The higher the LED light efficiency, the lower the color rendering index?

The higher the LED light efficiency, the lower the color rendering index? This is obviously not true. First of all, the causal relationship of this logic is a bit counter-intuitive, not because the light effect is low, but it is high, but to improve the index and sacrifice some light effects. And many people still have some misunderstandings about the light effect:

Light efficiency = luminous efficacy

Light effect

The luminous flux (lm) emitted by the LED source divided by the power consumed by the source (W) is called the LED efficacy in lm/W. The illuminating effect refers to the visual effect.

For this question from netizens, FAE Wu Xiaotong from Langmingnas gave a more detailed answer:

Factors affecting the color rendering index

Most of the commercial LEDs are now coated with a blue phosphor chip (YAG) yellow phosphor on the blue LED chip . We usually call it yellow powder. The blue light emitted by the chip complements the yellow light emitted by the phosphor to form white light.

If you want to improve the color rendering of LEDs, you need to calculate the color rendering index. In general, the color rendering index is calculated as R1-R8, and the chromatogram is relatively narrow.

But this will also lack a very important spectrum, which is the special index R9, red R9 (saturated red;) is an indicator to evaluate the quality of red reproduction. For their application, studios, studios, etc. need to reproduce the skin color, and the color reproduction of raw fruits and vegetables is irreplaceable.

▲R9 is also an important indicator to measure the color rendering of LEDs.

▲The light color of fruits and vegetables under different R9, the bigger the R9, the better the performance of red.