LH351D slicing measurements : output, tint, tint shift, beam profile, intensity.

Very useful info!! Thanks so much for compiling all the data for us! Seems like shaving reduces output the same as using minus green filter and achieves the same lowering of DUV. Only difference I guess is shaving results in a more uniform beam and improves throw.

I have a sliced 2700k in a Tool AA. After slicing the emitter, I gained some strange artifacts in the hotspot, but after some sanding they disappeared. I’m not sure if this was because I didn’t do a great job on the initial slice, or because this light has a smooth reflector. I have another sliced Sammy in an OP reflector and it looked great without any sanding.

Yeah basically.

I don’t have this flashlight but I think I’ve heard the reflector has some issues like this with some LEDs.

I sliced a dogfart and I like it.

5000k LH351D, the good bin. I used a spacer(3 layers of thin card) to get an even cut. Had to cut from two sides to get even. Installed in a C8 with a blf a6 driver and an OP reflector.

Now one of my favourite lights. Decent throw intensity, usable spill. Even beam with no artefacts. Definitely warmer than 5kk. Seems great CRI I assume the slice doesn’t reduce CRI.

A great allrounder outdoor light.

Any chance you’ll be testing a 3500K variant? Curious about that CCTs tint shift vs current… I prefer the behavior of the 5000/5700K as Duv doesn’t change much with current. 4000k is almost perpendicular to BBL. I’m guessing 3500 is similar, but there’s only one way to know.

Thanks again. This is awesome and priceless data.

Yes, I’m going to order some stuff on digikey and I will take some 3500K.

Anything else I should order at the same time ?

Edit : Contactcr tested 3500K , it has the same behaviour as 4000K with current.

I’d be interest in how the SST20 4000k and 2700k behave in this regard as well. Also, you won’t be getting any from digikey, but I used to shave 219Bs back in the day b/c I found them too cool. They really warmed up a lot and got very peachy/rosy warm. Very beautiful but they just didn’t make enough light.

Even CW emitters like SST20/40 and XHP 50.2 would be useful data points, but mostly biased towards throw and maybe angular tint shift.

Oh and thanks for the link to contactr’s tests!

So I already tried to slice a SST-20 2700K and a XHP50.2 cool white from a Thrunite (unknow CCT)

For the SST-20 the duv barely changed, like –0.0003~–0.0005, CCT dropped ~90K, as I am most interested in tint, I didn’t deem this worthy of more testing.

For the XHP50.2 I only measured the bare LED quickly, original :

0° CCT = 8061K (Duv –0.0065)

25° CCT = 7191K (Duv –0.0031)

45° CCT = 5690K (Duv 0.0076)

60° CCT = 4802K (Duv 0.0199)

75° CCT = 4713K (Duv 0.0208)

What an absolute nightmare of an emitter :confounded:

sliced :

0° CCT = 5227K (Duv 0.0084)

25° CCT = 5101K (Duv 0.0100)

45° CCT = 4964K (Duv 0.0123)

60° CCT = 4791K (Duv 0.0152)

75° CCT = 4531K (Duv 0.0203)

Less tint shift! but the whole thing got greener. ‘throws into the trash’

I have some 219C 5000K 9050 that I could try to slice.

Good work and many numbers. But one simple question - Does this means its time to teardown my SP36 5000K and try to slice to about 1mm?
If I am reading numbers correct, I will get warmer CCT (good), even more throw (good), and a little bit lower duv (good)?

All good except some output losses (–15~–17%).

But the SP36 is not easy to open I read, the driver is glued (needed to be removed to access the MCPCB), I remember seeing somebody soldering solid wires on the driver to pull on it.

Output losses probably will be compensated by slightly better throw?
My SP36 driver is already glue free and flashed with latest Anduril. Will remove reflector and MCPCB if needed.

Yes, 170% intensity, 130% throw distance (square root of 1.7) with the optic used in the test.

I noticed less angular tint shift in my sst20 when sliced. Not too much but noticeable. It lives inside my converted fw1a with a convoy s21a reflector.

Just sliced all 4 leds on my sp36 5000k and results are good - all 4 leds working :slight_smile: This was my first slicing expierience.
CCT is closer to my sst-20 4000k and lh351d 4000k now.

That’s great.

Yes it basically makes a nicer 4000K

here is a video I posted on the mod thread, tint ramping light with sliced 5000K and 2700K next to SST20 2700K and LH351D 4000K (bigger optic so more throwy despite the domed LED)

So when finalising my order I noticed they say that you have to pay taxes and custom clearances stuff upon delivery, no way I do that, custom fees are super high in my country, I though digikey was like Mouser or Arrow, that is they declare VAT and there is nothing more to pay (I’m fine with VAT but not bullshit fees).

Anyway so no 3500K, I could get some from Convoy though, they have U6 bin.

Added 3500K, contactcr was so kind as to send me some, they are from Digikey I believe (?), I tested 2 and the other one was duv 0.0002 above.

Color rendering :

This looks great. I definitely am going to try some of these. Thanks freeman and contactr!

I didn't visit here much for a couple years and am now wading through lots of old threads to catch up. This is fantastic work and data! Thank you so much for taking the time to do this and share it with us.