Is the Samsung LH351 dedomable?

Lick · 2019-12-09T11:31:00.000Z

I've seen djozz take the phosphor off one on YT and everyone else is slicing them, are these impossible to dedome or are they difficult to get clean like Nichia ones? If I did slice them would a partial dedome look ugly on the beam? I'm used to taking it off, my nichia was hot dedomed, ... Poorly

Is the silicone really stuck to the phosphor?

djozz · 2019-12-09T13:15:35.000Z

I tried hot dedoming and it did not work one time. Perhaps, like Nichia’s, the phosfor is a silicone mix so there is no splittable boundary between silicone and phosfor.

But given that when sliced to right on top of the phosfor I get 800 Kelvin CCT drop, the effect is pretty close to a full dedome like the old Cree’s.

Hoop · 2019-12-09T12:12:07.000Z

Is slicing not preferable?

Lick · 2019-12-09T19:20:00.000Z

II would prefer to dedome just because I'm used to it. Would it matter if I just did a partial slicing then? I'm a bit worried about messing it up. Is the UV part the same as if I bought a UV? If so I have nothing to lose!

BurningPlayd0h · 2019-12-09T20:40:52.000Z

Slicing it is super easy and let’s you fine tune how much throwier and warmer you want them to go.

I cut mind to about down about half-way of what you safely can and like the results. They get rosier with slicing too.

Scallywag · 2019-12-09T21:46:10.000Z

Lick:

II would prefer to dedome just because I’m used to it. Would it matter if I just did a partial slicing then? I’m a bit worried about messing it up. Is the UV part the same as if I bought a UV? If so I have nothing to lose!

I believe that’s another Royal Blue LED underneath the phosphor.

moderator007 · 2019-12-10T01:48:53.000Z

I have accidental done a too much heat dedome before but the phosfor came off with the dome.
Slicing the LH351D is my preferred led of choice.
My favorite slice for tint is the 3500k UPP6 from Digikey. I ordered a few more just a few days ago. The sliced 4000k turns out pretty nice too.
Slicing makes a nicer beam in my opinion. You get a tighter better tint hotspot that doesn’t look like a TIR optic. The hotspot fades outward from the main cornea, no defined circle like with the dome on.

Wildcat · 2019-12-10T02:19:16.000Z

Hot dedome works fine.

Lick · 2019-12-10T03:04:18.000Z

To prevent too much heat, what temp should it be? I'd love to justify a laser/UV heat thermometer, they are only $8 on Ali. I'll try slicing too, I want a bootleg Rosy nichia since I don't have one anymore :(

Good to know that it's not impossible, I haven't heard anyone say it was possible and everyone was slicing theirs

djozz · 2019-12-10T07:10:25.000Z

Wildcat:

Hot dedome works fine.

No it does not. Not the common way how I (we) dedomed Cree leds in the past. It may work fine under a defined set of circumstances unknown to me (please explain, maybe with a video? ), but without further information it does not “work fine”.

Lick · 2019-12-10T13:34:52.000Z

I ruined it trying to dedome it. Is this light dangerous, in terms of uv? I have attached pics of it and beam shots, it's very ugly and 2 toned now. There is a pic with a rock and uv light versus mine as well not sure how to check how UV is is. I need a sharper razor. The pictures are in backwards order, the first is the UV lit light. Am I the first to dedome a warm light and get a cool white light?

IMG-20191210-060506 hosted at ImgBB — ImgBB

IMG-20191210-060454 hosted at ImgBB — ImgBB

IMG-20191210-060132 hosted at ImgBB — ImgBB

IMG-20191210-060114 hosted at ImgBB — ImgBB

IMG-20191210-060020 hosted at ImgBB — ImgBB

https://ibb.co/tCLF2Bx

Left LH351D 3000k badly sliced

Center LH351D 3000k

Right 219B 5700K sliced

IMG-20191210-063519 hosted at ImgBB — ImgBB

IMG-20191210-063449 hosted at ImgBB — ImgBB

https://ibb.co/ThsxskR

https://ibb.co/gJNd4R7
https://ibb.co/pQvp41K

Does it look pinkish in these shots? It kinda looks pinkish on wood but blue on walls, I think there's 3 tones on it

Ending: I made it uniform. But it's ugly. Looks like I have a very cool white emitter.

https://ibb.co/J5ZFwnX

CRI is gone. Maybe I haven't used a cool white in a while but I'm trying to decide if I like it or not. It looks so weird, I don't think I like it but I can't stop looking or trying it out. If I continue cutting it, will it turn into a UV light? Any way to remove the last of the phosphor or whatever is left?

djozz · 2019-12-10T13:47:00.000Z

The blue light is 450nm, not UV. A bit harsh on the eyes but nowhere as dangerous as UV (400nm and lower).

Lick · 2019-12-10T13:59:27.000Z

Thanks so much! Is there anything you can suggest to do with this ruined LED? Can I make it "more UV" or lower it but cutting it, or is this as low as the UV goes?

Jerommel · 2019-12-10T14:31:10.000Z

There’s simply a 450nm blue LED underneath the yellow stuff (the phosphor).
Only thing you can do is clean it up and use it as a 450nm blue LED.

Lick · 2019-12-10T14:38:29.000Z

Oh no so its useless. Thanks for letting me know!

story · 2021-10-19T01:12:54.000Z

Jerommel:

There’s simply a 450nm blue LED underneath the yellow stuff (the phosphor).
Only thing you can do is clean it up and use it as a 450nm blue LED.

Hey, so I got a Wurkkos WK30 with LH351D, red led, UV, 3 in 1.
I was going to find a blue filter to cover the LH351D. I already have the Convoy S2+ but I rather have a 3 in 1.

Seemingly, I should just remove the dome.