De-doming Nichia219B - anyone done it?

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Chicken Drumstick
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De-doming Nichia219B - anyone done it?

Just wondering if it’s possible/worth de-doming the 219B nichia?

Does the normal petrol/gasoline trick work with these?

And what happens to the tint?

Cereal_killer
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I tried, it didnt work for me, tried both gas and hot dedoming. Gas didnt seem to effect the dome like it does a cree dome, it didnt fall off whole like cree’s do, it crumbled (like if you only leave a cree in for an hour and then try, but I left it set for 24 hours before tapping it and it still just crumbled and didnt come off clean) and there was to much damage. With the hot dedome method the phosphor layer pulled off…

Good luck, if you find a suitable method I’d be interested to hear it.

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pilotdog68
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I haven’t tried it simply because I figured it would become too warm for my taste.

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tryps
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How good is your German? Big Smile

Link to TLF

Just use google-translate, short story: keeps pretty nice coulor and dome does not go off completly. Slicing it off with a razorblade seems to work fine.

sma
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The difficult thing with TLF is that pictures which are attached (that is, not hosted externally) are only shown after login.

But a few words help enough: There seem to be several silicone variants to be involved, and some don't go off easily. But this doesn't matter, as enough silicone goes off.  Luminance increases about almost 80% (in contrast to 95% with Cree LEDs). I don't think the slightly smaller increase is due to some silicone remaining but due to the characeristics of the LED die and/or phosphor. An MT-G2 with some silicone remaining after slicing off the dome showed the usual Cree-like increase for me. It's no problem for luminance if a thin layer remains. So, like tryps mentioned, in case of emergency Smile if the remains are ever too high or rough, slicing off the dome is always an option. Let alone there are no bonding wires.

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Why would you willingly do this to an LED designed primarily for its high CRI? De-doming kind of defeats the point of it. You’ll get better throw from a XP-G2, if throw is what you want.

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ToyKeeper wrote:
Why would you willingly do this to an LED designed primarily for its high CRI? De-doming kind of defeats the point of it. You’ll get better throw from a XP-G2, if throw is what you want.

There might be some who want high CRI with their throw. Also some might wonder if the tint shift on dedoming a Nichia is less than dedoming an XPG2.

chouster
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Maybe take a look at the Luxeon Z ES, no dome, high cri.

djozz
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I dedomed a few Nichia's, 219A and 219B, I used a hot method: warm up to just under reflow temperature, slice the dome in a bit on the side close to the substrate with a scalpel and slowly lift it up. Dedoming a Nichia feels different, the Nichia silicone is very tough, and as mentioned a thin layer of silicone remains on the die afterwards. (video of dedoming a 219A here, description of dedoming a 219B here)

The tint of the Nichia 219B high CRI after dedoming is the best led tint I have ever experienced. It is in my current EDC, a small 16340 cheapie with 2900mA NANJG-driver (build thread here).

Dedoming any high CRI led (I dedomed quite a few 80CRI Cree XM-L2 leds as well) does not result in ugly tints in my experience, it makes the tint warmer but the colour reproduction qualities seem intact. Ugly tints result if you start out with certain low CRI leds.

sma
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djozz wrote:
Ugly tints result if you start out with certain low CRI leds.

 

...or more specifically, if you start with very high color temperature.

I also doubt that CRI suffers but I haven't measured it. High CRI is due to a well selected phosphor which remains unchanged.

I measured the color shift of an N219B-R85 SW45 here (LED no 7), and it shifts in the same direction like Cree LEDs (that is, same danger of greenish tint depending on original color bin) but even to a smaller amount.

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Looks like I’m going to have to try this.

For awhile I was using only dedomed emitters in my zoomies. I liked the extra throw and wider flood allowed by the dedome.

However, recently I’ve started going back to domed emitters. I was getting sick of the ugly green and yellow tints my dedomes had. With the domes on:

  • I get a lot less throw – bigger and wider die image, but much less lux.
  • Flood is maybe 10-15 degrees narrower – the LED’s lens prevents me from modding the light’s retracting the bezel to retract closer to the phosphor in flood mode. In my dedomed emitter zoomies I’ve modded them so the lens stops literally about half a mm above the phosphor. This gives a beam angle around 90 degrees … far wider than any stock zoomie other than my Coast HP1.
  • Tint is enormously improved – my latest mod is a tiny 14500 zoomies. Current emitter is an XPL 3D tint on Noctigon.
  • slightly higher lumens – Flood beam isn’t as wide, but it’s noticeably brighter.

I’d go back to dedomed emitters if I could get one with a whitish tint without the green though. I miss the laser-like throw.

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FWIW, the flood mode on a cheap UF-838 is about 90 degrees without modding it. IIRC there are a couple other extra-wide zoomies too, but I don’t remember their names.

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Just had my first attempt dedoming a Nichia 219B.

Not bad… definitely throwier with no tint shift to green like in the Cree LEDs. The tint got warmer, but if anything this just makes it look like the tint of a Nichia 219a. Still very pleasing.

Stuck it in a small zoomie with 3 amp driver and run on IMR 14500. I could definitely see this as a pocket EDC light.

Biggest downside to me is the overall low output. Standing alongside a similar sized zoomie with the same driver and a domed CREE XPL there’s no comparison. The dedomed Nichia throws slightly further, but the floodbeam on the XPL feels like its 4x as bright.

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Firelight2 wrote:
Just had my first attempt dedoming a Nichia 219B. Not bad... definitely throwier with no tint shift to green like in the Cree LEDs. The tint got warmer, but if anything this just makes it look like the tint of a Nichia 219a. Still very pleasing. Stuck it in a small zoomie with 3 amp driver and run on IMR 14500. I could definitely see this as a pocket EDC light. Biggest downside to me is the overall low output. Standing alongside a similar sized zoomie with the same driver and a domed CREE XPL there's no comparison. The dedomed Nichia throws slightly further, but the floodbeam on the XPL feels like its 4x as bright.

Comparing the output graphs of the Nichia219b and the XP-L(2A),  a cool white XP-L could well be 3 times as bright as a dedomed Nichia219b. (the voltages are roughly the same btw, so they will draw a similar current)

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I just did a Nichia 219A by accident. Had a canted optic and it sheared the dome off. The tint is now closer to 3200K instead of 4500K. Very nice golden yellow. Makes me think of evening sun. I’ll try it for a while to see what I think. The hot spot is tighter too.

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Few pictures of dedomed Nichia NVSW219BT-V1 R9050 D220 LED

bellow PD32UE with Nichia 219b (with dome)

remark: the XML-T6 has a neutral color (yes) but dirty. Circles of green, yellow…
With the 5000k Nichia 219b, it is really an homogeneous tone (absence of tone!) If you look at the beam on the A4 white paper, PD32UE modded with the 219b provide a grey nuance. 5000k from Nichia is really a very neutral white

Only when you compare it with a 6500 xml or a tube cool white, you can realize that the 219b is a “warm neutral” (the pinkish Nichia’s signature is still there, but much less than the 219a)

For information:
the domed 219b is something that can be qualified as “pure white” it looks like no coloration at all but with high CRI.

About the dedomed version, it is really special> looks like an old incandescent flow but brighter! Because of it is temperature bellow 4000k (3400 or 3500k?) it give a nice orange/amber coloration. Very pleasant to the eyes, especially on outdoor. Most interesting, the CRI remain very high. A lot of contrast with a warm tone.

(poor quality picture… smart phone things)

This picture does not give a good representation of the high contrast provided by the dedomed 219b… AUTO ISO has changed of that shot.

Some new project with dedomed 219b in thrower on the way…

Suum cuique