Tagged with 'Tunable white'

Human Centric Lighting, a return to daylight basics

Human Centric Lighting

For most of history, humans lived, worked and slept under the governance of natural light. The flickering light of candles was a poor substitute and did little to change the rhythm of life for all but the wealthy few.

Life went on under a dynamic light ,with changing tone and brightness, as a day went by and seasons changed. Then, one day, electric light was invented and everything changed. From that point forward a "golden hour" or "afternoon" could be at any time of day, on any point on the planet or beyond, outside or inside, from our living room to a windowless office or deep underground.

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Nichia LEDs Light Color guide

White light has different shades  and while there is no general consensus, warm white light for LEDs has a value of 2500K-4000K on the color temperature scale, pure white 4000K-5000K and cold white 5000K-10.000K.

Warm white LEDs, as with all manufactured products, have material and process variations that yield products with corresponding variation in the shade of white light emitted.  For example Nichia warm white LEDs just out of the production line can have a color temperature between 2580K and 4260K.  If they would be directly integrated into strips or luminaries they will yield color inconsistent products that are generally unusable. 

 To overcome this problem, LEDs must be color sorted by the manufacturer with additional further sorting down the supply chain, if necessary. 

Color sorted LEDs are grouped in batches known as "Chromaticity Bins". Nichia, as a LED manufacturer, groups white LEDs in many Bins, thus allowing very good control of the white light color of your project.

The Nichia Bins for new generation LEDs start with the letters "sm" follower by a series of numbers, where the frist two describe the color temperature (65 as in 6500K) while the last two narrow down the selection interval.

Nichia also offers color sorting in 3step, 5step and 7step MacAdam ellipses. While a detailed explanation of LED color sorting can be found here, we recommend that you choose the color sorting based on your project:

  • General Lighting: 3step
  • Ambient Lighting: 3step or 5step, where 5step could be more affordable
  • Street and Christmas lighting: 7step
  • Flashlights:  5step or 7step

Chromaticity Diagram of Nichia LEDs for

General Lighting - MacAdam

whiteWHITE
  sm653 sm655 sm657 sm573 sm575 sm577 sm503 sm505 sm507
x 0.3123 0.3123 0.3123 0.3287 0.3287 0.3287 0.3447 0.3447 0.3447
y 0.3282 0.3282 0.3282 0.3417 0.3417 0.3417 0.3553 0.3553 0.3553
a 0.002709 0.004515 0.006321 0.003087 0.005145 0.007203 0.003555 0.005925 0.008295
b 0.006561 0.010935 0.015309 0.007809 0.013015 0.018221 0.008418 0.014030 0.019642
Ø -32.35 -32.35 -32.35 -31.56 -31.56 -31.56 -31.78 -31.78 -31.78
warm whiteWARM WHITE
  sm453 sm455 sm457 sm403 sm405 sm407 sm353 sm355 sm357
x 0.3611 0.3611 0.3611 0.3818 0.3818 0.3818 0.4073 0.4073 0.4073
y 0.3658 0.3658 0.3658 0.3797 0.3797 0.3797 0.3917 0.3917 0.3917
a 0.003852 0.006420 0.008988 0.004071 0.006785 0.009499 0.004098 0.006830 0.009562
b 0.009009 0.015015 0.021021 0.009282 0.015470 0.021658 0.008796 0.014660 0.020524
Ø -34.33 -34.33 -34.33 -35.95 -35.95 -35.95 -35.47 -35.47 -35.47
  sm303 sm305 sm307 sm273 sm275 sm277
x 0.4338 0.4338 0.4338 0.4578 0.4578 0.4578
y 0.4030 0.4030 0.4030 0.4101 0.4101 0.4101
a 0.004107 0.006845 0.009583 0.004056 0.006760 0.009464
b 0.008391 0.013985 0.019579 0.007872 0.013120 0.018368
Ø -36.05 -36.05 -36.05 -36.05 -36.05 -36.05

Older generation Nichia LEDs use a different sorting method. Here MacAdam is not possible and color sorting is not as good. Example: 5mm and 3mm Nichia LEDs.

General Lighting - ANSI Bin

whiteWHITE
  Rank sw65
x 0.3070 0.3040 0.3207 0.3221
y 0.3113 0.3300 0.3462 0.3261
  Rank sw57
x 0.3221 0.3207 0.3376 0.3366
y 0.3261 0.3462 0.3616 0.3369
  Rank sw50
x 0.3366 0.3376 0.3548 0.3515
y 0.3369 0.3616 0.3736 0.3487
warm whiteWARM WHITE
  Rank sw45
x 0.3515 0.3548 0.3736 0.3670
y 0.3487 0.3736 0.3874 0.3578
  Rank sw40
x 0.3670 0.3736 0.3996 0.3898
y 0.3578 0.3874 0.4015 0.3716
  Rank sw35
x 0.3898 0.3996 0.4299 0.4147
y 0.3716 0.4015 0.4165 0.3814
  Rank sw30
x 0.4147 0.4299 0.4562 0.4373
y 0.3814 0.4165 0.4260 0.3893
  Rank sw27
x 0.4373 0.4562 0.4813 0.4593
y 0.3893 0.4260 0.4319 0.3944

General Lighting - Nichia Color LED sorting

blueBLUE
  Rank W (464~475nm)
x 0.137 0.124 0.110 0.132 0.142 0.151
y 0.037 0.058 0.087 0.112 0.081 0.058
bluish greenBLUISH GREEN
  Rank C (495~500nm)
x 0.04 0.04 0.12 0.12
y 0.39 0.49 0.49 0.39
  Rank D (500~505nm)
x 0.05 0.05 0.13 0.13
y 0.48 0.58 0.58 0.48
  Rank E (505~510nm)
x 0.06 0.06 0.14 0.14
y 0.55 0.65 0.65 0.55
  Rank F (510~520nm)
x 0.09 0.09 0.17 0.17
y 0.60 0.70 0.70 0.60
greenGREEN
  Rank G (520-535m)
x 0.183 0.131 0.163 0.206 0.237 0.207
y 0.625 0.725 0.740 0.740 0.640 0.635
YELLOW
  Rank K2 (577~583nm)
x 0.484 0.492 0.532 0.522
y 0.498 0.507 0.467 0.460
RED
  Rank Rmp1 (618~628nm)
x 0.6874 0.6705 0.6873 0.7049
y 0.2966 0.3135 0.3126 0.2948

Specialty Lighting - Nichia white or color LED sorting

whiteWHITE
  Rank a0
x 0.280 0.264 0.283 0.296
y 0.248 0.267 0.305 0.276
  Rank b1
x 0.287 0.283 0.330 0.330
y 0.295 0.305 0.360 0.339
  Rank b2
x 0.296 0.287 0.330 0.330
y 0.276 0.295 0.339 0.318
  Rank c0
x 0.330 0.330 0.361 0.356
y 0.318 0.360 0.385 0.351
blueBLUE
  Rank W (464-475nm)
x 0.11 0.11 0.15 0.15
y 0.04 0.10 0.10 0.04
bluish greenBLUISH GREEN
  Rank C (495-500nm)
x 0.04 0.04 0.12 0.12
y 0.39 0.49 0.49 0.39
  Rank D (500-505nm)
x 0.05 0.05 0.13 0.13
y 0.48 0.58 0.58 0.48
  Rank E (505-510nm)
x 0.06 0.06 0.14 0.14
y 0.55 0.65 0.65 0.55
greenGREEN
  Rank G (520-535m)
x 0.14 0.14 0.22 0.22
y 0.64 0.74 0.74 0.64
  Rank H (535-545m)
x 0.21 0.21 0.28 0.28
y 0.65 0.73 0.73 0.65
AMBER
  Rank L (583-595nm)
x 0.603 0.532 0.522 0.589
y 0.397 0.467 0.460 0.393
RED
  Rank R (615-635nm)
x 0.67 0.67 0.73 0.73
y 0.27 0.33 0.33 0.27