Hid Colour Temps

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fluke
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Hid Colour Temps

Can anyone explain how HID 4300K has highest lumen output, yet 6500K LED is highest lumen output,

Firelight2
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Here’s my guess:

White LEDs are composed of blue LEDs with a layer of yellow phosphor on top. When the LED is turned on, some of the blue light passes through into the output. Another portion of the blue light is absorbed by the phosphor. The phosphor molecules go to an excited state. Those molecules then shed energy to revert back to their original state and while doing so they emit red light, green light, and heat.

This phosphor excitation process isn’t 100% efficient. Some of the blue light that hits the phosphor is absorbed as heat. A 2-stage process like this is always less efficient than a 1-stage process with no phosphor.

To get warmer color temperatures from a white LED, a thicker layer of phosphor is needed so that the overall output contains more red and green and less blue. More phosphor means more light is absorbed and produces heat rather than light so efficiency goes down. The result is warmer color temperature white LEDs should always be less efficient and produce fewer lumens than a comparable cool color temperatures of the same LED.

In contrast, HID lights work with a completely different mechanic. In an HID, an electric arc passes through gas. As it does so the gas molecules become excited and emit light. The type of light you get depends on the gas used. There is no phosphor excitation like in a white LED.