Good question!
First, a little about me: I’m not a lighting engineer, but I’ve tested and reviewed light bulbs for CNET for over five years now. That includes hundreds of hours in our homemade lighting lab — a climate-controlled room equipped with a spectrometer and an integrating sphere that lets us run the most scientific and accurate light bulb tests we can possibly run. I’ve also visited and written features about major North American lighting manufacturers such as Cree and GE to get a better understanding of their methods and standards. This is one of numerous LED buying guides and roundups that I try to update as often as possible.
A peek inside our integrating sphere.
We load each bulb we test into the center of our integrating sphere — a big, hollow ball with special, reflective paint coating the inside. Our spectrometer peeks in through a tiny hole in the side of the sphere, with a “baffle” that blocks it from looking directly at the light bulb. Instead, the bulb’s light bounces around inside, which lets our spectrometer take reliable, calibrated measurements for things like brightness and color temperature.
We log those brightness measurements every 10 minutes for 90 minutes, then take a final reading at the end. At that point, I plug the sphere’s power cord into a variety of dimmer switches, then measure for the average maximum and minimum settings across all of them while also keeping a close lookout for flicker or buzz.
Once a bulb we’re testing is done in the lab, we take a close look at things like light spread, tone and color quality. Our photo and video team (Tyler Lizenby, Chris Monroe and Vanessa Salas here in Louisville) are a huge help at this point, with standardized photography that lets us take a really close look at those metrics. They’re also just really damned good at taking pictures of light bulbs.
All of that said, the most important thing isn’t what I think when I’m taking readings in our lighting lab — it’s what you and your family think after screwing the bulbs in and turning them on in your living room or other area. Like I said, LEDs like these are designed to be durable and waterproof and last years, so it’s well worth buying ones that you’ll actually like living with. You’ve got a lot of good options these days, so there’s really no need to compromise. I’m just here to help you find those “just right” bulbs a bit faster — or more efficiently, you might say.
This new floodlight LED from Sylvania isn’t available outside of California yet, but it’s efficient, putting out 93.7 lumens per watt. It’ll be one of the next bulbs I review.
