2000k flashlight

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wle
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“The CRI is determined by the light source’s spectrum. An incandescent lamp has a continuous spectrum, a fluorescent lamp has a discrete line spectrum; the incandescent lamp has the higher CRI.”

so how can any led have decent CRI?

since its ‘white light’ is basically just blue and yellow, no red and no continuous spectrum?

i;m trying to learn here, not just being difficult..

wle

SKV89
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wle wrote:
ok i still don;t get it
you can adjust to anything, apparently
i have a 3000K light [astrolux s1] and it looks too yellow to me

wle

Your eyes take at least 45 minutes to adapt. What is the color temperature of your indoor lighting? Are you looking at 3000k daytime, under 5000k ceiling lighting, or WW ceiling lighting?

wle
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warmish leds is mostly the interior lighting

though i have cooler ones in the kitchen, maybe 3500k

wle

cetary
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SKV89 wrote:

Your eyes take at least 45 minutes to adapt. What is the color temperature of your indoor lighting? Are you looking at 3000k daytime, under 5000k ceiling lighting, or WW ceiling lighting?

wle, to add onto this, are you looking at a computer/smartphone/tablet/TV without blue blocking filters as well? Do you have an LED street light or high powered security light outside any of your windows?

Also, I don’t know if you’re using fluorescent, but most household LED products are at least one nominal CCT higher then advertised. So verifying that those LEDs are 3500K and not 3800K, would be helpful but not likely possible in determining what light is actually around you. That verification can only be done with a pricey spectrometer, unfortunately.

Tally-ho
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wle wrote:
so how can any led have decent CRI?

since its ‘white light’ is basically just blue and yellow, no red and no continuous spectrum?


Nope, see here the spectral power distribution of the Nichia 219B in the FW3A (red line compared to the black line which is the reference light source), it is not just made out of blue and yellow wavelengths.

Maybe this will help you to understand a few more notions : https://www.flexfireleds.com/what-is-tm-30-15-and-cri-and-cqs

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See also this Maukka’s test here, for the Nichia Optisolis 5000K for example.
On the middle upper graph, see how the optisolis 5000K (in red) is close to the reference light’s CQS, hence its excellent CRI ratings.

cetary
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Quote:
so how can any led have decent CRI?

since its ‘white light’ is basically just blue and yellow, no red and no continuous spectrum?

There is indeed red in a high quality LED. I like this colorized spectral power graph as you can better visualize what the component parts, like the cyan, greens, reds, and so on, of nearly “ideal” white light.

The reason why florescents have such poor color rendering and color qualities is their spectral power. They have an in-ordinate amount of green light, along with allot of yellow in this case, and almost no red and cyan. Compare the spectrum of this 3000K fluorescent to the same 3000K high- CRI LED at the top to see what I mean. You see all the chunks missing?

Fluorescent does exist in 90 CRI form factors typically used in high quality indoor lighting, but even that has too little red and too much green.

Rexlion
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wle wrote:
cetary wrote:
wle wrote:
dumb question, but how could 2000K have a high CRI? wouldn;t it be too yellow, and not render blues and purples accurately?

How could 6000K have high CRI, wouldn’t that be too blue, and not render reds/oranges accurately? Chromatic adaptation is the mechanism that in the human eye that corrects for CCT/SPD differences.

Sorry if that came off as snobish.

i don’t get it
it seems it doesn;t matter either way?


The “what we see” representations are a bit off, I think. With the 3000K light the red color of the ball and other reddish things will stand out more brightly even if the eyes have had time to adjust, in my experience. But otherwise the principle holds true. Just think of any time you’ve worn sunglasses for a while, then took them off.
wle
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cetary wrote:
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so how can any led have decent CRI?

since its ‘white light’ is basically just blue and yellow, no red and no continuous spectrum?

There is indeed red in a high quality LED. I like this colorized spectral power graph as you can better visualize what the component parts, like the cyan, greens, reds, and so on, of nearly “ideal” white light.

The reason why florescents have such poor color rendering and color qualities is their spectral power. They have an in-ordinate amount of green light, along with allot of yellow in this case, and almost no red and cyan. Compare the spectrum of this 3000K fluorescent to the same 3000K high- CRI LED at the top to see what I mean. You see all the chunks missing?

—i see how led is different from fluourescent, but i am confused
are you saying there are red phosphors in LEDs?
i thought it was just blue from the led, and yellow from the phosphor..
and somehow the blue+yellow appeared white due to some eye trick

wle

Fluorescent does exist in 90 CRI form factors typically used in high quality indoor lighting, but even that has too little red and too much green.

wle
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cetary wrote:
SKV89 wrote:

Your eyes take at least 45 minutes to adapt. What is the color temperature of your indoor lighting? Are you looking at 3000k daytime, under 5000k ceiling lighting, or WW ceiling lighting?

wle, to add onto this, are you looking at a computer/smartphone/tablet/TV without blue blocking filters as well? Do you have an LED street light or high powered security light outside any of your windows?

Also, I don’t know if you’re using fluorescent, but most household LED products are at least one nominal CCT higher then advertised. So verifying that those LEDs are 3500K and not 3800K, would be helpful but not likely possible in determining what light is actually around you. That verification can only be done with a pricey spectrometer, unfortunately.

i don’t know really

i don;t really expect colors to look right at night anyway, so if it is a little off, i don;t get alarmed at it

also around the house, there are many light sources
warm leds
daylight leds
some cfl
led tv
phone
computer screen
phone

so asking what light source i use in addition to the flashlight, and then requiring 45 minutes to get used to each one, or is there a streetlight out the window, or is the moon full, doesn;t really make sense

wle

cetary
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The YAG phosphors do indeed push red and deep red to. That’s where their efficiency drops off. The low color rendering LEDs have little red light, but are a bit more efficient. The high color accuracy lights, preferred around these parts, push more red/cyan.

The reason I asked about the phones, smart devices, TVs, and such is that their LED back panels are typically color calibrated for daytime use, and have color temperatures routinely near 6000K. Running F.Lux, or some other blue reducing software, removes the blue and shifts the screen to a warmer color. Looking at a bright 6000K LED screen can skew your adaptation to very blue light sources and make lights like 3000K appear more yellow then what they really are. The “daylight” LED with its 5000K color temperature, as well, will skew things if used allot at night like on a table lamp nearby for reading.

Quote:
i don;t really expect colors to look right at night anyway, so if it is a little off, i don;t get alarmed at it

Sounds like you need some high CRI lighting, minimum 90 CRI preferably 95 CRI. Your state does not, unfortunately, have the same Title 24 law the California does that mandates a minimum of 90 CRI for all LED replacement lamps. This law was put in place because of how poorly 80 CRI CFLs did. They distorted colors and gained a bad reputation. Title 24 was put in place to make peoples’ experiences with LED more positive by pushing industry towards high quality light.

SKV89
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Has anyone took any measurements of the Luminus Cube. They sound very interesting.

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SKV89 wrote:
Has anyone took any measurements of the Luminus Cube. They sound very interesting.

https://download.luminus.com/datasheets/Luminus_MP1616_1103_Datasheet.pdf

has a 1.6 × 1.6mm footprint, see page 10

they do sound interesting. been reading everything i can get to figure out how to get one to work.

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DBSAR wrote:
I have modded a lantern with 2000K LEDs, its basically a “Kerosene lamp yellow flame on low” tint. A very, very warm yellowish glow, but i like it for night lights & moon light modes. I bought a lot of 2000K flame-yellow cheap LEDs from Ebay for that purpose, (the 1W Luxeon bead-type LEDs.

which lantern did you end up modding? that sounds quite interesting!

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SKV89 wrote:
Has anyone took any measurements of the Luminus Cube. They sound very interesting.

I would like to but they are only from sellers that ask high shipping costs to the EU. I wait until I have a nice list with other leds too before I order them.
SKV89
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djozz wrote:
SKV89 wrote:
Has anyone took any measurements of the Luminus Cube. They sound very interesting.
I would like to but they are only from sellers that ask high shipping costs to the EU. I wait until I have a nice list with other leds too before I order them.

Looking forward to your test! Big Smile

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SKV89 wrote:
djozz wrote:
SKV89 wrote:
Has anyone took any measurements of the Luminus Cube. They sound very interesting.
I would like to but they are only from sellers that ask high shipping costs to the EU. I wait until I have a nice list with other leds too before I order them.

Looking forward to your test! Big Smile

haha i didn’t understand your question.. obviously not physical measurements

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SKV89
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Thanks for posting that. Disappointed that R9 is not 90+ like the E21A 2000k. Wonder what the DUV and Rg is.

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SKV89 wrote:
Thanks for posting that. Disappointed that R9 is not 90+ like the E21A 2000k. Wonder what the DUV and Rg is.

I’m pretty sure the E21A at 2000K R9 is at around 50. the variant that Virence sells is 9050. most of the other E21a he sells is 9080 except the 2000K and 2200K

http://www.nichia.co.jp/specification/products/led_spec/NVSLE21AT-E(3825J)R70%20R8000%20R9050%20R9080.pdf

SKV89
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I measured the E21A 2000k 9050 in Tiara Pro:
CCT: 2016K
DUV: -0.0003
R9: 89.2
Rg: 101
Rf: 94

Maukka’s measurements were very similar

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SKV89 wrote:
I measured the E21A 2000k 9050 in Tiara Pro:
CCT: 2016K
DUV: -0.0003
R9: 89.2
Rg: 101
Rf: 94

Maukka’s measurements were very similar

wow, that’s pretty awesome. good to know! i think i want more e21a in 2000K now Smile

SKV89
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Maukka got R9 of 89 at 1000ma but got R9 of 98 at 100ma. So at lower output, R9 is higher. I haven’t tested the low output because too lazy to close the shades to test but I’m sure it will be the same. I love this emitter for late night use especially because how little blue wavelength it emits.
https://imgur.com/a/xP55G

staticx57
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SKV89 wrote:
Thanks for posting that. Disappointed that R9 is not 90+ like the E21A 2000k. Wonder what the DUV and Rg is.

Thus far I have been too cheap to purchase CT&A. I can take a DUV with another program. By the way the test is at 350mA across 12 emitters. These Xnova cubes are not high power LEDs. They spec even less than the optisolis for drive current. Far from E21A output.

staticx57
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The 1800k Xnova is also unique as it will make the 2000k E21A look white. 1800k starts to cross into lighting that looks yellow.
1800k xnova on the left and E21A on the right

Black Flat Yellow not white flat amber


black flat yellow

xnova

flame

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SKV89 wrote:
Maukka got R9 of 89 at 1000ma but got R9 of 98 at 100ma. So at lower output, R9 is higher. I haven’t tested the low output because too lazy to close the shades to test but I’m sure it will be the same. I love this emitter for late night use especially because how little blue wavelength it emits. https://imgur.com/a/xP55G

yes to low blue wavelength at night! Are there any other good options for mcpcb that can run the e21a other than the Virence mcpcb?

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staticx57 wrote:
flame !{width:50%}https://i.imgur.com/SkNvdTW.jpg!

the flame looks so good. time to replace all my LEDs with flame

SKV89
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Keep in mind positive duv emitters when placed next to negative duv emitters of the same color temperature will make the negative duv emitters look white. My HI CRI LED strip with very negative DUV looks like NW when placed next to my 60 CRI very positive DUV led strip. Both measured 3000k but the very negative duv led strip looks 1000k cooler.

SKV89
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xenotar80 wrote:
SKV89 wrote:
Maukka got R9 of 89 at 1000ma but got R9 of 98 at 100ma. So at lower output, R9 is higher. I haven’t tested the low output because too lazy to close the shades to test but I’m sure it will be the same. I love this emitter for late night use especially because how little blue wavelength it emits. https://imgur.com/a/xP55G

yes to low blue wavelength at night! Are there any other good options for mcpcb that can run the e21a other than the Virence mcpcb?

I don’t think so. I buy all my E21A presoldered onto Virence boards. I’ve been modding a bunch of AAA lights with E21A and Optisolis using his 10mm boards. Personally I like the E21A much better than Optisolis.

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xenotar80 wrote:
staticx57 wrote:
flame !{width:50%}https://i.imgur.com/SkNvdTW.jpg!

the flame looks so good. time to replace all my LEDs with flame

Yes, the flame’s output is so natural looking. Unfortunately it’s not as easy to EDC a flamin’ torch (I mean, that long piece of wood sticking out of the pocket might be misinterpreted). Silly Um, how much runtime can one get on a Zippo?

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