightness of a CFL bulb to that of a traditional incandescent bulb because a CFL uses much less energy to produce an equivalent amount of light. Choosing a CFL bulb in the warmest range (lowest K) available, with an 800-lumen output said to be equivalent to a 60-watt incandescent bulb and the truest color rendering index possible (CFLs only gets as close as 91 to an incandescent bulb’s 100), still won’t yield the old, friendly glow of incandescent light.
As one person complained on The Straight Dope website: 'The white CFL light is okay, I mean it performs its function perfectly well, but I want the old color back.'
A CFL is a fluorescent light source that emits intense light in a limited number of wavelengths, as do LED (light-emitting diode) bulbs, while incandescent light sources emit over a broad spectrum of wavelengths. Repositioning light fixtures or choosing shaded fixtures in areas where soft light is desired can help a little. Buying more expensive tri-phosphor CFLs may help, but as long as the energy source is a line-emitter rather than a broad-spectrum source of light, the light it casts will not be the same. For those who want to relax in the glow of a soft light, a CFL can’t hold a candle to the old-fashioned incandescent bulb.
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