- Relax is 2700K color temperature which is most closely equivalent to traditional incandescent bulbs.
- Refresh is 5000K color temperature and is much bluer more equivalent to daylight sun.
- Reveal is 2850K color temperature which is in between the 2 other versions.
Why does CRI – Color Rendering Index Matter?
Why have I never heard of Color Rendering Index?
The CRI index ranges from 0 to 100. 100 is perfect on the scale. Old school incandescent bulbs were by their nature a CRI of 100 so before high-efficiency bulbs came on the market color rendering was irrelevant. Today LED bulbs are becoming the standard for lighting. They typically have a CRI of around 80 which is considered good enough and the most important metric to most people is the cost. The lowest cost bulb is the driver of the light bulb market and high CRI bulbs are typically more expensive. Thus the majority of the LED bulb market is made up of low-cost bulbs with a good enough Color Rendering Index of around 80. However, when you see the difference a high CRI bulb makes in the pleasantness of your environment you may come to see as I have that a few dollars more for a better experience is worth it.
Why are there so few high CRI bulbs on the market?
Again it comes down to cost being the most important metric for most people. CRI is very difficult to attain on incandescent replacement bulbs while maintaining energy efficiency. The CRI value is typically ignored on product packaging and few people understand CRI is a metric to consider. High CRI bulbs tend to use more energy and be more expensive. Thus the market demand for these bulbs is low. Some of the leading LED brands such as CREE used to have high CRI bulbs that have been discontinued in favor of cheaper, higher power efficient bulbs.
In 2008, the US Department of Energy created the Bright Tomorrow Lighting Prize also known as the L Prize to find an incandescent light bulb replacement with a CRI above 90 that met certain energy requirements. Philips was the winner of this competition and began selling their bulb in 2012. The bulb was a 60 Watt equivalent, used 10 watts and had a CRI of 92 but it started at a price of $50-$60 and has since been discontinued. According to Amazon, it was replaced with this bulb, but the Philips tech on the answers page says the CRI for this new bulb is only 83. It appears like CREE, Philips has also abandoned high CRI bulbs.
Which Color Temperature Bulb should I buy?
For home use and for most people the color temperature 2700K will be the most comfortable light that is most reminiscent of traditional incandescent bulbs. The 5000K temperature is also very popular and is typically called daylight. 5000K is a very blueish light that will make you feel like you stepped into a department store, and can be very jarring if you were not expecting it. 5000K bulbs are best in an industrial setting such as a laundry room or garage. For the traditional home settings of the dining room or living room, 2700K is the best color temperature.
What about Halogen Bulbs?
Halogen Bulbs like Incandescents have a CRI around 100. However, there are several trade-offs comparing against LED. First Halogen bulbs typically last around 1000 Hours. Whereas LED bulbs can last as much as 50,000 Hours. Secondly, Halogens use a lot more power than LED. For a 60W equivalent, Halogens use around 40 Watts whereas a 60W equivalent LED uses 10 or less Watts. If you want the best CRI period go for halogens but for a more balanced approach when it comes to lifespan and energy use an LED with a high Color Rendering Index is the best bet.
Other High CRI LED Bulbs On The Market
Now that Cree and Philips no longer manufacture High CRI bulbs, there are few options available. There are the above GE models, and FEIT Electric makes a 60-watt equivalent for $6.85 at the time of writing with a CRI of 93. There are a few lesser known brands such as a company called Hyperikon based in San Diego California that manufacturers a 60 watt equivalent bulbs that boasts a CRI of 90+ and is currently $9.95 for one bulb, but cheaper only $3.95/Bulb if you buy a multi-pack.