Reference LED (Bin Standard)
LED Samples to Test
Results Per LED Sample
| Label | CIE x | CIE y | u’ | v’ | Delta u’v’ | MacAdam Steps | Status |
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LEDs of the same type are not all identical, and manufacturers sort them into bins by color and brightness. If LEDs from different bins are used together, such as in a long strip or an array of downlights, the color differences can be visible. This calculator checks how closely the colors match using the MacAdam ellipse.
A MacAdam ellipse is a region on the color chart in which people cannot see a difference in color. A one step ellipse is barely noticeable, and larger steps are more obvious. A three step tolerance is considered premium and is used in high quality lighting, four steps is standard, and five or six steps is typical for lower cost products where the color shift is more noticeable.
To keep the color uniform, buy all the LEDs for a project from the same batch and ask the supplier for the bin code. Order a little extra at the start, because a later order may be from a different bin. Compare the color of fixtures side by side before installing them, and use tighter tolerances where lights are seen next to each other.