someone had to do it: dedomed Nichia219highCRI :-D

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UliBär
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Ok, you all decided to ignore my post, but nonetheless my reception of the colors isn’t that wrong – at least my colleagues back me for that. So i suspect you all to simply ignore the facts! :þ

Wink

Aloha, Uli

18sixfifty
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the one thing I have noticed in de-doming XM-L2’s is that it doesn’t matter which one you start with they all end up the same exact tint when de-domed as long as you don’t destroy the phosphor layer or whatever that’s called. So isn’t it basically the dome itself that is giving the tint and CRI or am I missing something?

I’m a junky, I mod lights so I can sell lights so I can buy more light to mod so I can sell lights to buy more lights to mod.

lightme
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UliBär wrote:
Ok, you all decided to ignore my post, but nonetheless my reception of the colors isn’t that wrong – at least my colleagues back me for that. So i suspect you all to simply ignore the facts! :þ

I think the 5B1 shows a bigger difference between tints in the reds and blues. Even the yellows look close with the Nichia but it does have them beat with greens and tans. I think it’s just a little too warm. That 3C ain’t too shabby either. Both also have better greyscales indicating a more neutral white.
lightme
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18sixfifty wrote:
the one thing I have noticed in de-doming XM-L2’s is that it doesn’t matter which one you start with they all end up the same exact tint when de-domed as long as you don’t destroy the phosphor layer or whatever that’s called. So isn’t it basically the dome itself that is giving the tint and CRI or am I missing something?

http://hyperphysics.phy-astr.gsu.edu/hbase/geoopt/aber2.html

If you look at the light emitted from the edge of a domed mule, you’d see that it’s yellow and with a reflector, it forms the yellow corona around the hotspot. I don’t dedome but I suspect it gets rid of that aberration and more yellow hits the reflector’s sweet spot.

UliBär
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lightme wrote:
UliBär wrote:
Ok, you all decided to ignore my post, but nonetheless my reception of the colors isn’t that wrong – at least my colleagues back me for that. So i suspect you all to simply ignore the facts! :þ

I think the 5B1 shows a bigger difference between tints in the reds and blues. Even the yellows look close with the Nichia but it does have them beat with greens and tans. I think it’s just a little too warm. That 3C ain’t too shabby either. Both also have better greyscales indicating a more neutral white.

The 5B1 shows a clearly better purple than the dedomed Nichia, but the blue is similarly pale/dark to the blue of the dedomed Nichia. All in all the CREE 5B1 isn’t that bad, but the untouched Nichia still rock’s da house, sorry! Wink

Aloha, Uli

lightme
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UliBär wrote:
The 5B1 shows a clearly better purple than the dedomed Nichia, but the blue is similarly pale/dark to the blue of the dedomed Nichia. All in all the CREE 5B1 isn’t that bad, but the untouched Nichia still rock’s da house, sorry! Wink

So you don’t deny that the tints for certain colors on the Nichia are closer to each other? And the other two are also more neutral? If it wasn’t so warm, it’d be perfect but it’s changing the true colors. Overall, the 5B1 chart look darker so I’m guessing that raising the XML’s voltage a bit will brighten things up.
UliBär
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lightme wrote:
So you don’t deny that the tints for certain colors on the Nichia are closer to each other? And the other two are also more neutral? If it wasn’t so warm, it’d be perfect but it’s changing the true colors. Overall, the 5B1 chart look darker so I’m guessing that raising the XML’s voltage a bit will brighten things up.

I would rate the LEDs in following order:

1 ) Nichia 219A 4300K 92CRI
2 ) XM-L2 5B1 80CRI
3 ) XM-L2 6A1 80CRI
4 ) Nichia 219A 4300K 92CRI dedomed
5 ) XP-G2 mystery LED
6 ) XP-G “high CRI
7 ) XP-G2 3C
8 ) XM-L2 0D

But this is only my personal perception. YMMV.

I own a Balder BD-1 modded from the original XP-G R5 1C to 4500K Nichia 219A B10. This light is so dam’n good in color reproduction, i even use it in macro photography to brighten up dark flowers and other objects in front of the lens.

Aloha, Uli

lightme
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If I had to make a list, I’d ignore how vibrant the colors appear and look for the chart that shows the most distinctly different colors. The dedomed Nichia would be dead last. The medium light grey is nearly the same as the light skin and yellow-green looks like yellow. Many of those colors are supposed to represent what we see in nature so (to me) having colors match defeats the purpose of high CRI especially outdoors. Honestly, I’d love to have both to compare before I jump to conclusions.

JungleCoffee
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djozz wrote:

There is absolutely no point dedoming this wonderful led with the best CRI around and beautiful neutral tint, causing the tint to go warm and the output to go down, other than: I was curious about it Smile

 ...

No point, unless someone is looking for the benefit of a dedomed LED + the highest CRI.

 

If I am looking to throw as far as possible some green light, I will choose that :

 

More seriously. We are living in a society obsessed with gaining quantity, always more quantity, quite often unnecessary.

It is easier to score higher lumens using some ugly dedomed emitters (some Korean's bird shit signature)

than appreciating nuances and details...

 

 

...

 I personally discovered the 219B dedomed properties by accident (I scratched the dome when hot during manipulation) By curiosity, I fixed back the reflector and was positively surprised by this "specific warm light"

 

The 219b dedomed definitely keep a high CRI, also add-on a nice & comfortable tint* - some kind of soft amber (with an orange dominant) and a hint of pink.

Any wood surface, skin or warm objects look like hot-braise illuminated (incandescent). 

 

For a true neutral white with High CRI the latest 219B-v1 (with dome) do a perfect job. Really neutral.

 

For comparison:

219C 5k, 219B-50 V1, 219BT 45 dedomed

 (wall color, off-white with a tiny hint of green, ... It proves that the 219C reacts more on greens...)

 

About the 219C sample, I had to de-saturate the "green coloration" rendered (increased) by the camera sensor (S5 WB set on daylight)

 

here is what the camera reproduced:

219C 5000K flood

Both 219b (with or without dome), reproduce colors quite well and do not disturb the camera sensor with "extra greenish"...

High CRI is not based (exclusively) on the temperature K, even though warmer LED tend to cover a wider spectrum.

 

 

*Comfortable tint:

For more than 100,000 years, human eyes have been genetically optimized to work with orange/red source of illumination during night time. Fire-torch light.

 

More lumens are always welcome, but they should come along with high CRI. The 219c will be interesting with a 90+ CRI rating.

 

 

 

 

 

Suum cuique

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Haha. Yes, I did the same thing with my first Nichia C from RMM not long ago — I just touched the dome accidentally with my clamp right after soldering the wires to the board and zip, dome gone (luckily leaving a fragment right over the connecting wires). Mentioned it in RMM’s thread and he said that kind of accident is how he learned about dedoming too. Soooooo easy to do.

Lovely result, too.

Is there some kind of sealant that can be painted on to protect the phosphor from volatiles? I recall reading that the phosphor will absorb anything that outgasses and change color over time.

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That kind of neutral coating should be available...

Some led even have a thermochromic coating (cheap alternative to nanophosphors) 

 

 

By the way, did phosphors have been damaged on your 219C? By checking some other posts, dedoming the C seems quite difficult.


...Or is it the method?..



Also, the new manufacturing process for the C series seems not to include an extra 1st (protecting/or filtering?) coating like the B. Could you confirm?

About the C tint, do you have some images sample of your dedomed 219C - outdoor pics?

Suum cuique

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I hope its not against the rules to bump such an old thread, but I did want to thank diozz for this thread. I used the hot dedome method, and some of the phosphor came off my 219b but it still works wonderfully.

 

I had two hot dedomes, one was from a fresh emitter swap, and the other was induced after I tried how a 5700K 219B would look. It looked absolutely awful. 

 

The first one did not have any phosphors come off, and has a very warm color. The 2nd lost some of it and has a very clean neutral color. I got these LEDs with the intention to dedome them. I used a cheap razor blade as well.

 

For anyone trying to dedome them, I have had success so far, and its not that bad, but its still a rather intense process.  heres some of the phosphor that came off.

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This is indeed a rather long time ago, it isa 219A and I can see now that the it has a different way the phosfor layer is applied than the 219B and 219C (those have a low rim around the phosfor, this 219A led does not have that).

Lick
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Is there danger of degradation on the LED? One dedomed with 2700k ish and this one was 4500k ish.

djozz
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Lick wrote:

Is there danger of degradation on the LED? One dedomed with 2700k ish and this one was 4500k ish.


I have not had anything happened to my dedomed leds yet (my flashlight do not get much runtime at all and certainly not on highest setting), but some have reported dedomed leds failing early.
Lick
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Anything I can do to maybe prevent that? I hope it doesn't happen but maybe it was a heat problem of theirs too when soldering.

djozz
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Lick wrote:

Anything I can do to maybe prevent that? I hope it doesn’t happen but maybe it was a heat problem of theirs too when soldering.


Yes, with the limited number of reports (I do not think I can find back who suffered from it) the failing of dedomed leds is IMO a bit anecdotical, it is possible that the failing is caused by something different like a bad reflow or leaving dirt on the dedomed surface.

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