What is the foot-candle rating? Why is it usually more important than a fixture’s lumen output?
Foot-candles are a measure of how much light is projected on a given surface area from a certain distance. Because LED light is directional, foot-candles can tell you how much light there will be in the location you want it to be.
Suppose you’re looking at an incandescent fixture with a very high lumen output, which is the total amount of light emitted. Its lumen output may be higher than an LED fixture to which you’re comparing it, but because LED light is directional, the LED fixture may project more light where you actually need it. This is what foot-candle measurements will tell you.
We are presently testing all of our LED lighting to get accurate illuminance data and will be constantly updating this information on our website as this information is gathered.
How important is CRI?
Many of our customers ask us about the CRI of our LED lighting because they want to make sure they faithfully represent the colors of the objects they are illuminating. However, the CRI was introduced at a time when a second generation of fluorescent lamps were being brought onto the market and is not as applicable to newer light sources.
The National Institute for Standards and Technology has criticized CRI for not correlating well in practice with color rendering quality, with respect to LED lighting. Numerous other sources have stated that CRI is not a good indicator for use in visual assessment, especially for sources with a CCT below 5000 Kelvin.2
While we list the CRI rating for many of our products, it is important to note the variability and unpredictability with this standard with respect to LED lighting.