When using LED’s it is important to understand three concepts？
2) Light appearance
3) Color rendering
First, we have to let go of the misconception that wattage equals brightness. While for incandescent bulbs wattage and brightness had a direct correlation, this is not true for LED products and since LED’s consume much less power (Watts), it’s impossible to compare brightness of an incandescent and an LED bulb based on wattage.
So the only factor to pay attention to when looking for brightness of an LED light is Lumens. Lumen is the unit of measure for brightness and tells us how much light a particular lighting product emits.
The color appearance or correlated color temperature (CCT) of light is measured in kelvin (K). When we want to know if a lighting fixture or bulb creates a warmer or crisper, cooler light we need to look for the kelvin number. The lower the number, the warmer the light will be and the higher the number the more cool and blue the light will appear. A typical incandescent bulb has a color temperature between 2700K and 3000K. The sun at noon on a clear day produces a light of approximately 5500K.
Light sources differ in their ability to display the colors of objects “correctly”. And by correctly we mean compared to a natural light source like the sun or an incandescent bulb.
The color rendering is expressed as the Color Rendering Index or short CRI. The scale goes from 0 to 100. A 2700K spot light has a CRI of 80.
A value of above 80 is with current LED technology considered a good CRI and will be sufficient for most applications. However, for some areas, better color rendering of 90 or above can be desirable.