Sdcm lighting

1. What is Sdcm in lighting?
2. How is Sdcm calculated?
3. Why is Sdcm important?
4. What is 3 step MacAdam ellipse?

What is Sdcm in lighting?

Standard Deviation Colour Matching (SDCM) is a statistical technique used to define how closely (or not) two colours match each other. If two colours are within 1 standard deviation of each other they will appear to most people to be the same.

How is Sdcm calculated?

In short: You need to compare your u'v' data with the nominal u'v'_nom data of different nominal CCTs (based on IEC 60881). With the euclidean distance in u'v' colour space between u'v' and u'v'_nom, you can determine the SDCM.

Why is Sdcm important?

SDCM has the same meaning as a “MacAdam ellipse”. it determines the light color of LED lights in similar color temperature. Why SDCM is important for LED lighting? Most LEDs are binned at the 4-7 step level, in other words you certainly can see colour differences in LEDs that are ostensibly the same colour.

What is 3 step MacAdam ellipse?

For a “3-step” ellipse, the boundary represents 3 standard deviations from the target, and so on. ANSI recommends that lamp manufacturers stay within a “4-step” ellipse. This means that, given a certain target point on the CIE diagram, lamp manufacturers are given a fairly wide range of perceptible differences.