Does anyone have an experience with buying from Beijing Yuji's High CRI led webstore?

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djozz
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Does anyone have an experience with buying from Beijing Yuji's High CRI led webstore?

http://store.yujiintl.com/

The website is very good, with excellent information on high CRI lighting, and it looks like they sell what I would like to buy. But I can not find any customer reports on the internet, and a few bulbs plus shipping is expensive enough to worry about product quality/delivery/credibility.

power911
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dangit… their LEDs looked so generic

but it looks promising though

“Have you forgotten about all those who called you a Bringer of Woe and hunted you like an animal?”
“Normal humans don’t go around killing people and burning towns!”
“Don’t worry. I’ll go with you! So you just follow me and no arguing, okay?”
“Humans m

djozz
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Bump for the question of the OP.

Otanacious
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whew 4,000USD for 3kg of phosphor. At least you can buy some!

Billy X
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p>. But then again,3 weeks ago I thought cri was all and had never heard of R9,R12 etc.It is always the same problem,you want €15 of stuff(Cutter,Mouser…..)and they need €40 delivery for DHL/Fed Ex etc AND they insist on being part time customs officers,even if you are under the limit.Very not BLF :_( .

A possible solution,at least 4 or 5 of us,from the same/each continent, split a mini group buy by cost;merchandise ,delivery,and customs.After all,who needs 100 mini emitters(or springs Wink )but 20-25 at 50cents a piece.Of course that brings constraints,a forward voltage of below 4.2 limits the choice(I assume you are primarily looking at leds).If we could bring the unit costs under control,I would prefer to try a violet phosphor, ok 90 cents a unit .Any one else tempted? BTW my instincts say they know too much about what they are talking about to be “fast buck“sellers.The only worry is,does their practical skills match their theory,I hope so. Thanks to their website and this thread,I realized that those SMD numbers _all_SMD numbers,are just the length by width in mm(3528 is 3.5×2.8mm)Doh :~
Serifus
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Should try to get them to send a sample to hkj

djozz
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I took the gamble and placed an order for a 5600K 97CRI GU10 spot, a 4000K remote phosfor bulb and a bag of 3200K 90CRI 5mm leds. 25 dollar shipping Surprised. So far so good, I got confirmation emails and all. Keep you posted!

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I am very interested in the remote phosphor bulbs, please review them on arrival!

Aloha, Uli

djozz
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I received the package a few weeks ago, but did not get to this write-up before.

An unpleasant surprise was that I had to pay customs, so another 18 euro's was lost Sad All in all I would not have ordered two bulbs and a bag of 5mm leds if the shipping+customs were to be 46 dollars.

The packaging was very well done:

 

and this was inside:

I did not have more than a first look on the 5700K 97CRI GU10 spot, but here are some findings on the E27 4000K 95CRI remote phosfor bulb:

It is smaller than I thought, quite elegant:

The bulb does not show any flickering when photographed, unlike the IKEA led-bulb that was in the floorlamp before:

IKEA:   Yuji remote phosfor:

The white ceramic base of the bulb does get too hot to touch over time, but not so much that I get worried, many ledbulbs have that (including the above IKEA bulb). In my integrating sphere I measure 460 (djozz-)lumen after the bulb has warmed up for 10 minutes, which is in line with the factory-claimed 420 lumen.

I first put the bulb in the large floor lamp that is next to the couch. It gave a very good colour reproduction and the colour temp looked to be 4000K indeed, but it still felt weird. I then realised that the light was too dim for 4000K: light of that colour temperature (sun) is always very bright, if too dim it looks unnatural. The moment my girlfriend switched on the light later that day, she noticed the new type of light, said it was like hospital lighting and that the bulb had to go :bigsmile:

So it had to go into something smaller. I have a small worklamp for hobbying, and in there this bulb is just perfect: a good bright 4000K 95+ CRI soft flood, I'm really happy with that Smile  Smile

So how are the 3200K 90 CRI 5mm leds? They are wonderful too. I have not measured the output yet, but the warm colour and quality light is evident. I put nine of these in such a typical 9x5mm 3xAA cheapo flashlight and it became my bedside flashlight instantly.

The die projected on the wall with a lens, and a stereo image of the led:

 

Conclusions from this one order:

-For now I'm fan of Yuji leds, thusfar they look like quality products that perform to the specs, products that are hard to find elsewhere.

-The pricing seems reasonable

-Buying from their store is easy (Paypal)

-The number of products is limited and even then not everything is in stock.

-Packaging is good, shipping was fast (DHL, one week if I remember correctly).

-Shipping and customs are very expensive if only a few bulbs are bought, like I did. For larger orders it is no problem of course.

LED fan
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Hi djozz,

Thanks for posting your opinions on the lights from Yuji. I’m also thinking of buying their E27 light bulb and was searching the Internet for opinions and came across your post.

The only downside is the E27 bulb is only 420 lumens. Sad I’m hoping to get a high-CRI bulb at 1000 lumens or more.

Just to confirm, your E27 bulb is this one right: http://store.yujiintl.com/collections/high-cri-led-lights/products/high-... ?

Did you just buy one? In the link it seems it comes in a 4-pack for $68.

djozz
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LED fan wrote:
Hi djozz, Thanks for posting your opinions on the lights from Yuji. I'm also thinking of buying their E27 light bulb and was searching the Internet for opinions and came across your post. The only downside is the E27 bulb is only 420 lumens. Sad I'm hoping to get a high-CRI bulb at 1000 lumens or more. Just to confirm, your E27 bulb is this one right: http://store.yujiintl.com/collections/high-cri-led-lights/products/high-... ? Did you just buy one? In the link it seems it comes in a 4-pack for $68.

sorry about not answering sooner: yes, that seems the same bulb that I bought, and they changed the website a bit, so now you can only buy them in a 4-pack Sad

As an update: I have had that remote phosfor bulb in my hobbylamp for five months now, with on average an hour a day, but regularly evenings with many hours as well, and it holds up fine: gets hot but just works! I'm still very happy with it, it is great light to work with.

hank
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Yeek! this is a lot of emission in the blue-light-hazard range, for very little visible light benefit:

djozz
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And don't go outside! Look at the blue-light hazard range emission of sunlight! Tongue Out Wink

hank
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Yeah, it appears they are trying to produce a daylight (blue-sky-yellow-sun) emitter.
I’d guess they are driving it with a violet LED (the 410nm peak) and phosphors that emit in the green-yellow range.
It’s that leakage down around 400nm that matters and they show quite a bit more than I’d want placed near my eyes when indoors with pupils wide open.
Sunlight, well, your pupils restrict the light (better with age) and your lens ages as well.
The older you are, the less you need to wear eye protection: https://www.google.com/search?q=lens+yellowing+with+age

djozz
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The protection that your pupils provide fail if the ratio between near uv and the rest of the spectrum (especially green) is higher than sunlight, then your pupils are fooled and are more open than is good for you. In this led that ratio is much lower than with sunlight so your pupils instead do their job more than fine: if they are wide open, the 'blue hazard' is more than low enough.

hank
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hm, they say “-Full emission spectrum close to sun light” for the dual-LED strip
http://store.yujiintl.com/collections/high-cri-led-strips-ribbon/product...

Tempting, not sure how that description applies, maybe that’s with the blue emitters turned up full for the bluest color temperature.
I’d guess they’re talking about “daylight” meaning yellow sun plus blue sky, not just sunshine yellow.

frappu
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Hi, I’m new here.
Take a look at this
https://www.youtube.com/watch?v=L3LWXznJx_0
A practise explanation about the differences between standard cheap 100w cob led VS yuji 100w cob led

power911
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frappu wrote:
Hi, I’m new here. Take a look at this
A practise explanation about the differences between standard cheap 100w cob led VS yuji 100w cob led

fixing it up for you

I wish I could afford one of these light chip though
$83 is quite the price for a sunlight
I’d rather wait for afternoons

“Have you forgotten about all those who called you a Bringer of Woe and hunted you like an animal?”
“Normal humans don’t go around killing people and burning towns!”
“Don’t worry. I’ll go with you! So you just follow me and no arguing, okay?”
“Humans m

frappu
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Hi, a little update of my experience with yuji leds.
I have bought four of them from their website (100w cob 5600k), total cost was 359$ , shipping was fast (with dhl, about a week ) and I didn’t pay any customs taxes because yuji declared that the total value of the items was 10$ , so they are trustworthy.

djozz
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frappu wrote:
Hi, a little update of my experience with yuji leds. I have bought four of them from their website (100w cob 5600k), total cost was 359$ , shipping was fast (with dhl, about a week ) and I didn't pay any customs taxes because yuji declared that the total value of the items was 10$ , so they are trustworthy.

Wow, that was quite a purchase! I hope that the cobs will serve their purpose Smile

cajampa
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hank, check out Custom LED Spectrum Design by Yuji LED

Looks interesting, they may be able to formulate a phosphor mix for our after dark lights Smile

It would be nice to be able to use only a single led with the right spectrum & not have to use monochromatic leds or filters to block the unwanted blue & green parts of the spectrum.

I hope they can consider such an request, i do suspect it is really only for bigger commercial orders though, but they seem interested in the less populated part of the market with items like high CRI leds & multi temp led strips for example, so it may be possible to get them interested in the almost totally empty & hopefully future non blue polluting LED lights market.

I have’t asked them formally yet, but i will someday when i work out how to best propose it to them. If someone don’t beat me to it that is Wink

EDIT
Some of there products like the dual temp led strip would be perfect, for example a high CRI warm white & after dark spectrum LED “high CRI” or maybe full spectrum after 550nm is a better way to express it, or blue & green limited white LED perhaps.

hank
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> Yuji

Interesting! I filled out their inquiry form for their “custom simulator” software — which looks very promising.
Hope you will to — talk up BLF and the group design and quality control and group buy stuff people do here, and how it benefits builders/manufacturers who can go on with an improved product.

Maybe they’ll get involved.

It seems it’d be possible to combine a filter to block the critical wavelengths — somewhere in the 400-500nm range, roughly.

Aside — please do take notes and keep track especially of OLDER mentions of working on this problem. I know at least one LED company claims to have a recent patent on the idea of a low- or no-blue-light source (the US patent office is pathetic, about as good as the Australian patent office that, some years back, gave a patent on the wheel — and the way to challenge that kind of thing is to show “prior art” existed as public knowledge that makes a patent invalid.

https://www.newscientist.com/article/dn965-wheel-patented-in-australia/

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http://store.yujiintl.com/collections/high-cri-led-lights/products/vtc-s...

For a 10W bulb, is the 440lm output a bit low(ish) or does it really take that much power from output to get spectrum right?

djozz
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CheapThrills wrote:
http://store.yujiintl.com/collections/high-cri-led-lights/products/vtc-s... For a 10W bulb, is the 440lm output a bit low(ish) or does it really take that much power from output to get spectrum right?

Not sure about household bulbs, but for a flashlight, 44lm/W is not so bad if it is 90+ CRI. My most efficient cool white low CRI flashlight runs at betwern 90 and 100 lm/W. A stock sk68 clone is under 40 lm/W.

Serifus
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I have to wonder how difficult it would be to do something similar to what they are doing with the led filament bulbs that have popped up recently https://www.youtube.com/watch?v=H_XiunR-cAQ

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djozz wrote:

CheapThrills wrote:
http://store.yujiintl.com/collections/high-cri-led-lights/products/vtc-s... For a 10W bulb, is the 440lm output a bit low(ish) or does it really take that much power from output to get spectrum right?

Not sure about household bulbs, but for a flashlight, 44lm/W is not so bad if it is 90+ CRI. My most efficient cool white low CRI flashlight runs at betwern 90 and 100 lm/W. A stock sk68 clone is under 40 lm/W.


ahh, ok thanks!
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hank wrote:
Yeek!  !  

 Excellent spectrum!

It's for VTC 5730 led's or for lamp ? What spectrometer you used ?

Anyone use Yuji  BC Series High CRI MCPCB LED 24V Modules ?

 

hank
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Evgeniy, you asked where that spectrum comes from.

Go back up the thread to where I posted that spectrum, originally (not the copy you reposted)

Click on the one I posted, and it will show you the page where the image comes from.
It’s their spectrum from their web page, I did not create it.

(when you post an image link using the little “sunset” icon above the text entry box, it lets you first post the link to the image, and then optionally post the link to the source page, that ‘s what I did there)

(I do sometimes post spectra I captured using this: https://publiclab.org/wiki/spectral-workbench

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hank wrote:
and it will show you the page where the image comes from.

Thanks.  (Image removed from Yuji site, 404, but found by web.archive.org.)

you use Yuji led modules ?

hank
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Odd, I got to that page earlier this morning.

Nope, curious about them but not up for ordering stuff I don’t know much about.
If they had something like the Luxeon PC Rebel Amber with a bit of phosphor added to improve color rendering, that would be interesting.
But “no blue_ is what I’m mostly looking for that’s hard to find.

hank
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Interesting tidbit — even blind people who lack rods and cones still respond to the blue range by having their body clock reset, among other responses:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2151130/

Quote:
…. photosensitive retinal ganglion cells (pRGCs) that are most sensitive to short-wavelength (∼480 nm) blue light and remain functional in the absence of rods and cones [8–10]. We examined the spectral sensitivity of non-image-forming responses in two profoundly blind subjects ….

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