What is colour binning and SDMC?

Color tolerance: It is a concept closely related to color temperature. This concept was originally proposed by Kodak in the industry, the British is Standard Deviation of Color Matching, referred to as SDCM. It is the difference between the computer calculated value and the standard value of the target light source. That is to say, the color tolerance has a specific reference to the target light source.

The photochromic equipment analyzes the color temperature range of the measured light source, and then determines the standard spectral color temperature value. When the color temperature is the same, it determines the value of its color coordinate xy and the difference between it and the standard light source. The larger the color tolerance, the greater the color difference. The unit of this color tolerance is SDCM,. Chromatic tolerance determines the difference in the light color of a batch of lamps. A color tolerance range is usually shown on the graph as an ellipse rather than a circle. General professional equipment has integrating spheres to measure specific data, and some LED packaging factories and lighting factories have related professional equipment.

We have our own test machine in sales center and factory,each sample and the first piece of production (including COB LED STRIP,NEON FLEX,SMD LED STRIP AND RGB LED STRIP)will be tested, and mass production will only be made after passing the test.We also encapsulate the lamp beads ourselves, which can be well controlled the bin of LED strip light.

Due to the variable nature of the colour produced by white light LEDs, a convenient metric for expressing the extent of the colour difference within a batch of LEDs is the number of SDCM (MacAdam) ellipses steps that the LEDs fall into. If the LEDs all fall within 1 SDCM (or a “1-step MacAdam ellipse”), most people would fail to see any difference in colour. If the colour variation is such that the variation in chromaticity extends to a zone that is twice as big (2 SDCM or a 2-step MacAdam ellipse), you will start to see some colour difference. A 2-step MacAdam ellipse is better than a 3-step zone, and so on.

However, there are many factors that affect the color tolerance, such as the reasons for the LED chip, the reason for the ratio of phosphor powder, the reason for the change of the driving current, and the structure of the lamp will also affect the color temperature. The reason for the decrease in brightness and the accelerated aging of the light source, the color temperature drift of the LED will also occur during the lighting process, so some lamps now consider the color temperature and measure the color temperature in the lighting state in real time. Color tolerance standards include North American standards, IEC standards, European standards and so on. Our general requirement for LED color tolerance is 5SDCM. Within this range, our eyes basically distinguish chromatic aberration.