Comment 5620

By Number33 (anonymous) | Posted February 23, 2007 at 17:25:33

As for the comments above on CRI, CRI only tells you how far a light deviates from the blackbody curve AT A GIVEN COLOR TEMP, it can't be used to compare lights of different color temp. So incandescent are 100 CRI by definition, but that doesn't mean their color rendering is realistic. When most people say that color from CFLs looks bad, they're genereally referring to 2700K CFL designed as an incandescent "look-alike", I agree that those generally look terrible. CFLs in the 3500-4100K range (if you can find them) have both higher CRI and a more useful color temp. It's important to note though that the higher the color temp, the brighter the light you need for it to look good.

As for the LEDs -- no way are they anywhere close to a 40W incandescent for light output. The most efficient LEDs on the market right now, Cree XR-E (5500-6500k, around 84 CRI, good lights but definitely not "warm white"), are about 100 lumens per watt when underdriven and heatsinked. Accounting for optics losses and ballast losses this light might be able to put out around 300 lumens if they're using the best LEDs on the market. (I doubt they are using LEDs this efficient anyway since they didn't explicitly state any lumen numbers)

Realistically I expect this light is probably under 200 lumens. A typical 40W bulb is about 480 lumens, and a typical 9W CFL (Available for $2.50 at Home Depot) is over 500 lumens.

While I think LEDs have great potential for replacing halogen spotlights (since LEDs can be focused efficiently) they won't be able to compete for good electronic ballasted fluorescent for area lighting. Two T8 tubes in a highly efficient reflector can put out almost 5000 lumens from the fixture from 64 watts of power, and about $35 up front. (A 65W reflector bulb puts out only around 700)

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