good question!
First, a little about me: I’m not a lighting engineer, but I have been testing and reviewing light bulbs for CNET for more than five years. This includes hundreds of hours spent in our home-made lighting laboratory—a climate-controlled room equipped with a spectrometer and integrating sphere that allows us to conduct the most scientific and accurate light bulb testing possible. I also visited and wrote feature articles about major North American lighting manufacturers such as Cree and GE to better understand their methods and standards. This is one of many LED buying guides and reviews that I update as often as possible.
A look inside the integrating sphere.
Each light bulb we tested fit into the center of an integrating sphere—a large, hollow ball with a special reflective paint coating on the inside. Our spectrometer peeks through a small hole in the side of the sphere, and has a “baffle” that prevents it from looking directly at the bulb. Instead, the bulb’s light is reflected internally, which allows our spectrometers to make reliable, calibrated measurements of things like brightness and color temperature.
We recorded brightness measurements every 10 minutes for 90 minutes and then took a final reading at the end. At this point, I plugged the sphere’s power cord into various dimmer switches and measured the average maximum and minimum settings across all dimmer switches while paying close attention to flickering or buzzing.
Once the bulbs we test are finished in the lab, we carefully examine factors like light diffusion, hue, and color quality. Our photo and film team (Tyler Lizenby, Chris Monroe and Vanessa Salas in Louisville) was a huge help with this, and standardized photography allowed us to really take a closer look at these metrics. They are also very good at taking photos of light bulbs.
All that said, the most important thing is not what I think when I take the readings in the lighting lab, but what you and your family think after you screw in the bulbs and turn them on in your living room or other area. As I said, these types of LED lights are durable, waterproof, and built to last, so it’s well worth purchasing an LED light that you’ll actually enjoy using. You have 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 faster, or you might say, more efficient.
Sylvania’s new floodlight LED isn’t available outside of California yet, but it’s very efficient, putting out 93.7 lumens per watt. This will be one of the next bulbs I review.
