# Unboxing a $500 LED... Wow.



## martinaee (Nov 5, 2017)

This guy on my feed showed off this insane LED and components in a video on YT today. Not exactly a self-contained flashlight package, but still cool (or very hot):



Also, here is the LED's company page with all the specs:

https://store.yujiintl.com/collecti...cri-high-power-cob-led-5600k-bc270h-unit-1pcs

I would love something like this for studio lighting like he mentions. And apparently very accurate color rendering on both the warm and neutral(ish) versions. 18-24k lumens depending on the color version of the emitter.


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## FRITZHID (Nov 5, 2017)

lol, i JUST posted a thread in the spotlight pages about this one. Shocking seeing that heatsink! almost looks like it should fit in a "photon canon"!  
i can't wait to see one in person!


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## martinaee (Nov 5, 2017)

FRITZHID said:


> lol, i JUST posted a thread in the spotlight pages about this one. Shocking seeing that heatsink! almost looks like it should fit in a "photon canon"!
> i can't wait to see one in person!



"LEDs don't get that hot." ---> Me before I knew anything about LEDs lol. 

To be fair though this is basically the Death Star of LEDs in 2017.

I really really want to see this put into a "flashlight package" that is at least somewhat usable in outdoor environments without being too susceptible to water/dirt and the elements. LED lighting is and is going to continue to become crazy for things like movie sets though. While 500 watts is a lot it's still a heck of a lot less than the power required to get basically any hid/filament bulb to that brightness (that I'm aware of). I read that low pressure sodium street lights are pretty efficient, but surely have no where even close to the color rendering of something like this even if they are putting out more lumens per watt.

Now we need to get this thing matched with a gigantic parabolic reflector and we'll be able to light up Pluto.


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## Scott_T (Nov 5, 2017)

very cool. seems like that noisy fan would be a detriment for studio lighting though. water cooling might be more ideal?


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## FRITZHID (Nov 5, 2017)

Scott_T said:


> very cool. seems like that noisy fan would be a detriment for studio lighting though. water cooling might be more ideal?


Was my exact thinking! Add lenses, uber high CRI throw light.


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## martinaee (Nov 5, 2017)

Yeah, some of the PC mod guys who specialize in case water cooling would be able to put together some amazing lights with these that could sustain full output and be really quiet if not close to silent. That would be great for things like movie sets.


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## ven (Nov 6, 2017)

Damn thats special Now for a quad............:naughty:


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## Capolini (Nov 6, 2017)

Maybe I will get my First Headlamp and use this for the LED to Illuminate the[ENTIRE] trail!


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## PolarLi (Nov 6, 2017)

martinaee said:


> While 500 watts is a lot it's still a heck of a lot less than the power required to get basically any hid/filament bulb to that brightness (that I'm aware of). I read that low pressure sodium street lights are pretty efficient, but surely have no where even close to the color rendering of something like this even if they are putting out more lumens per watt.
> 
> Now we need to get this thing matched with a gigantic parabolic reflector and we'll be able to light up Pluto.



This LED only put out 24,000 lumen, giving it 48 lm/W. The LED has a diameter of 19 mm.
I have a couple of mercury lamps that beat this.
A 400W Philips MSR SA lamp that puts out 30,000 lumen, so that is 75 lm/W. The arc gap/light area is 3 mm. 
And I have a 850W Ushio Emarc that puts out 70,000 lumen, that is 82 lm/W. The arc gap is only 3.5 mm.


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## iamlucky13 (Nov 6, 2017)

Scott_T said:


> very cool. seems like that noisy fan would be a detriment for studio lighting though. water cooling might be more ideal?



The same youtuber has both a smaller directly fan-cooled version, and a liquid+fan cooled version using the 100W Yuji. It's hardly a wimp itself, at 6800 lumens, and uses cheap and quiet computer cooling fans.
https://www.youtube.com/watch?v=L3LWXznJx_0

That's about the same output as the 500W halogen lights that some folks use for video lighting.

The 10W version shouldn't need a fan at all if mounted on a smallish heat sink (about the same size as those used on household LED bulbs).


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## KITROBASKIN (Nov 6, 2017)

Way to go Yuji!

Thanks to martinaee for bringing this to CPF.

What great color rendition.


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## martinaee (Nov 6, 2017)

PolarLi said:


> This LED only put out 24,000 lumen, giving it 48 lm/W. The LED has a diameter of 19 mm.
> I have a couple of mercury lamps that beat this.
> A 400W Philips MSR SA lamp that puts out 30,000 lumen, so that is 75 lm/W. The arc gap/light area is 3 mm.
> And I have a 850W Ushio Emarc that puts out 70,000 lumen, that is 82 lm/W. The arc gap is only 3.5 mm.



Output wise, sure, a lot of discharge or filament bulbs beat LEDs like this though. The color accuracy is really impressive to me though for what it is.

I'm not a huge user of high output bulbs, but honestly they terrify me. I've handled 300-400 watt bulbs before and they are DANGEROUS to me lol unless you have appropriate housings and ways to handle them. They get HOTTTT!!! At least with a cooling setup like this most of that heat will be dissipated or spread out into a large radiator. And I've seen studios in the past use HID bulbs that literally can give you serious sunburns/skinburns just by using them too long. NOPE! Though to be fair I haven't read too much about UV danger potentials from any high output LEDs. I'll have to look into that more.


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## PolarLi (Nov 7, 2017)

martinaee said:


> Output wise, sure, a lot of discharge or filament bulbs beat LEDs like this though. The color accuracy is really impressive to me though for what it is.
> 
> I'm not a huge user of high output bulbs, but honestly they terrify me. I've handled 300-400 watt bulbs before and they are DANGEROUS to me lol unless you have appropriate housings and ways to handle them. They get HOTTTT!!! At least with a cooling setup like this most of that heat will be dissipated or spread out into a large radiator. And I've seen studios in the past use HID bulbs that literally can give you serious sunburns/skinburns just by using them too long. NOPE! Though to be fair I haven't read too much about UV danger potentials from any high output LEDs. I'll have to look into that more.



If you need high CRI, there is certainly HID's for that too. Mercury lamps with 95 CRI and Xenon from 98-99. But yeah, there are definitely some downsides to HID. In a commersial application, life is the major one. But the handling aspect isn't much of an issue with mercury lamps, as they are non-pressurised cold. They can explode hot though, so you do need a proper housing. UV and heat out the front, can certainly be a problem, but again, it's mostly an issue in a professional setting where you run the light the whole day.


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## martinaee (Nov 8, 2017)

PolarLi said:


> If you need high CRI, there is certainly HID's for that too. Mercury lamps with 95 CRI and Xenon from 98-99. But yeah, there are definitely some downsides to HID. In a commersial application, life is the major one. But the handling aspect isn't much of an issue with mercury lamps, as they are non-pressurised cold. They can explode hot though, so you do need a proper housing. UV and heat out the front, can certainly be a problem, but again, it's mostly an issue in a professional setting where you run the light the whole day.



Yeah, I saw them used in a commercial studio shoot once and some people came back with literal bad "sunburns." Kind of terrifying. Do LEDs avoid that danger or can some of these ultra high output emitters do that too?


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## HarryN (Nov 16, 2017)

martinaee said:


> Yeah, I saw them used in a commercial studio shoot once and some people came back with literal bad "sunburns." Kind of terrifying. Do LEDs avoid that danger or can some of these ultra high output emitters do that too?



Usually sun burns are caused by wavelengths shorter than 450nm - closer to 400 range. HID lamps used in studios definitely emit well into this region.

The majority of "white" LEDs are made from blue / 450 - 460nm LEDs and then some of the light is phos converted to longer wavelengths. The downside of using 460nm as the starting point is that this becomes the absolute limit of how "blue" a photo can be, so some companies use LEDs slightly more into the UV range to create that really deep blue needed in studio work. Soraa was one of the first LED companies to pull this off commercially (not the first to build them, just early in commercialization).

If you look at the data sheet, there are some clues:
- AlN substrate - usually that is only done if you want LEDs that operate slightly into the UV range
- Spectral output curves - especially the 3200K version - there is some emission down below 430nm - might even be 405 - 410nm range.

This is an indicator that the LED is throwing some UV - probably not as much as a studio lamp.

As a practical matter, if your friends got a sun burn from a movie lamp, it is possible that the photographer did not have the UV protection shield in place and that is really not a good thing.


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## The_Driver (Mar 21, 2018)

PolarLi said:


> This LED only put out 24,000 lumen, giving it 48 lm/W. The LED has a diameter of 19 mm.
> I have a couple of mercury lamps that beat this.
> A 400W Philips MSR SA lamp that puts out 30,000 lumen, so that is 75 lm/W. The arc gap/light area is 3 mm.
> And I have a 850W Ushio Emarc that puts out 70,000 lumen, that is 82 lm/W. The arc gap is only 3.5 mm.



The arc of those lamps is 3D though. The surface area can't really be calculated from just the gap. It will even differ between the different bulb types. The arc of the Ushio Emarc is probaly smaller than the Philips MSR SA lamps arc, even if it's a little bit longer.

For example a 3mm long ellipsoid with a center diameter of 2mm has a surface area of 16.9mm^2. 

The Philips MSR SA lamp with 30,000lm has a CRI of 75. This substantially increases efficiency and makes it unusable for uses where the light quality is important. 

The Yuji LED doesn't have a uniformely lit up surface. The surface of the individual dies is a bit smaller than a 19mm circle because of the gaps between them. Still, it's rather inefficent though. A Xenon short-arc bulb is not much less efficient and has compareable light quality.


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## Genzod (May 1, 2018)

Driver--Your mail box is full.


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## lumen aeternum (Jun 6, 2018)

So what does it take to turn one of these COBs -- even the smaller 50 or 100 watt versions -- into a working light?
I see they sell also something with a high CRI as a pre-made standard light bulb.


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## iamlucky13 (Jun 14, 2018)

lumen aeternum said:


> So what does it take to turn one of these COBs -- even the smaller 50 or 100 watt versions -- into a working light?
> I see they sell also something with a high CRI as a pre-made standard light bulb.



You need a driver that supports the correct voltage and current, and obviously batteries that give the driver what it needs to function. I posted a DIY Perks video above of a light he built and then swapped the Yuji 100W into.

Here's the older video he did of building the light in the first place with a generic LED in it:
https://www.youtube.com/watch?v=c--5c3Egv4E&t=819s

I've go an order of Yuji's 10W COB I've been sitting on because I lost access when I changed jobs to the tools I was going to use to build a custom heat sink / optics holder for it. They're "only" rated for a little under 1000 lumens, but they can be driven by a Luxdrive Buckpuck, Flexblock, or Boostpuck driver with some common battery setups. Buckpuck should run it reasonably well with an 18V tool battery. If I remember the minimum voltage specs right, Flexblock and Boostpuck can run it with 2 x 18650. They also seem to pair well with Carclo 30mm TIR optics.

Eventually I'll have some spares to resell. I just need to get in gear and do my planned projects. Mine are the warm version (3200K).


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## id30209 (Jun 14, 2018)

iamlucky13 said:


> You need a driver that supports the correct voltage and current, and obviously batteries that give the driver what it needs to function. I posted a DIY Perks video above of a light he built and then swapped the Yuji 100W into.
> 
> Here's the older video he did of building the light in the first place with a generic LED in it:
> https://www.youtube.com/watch?v=c--5c3Egv4E&t=819s
> ...



Regarding driver, smaller BC160H (100W) can be driven by DIWdiver driver (35V max, 25A max adjustable).


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## lumen aeternum (Jun 15, 2018)

Actually I was thinking in terms of an AC operated light for household lighting. Are the black boxes used to power LED lamps generic?


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