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?
“Chromatic adaptation is the human visual system’s ability to adjust to changes in illumination in order to preserve the appearance of object colors. It is responsible for the stable appearance of object colors despite the wide variation of light which might be reflected from an object and observed by our eyes…An object may be viewed under various conditions. For example, it may be illuminated by sunlight, the light of a fire, or a harsh electric light. In all of these situations, human vision perceives that the object has the same color: an apple always appears red, whether viewed at night or during the day (unless it is green). On the other hand, a camera with no adjustment for light may register the apple as having varying color. This feature of the visual system is called chromatic adaptation, or color constancy; when the correction occurs in a camera it is referred to as white balance.”
So the human vision equivalent of white balance is known as Color Constancy. I learned something new! Not the best source, but it’ll get the job done in this case.
Most typical households use 2700K light bulbs. Incadescent light bulbs from yesteryears are 2400K and 100CRI. Candle flame is 1800k and 100 CRI. If you use an E21A 2000K 9080 in the day time, it will look too yellow and not like it like my own experience when I first received my Tiara Pro 2000k from Virence.com. A few months later, I used it at night when my eyes are adapted to the darkness and warmth, and the color rendering is amazing. It didn’t look overly yellow at all and good thing is it doesn’t wake up sleeping family members like my other flashlights do on low output because it contains almost no blue wavelength.
Also if you test a 4000k light at night when your eyes are adapted to 2700k or 3000k ceiling fixtures, it actually looks slightly bluish. It’s all about your eyes adjusting to the color temperature.
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
Yeah the wizard pro mcpcb is 16mm. I’ll have to wait til Virence gets it back in stock as it seems like the best option for that particular light. I was chatting with him and another 16mm board is ready to be sent off for production but he has some large projects currently is very busy at the moment. But I think I’ll still want to play with the luminus cube 1800K in a different host.
“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
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?
warmish leds is mostly the interior lighting
though i have cooler ones in the kitchen, maybe 3500k
wle
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.
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 : What's the difference between CRI, CQS, & IES TM-30 and why is it important?
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.
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.
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.
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
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.
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.
Has anyone took any measurements of the Luminus Cube. They sound very interesting.
has a 1.6 x 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.
which lantern did you end up modding? that sounds quite interesting!