Seoul P4 initial Evaluation- Production LEDs

[IsaacHayes]

Wow, that sure does shift a lot!!! I'm guessing it's their phosphor that's weird.

Nereus: It could be just a high Vf sample, one would need to test several P4's to find out. I have a XRE that is way higher than my other ones on VF, so it could just be lottery. Another thought in discussion with Newbie is the bond wires could be smaller on the P4 than the XRE, and that might cause some resistance. But we don't know without further testing.


Newbie: A bit off-topic, but is anyone using the nm sized particle YAG phosphor yet?

 

[NewBie]

Issac,

I don't think any of the recent phosphor developments have made it into production products yet, it will be very interesting to see those get into the mix, on top of everything.

I fiddled around a bit more with my movie camera, and used the white balance to set a neutral perfect white at 700mA. I then varied the current up to 1100mA and down to 400mA. Unfortunately, my video camera has very poor latitude, and does not do a good job of capturing the lighter and darker areas so you would be able to see how the various tints in the beam of the Seoul P4 shift at different current levels.

Links to the videos:
http://www.molalla.net/~leeper/sp4twb.wmv

Zoomed on on the hotspot:
http://www.molalla.net/~leeper/sp4zoom.wmv


I added a high resolution version of the zoomed in hotspot, which shows things much better, worth the download, imho (3MB):
http://www.molalla.net/~leeper/sp4higrs.wmv


.

 

[NewBie]

Well, I ran a second Seoul P4 thru the same drive levels, it doesn't get nearly as blue, but still shifts around.

The more and more I fiddle with these parts, the more I realize the consistency is not like the Luxeons.

Personally from what I see so far, if I were buying the Seoul P4 in a flashlight, I think myself, I'd really want to try out a batch of them, and choose the pick of the litter, unless it was a 10 dollar flashlight (and then, I'd still be tempted).

So, from what I'm seeing out of my first batch... For some, it is possible that they may get a premo choice part, and they will feel they are as good as a Luxeon (or better, since it is a lot brighter than the Luxeon). Others may get not so awesome of a part, and they won't be all that happy about it, especially those that have some conerns over tint and tint variation. Right now, about the only idea I can think of, is to ask specifically for the full ranking of the parts that comes off the reel, Flux, Tint, and Forward Voltage for the flashlight they are put in- or to ask what tint bin the flashlight is in at its rated current- like SYN @ 1100mA (roughly like LumiLEDs YA) and then what bin it falls in at it's dim current, like SUM @ 50mA (LumiLEDs UM bin).

For those that haven't seen it yet, due to tint requirements of customers, LumiLEDs has moved to tighter bins, back in May of 2006, so the chart above may be a surprise.

I understand that Seoul Semiconductor offers sub-bins, however, I've never been able to buy a single bin. The ones I've gotten so far are by Kelvin temp (6500K), which leaves you pretty wide open. Possibly if one was able to purchase a single bin, the variation from part to part would be less, and I think if I was buying an expensive light with the Seoul P4, I'd really like the bin stated.

I'm not sure at what current Seoul bins the P4 at but when I get them directly from Seoul, on the package, you will see USW0H, where U = flux 91-118 (LumiLEDs 87.4 to 113.6), SWO basically equals LumiLEDs WO color bin, and H is the same as LumiLEDs Vf H bin, but 0.03 Volts lower.

I'm currently unsure at what current Seoul bins these at, but since the datasheet has it's Electro-Optical characteristics stated at 350mA, possibly it is done there. They also show the Relative Light Output vs. Junction temperature @ 350mA. Unfortunately, at other currents, white LEDs only generally track, and it isn't possible to specifically nail down exactly what the LED is going to do at other currents.

When soldering the slug down, if the part has not been in a sealed dry atomsphere, and they have been outside the sealed dessicant package more than 1 week, you will want to bake the parts for 10-12 hours at 60C before soldering the slug down. When washed, they recommend Isopropyl Alcohol. They recommend that if you are storing them for more than three months after shipping from SSC, that you store them in a sealed container with dry Nitrogen. Long term exposure to sunlight or occasional UV will cause lens discoloration. Avoid leaving fingerprints on the silicone resin lens. And they do not recommend covering the silicone resin lens with another resin.

Possibly, with higher dollar lights, we could get the makers to provide a tint variation plot with current or something. It would not need to be exact, only what the light typically does. IMHO, this would be helpful for these parts.


Meanwhile, I'm going to work on a video with a different Seoul P4 part to try and show you what I am talking about.


Overlayed bins:

.

 

[Anglepoise]

First let me join others above and thank you for all this hard work you have done. Most commendable.

Now in regards to your comment below.
Am I correct in assuming that like Lux emmiters, there is no bin info stamped on each individual P4 or XR-E emmiter ( my XR-E samples were unmarked )?

As many of us will be purchasing in under 10 quantities, we are all going to have to rely on the honesty of the vendors who are selling from reels. This is an area where the LUX III consistency was most helpful and if we start to see 'high grading' by vendors lower down the supply chain, the word 'lottery' will have to be changed to something more along the lines of 'dishonesty'. I hope I am wrong.

So, from what I'm seeing out of my first batch... For some, it is possible that they may get a premo choice part, and they will feel they are as good as a Luxeon (or better, since it is a lot brighter than the Luxeon). Others may get not so awesome of a part, and they won't be all that happy about it, especially those that have some conerns over tint and tint variation. Right now, about the only idea I can think of, is to ask specifically for the full ranking of the parts that comes off the reel, Flux, Tint, and Forward Voltage for the flashlight they are put in- or to ask what tint bin the flashlight is in at its rated current- like SYN @ 1100mA (roughly like LumiLEDs YA) and then what bin it falls in at it's dim current, like SUM @ 50mA (LumiLEDs UM bin).


.

 

[McGizmo]

......
Personally from what I see so far, if I were buying the Seoul P4 in a flashlight, I think myself, I'd really want to try out a batch of them, and choose the pick of the litter, unless it was a 10 dollar flashlight (and then, I'd still be tempted).

So, from what I'm seeing out of my first batch... For some, it is possible that they may get a premo choice part, and they will feel they are as good as a Luxeon (or better, since it is a lot brighter than the Luxeon). Others may get not so awesome of a part, and they won't be all that happy about it, especially those that have some conerns over tint and tint variation. Right now, about the only idea I can think of, is to ask specifically for the full ranking of the parts that comes off the reel, Flux, Tint, and Forward Voltage for the flashlight they are put in- or to ask what tint bin the flashlight is in at its rated current- like SYN @ 1100mA (roughly like LumiLEDs YA) and then what bin it falls in at it's dim current, like SUM @ 50mA (LumiLEDs UM bin)

........ I think if I was buying an expensive light with the Seoul P4, I'd really like the bin stated.

..............

Possibly, with higher dollar lights, we could get the makers to provide a tint variation plot with current or something. It would not need to be exact, only what the light typically does. IMHO, this would be helpful for these parts.

.......

IMHO, some ideas and suggestions here are so unrealistic that I am dumbfounded!

Hypothetically, let's suppose that a company like SureFire decides to switch from Luxeons to the Seoul P4 in some of their models. Presumably the switch would be based on a typical doubling of flux and efficacy in comparison to the Luxeons. SureFire specs are typically given on flux output and runtimes. There is no information presently given on tint, color temp and certainly no bin information provided. Bin information essentially takes one SKU and turns it into a number of new SKU's. :green:

Now, if one shops at brick and mortar, it is conceivable that a dealer might allow for on sight evaluation of all of the lights presently in inventory if the lights are not packaged with a seal or wrapper. The dealer may decide if every customer wants to test every light that it is too much trouble stocking these lights.

If the light is bought via mail order or over the internet and customers are of the opinion that they can and will evaluate each light and return it until a satisfactory unit is found, I doubt these lights will be offered for any length of time.

Even if the manufacturer were to go to the trouble of providing a specific data sheet with each light and include its LED bin information, the variations within a specific bin are real and measurable and noticible.

" Dear Mr. SureFire dealer,

Although the light I just purchased from you may well provide the lumens stated and run for the time period claimed in the spec sheet, I find the tint of this light unacceptable. I want something with a warmer tint and less variation throughout its beam and I want it to hold constant regardless of the level output I have selected to run it at. Please replace this light being returned with one compliant to my desires.

- Unsatisfied Customer
Member of CPF"

"Dear unsatisfied customer,

As a Surefire Dealer, I have had to replace previous SureFire LED lights due to what you CPF people call pee green tints. This has been a real hassle at my end and good cause to consider droppng the line or at least avoiding sales to customers bent on using their own criteria, above and beyond the manufacturer's stated claims, to determin the acceptability of the product. Please accept a refund on this latest purchase and don't buy a LED light from us again as we make no claims to be able to satisfy your expectations.

- SureFire dealer, at least for the moment.... "

Now this is all hypothetical and of my creation.

 

[McGizmo]

Anglepoise,

I think the realistic approach to take regarding the Seoul P4 LEDs is that of expecting tint variations at all levels; among the LED's themselves, within the beam of a single LED and with a change in drive current.

I don't doubt that there will end up being descrimination of the LED's based on bin information, when provided. This may be at the manufacturer level to OEM. This may be at the distributor level to a customer worthy of bin issue consideration and this will likely be at the CPF level where knowledge of specific bin information is brokered to those willing to pay premium.

Terms like "unrealistic expectations" and "preposterous" come to my mind in consideration of these P4's on certain levels of differences among them.

The P4's have visual and measurable variations. If one has the means of identifying these variations and an ability to buy and sell these based on these variations, so be it. If not and if these variations are of a concern, one solution is to simply avoid the P4's. :shrug:

 

[NewBie]

Am I correct in assuming that like Lux emmiters, there is no bin info stamped on each individual P4 or XR-E emmiter ( my XR-E samples were unmarked )?

As many of us will be purchasing in under 10 quantities, we are all going to have to rely on the honesty of the vendors who are selling from reels. This is an area where the LUX III consistency was most helpful and if we start to see 'high grading' by vendors lower down the supply chain, the word 'lottery' will have to be changed to something more along the lines of 'dishonesty'. I hope I am wrong.

The XR-E does NOT come in a STAR format from CREE, just the emitter by itself. As such, if you get them from authorized distributors, they will come in sealed bags marked with the exact tint bin and the intensity bin. Beyond that, you will need to trust the resellers, and the companies they are using to mount the parts, the materials used, and the process involved.

IMHO, some ideas and suggestions here are so unrealistic that I am dumbfounded!

Hypothetically, let's suppose that a company like SureFire decides to switch from Luxeons to the Seoul P4 in some of their models. Presumably the switch would be based on a typical doubling of flux and efficacy in comparison to the Luxeons. SureFire specs are typically given on flux output and runtimes. There is no information presently given on tint, color temp and certainly no bin information provided. Bin information essentially takes one SKU and turns it into a number of new SKU's. :green:

Now, if one shops at brick and mortar, it is conceivable that a dealer might allow for on sight evaluation of all of the lights presently in inventory if the lights are not packaged with a seal or wrapper. The dealer may decide if every customer wants to test every light that it is too much trouble stocking these lights.

If the light is bought via mail order or over the internet and customers are of the opinion that they can and will evaluate each light and return it until a satisfactory unit is found, I doubt these lights will be offered for any length of time.

Even if the manufacturer were to go to the trouble of providing a specific data sheet with each light and include its LED bin information, the variations within a specific bin are real and measurable and noticible.

" Dear Mr. SureFire dealer,

Although the light I just purchased from you may well provide the lumens stated and run for the time period claimed in the spec sheet, I find the tint of this light unacceptable. I want something with a warmer tint and less variation throughout its beam and I want it to hold constant regardless of the level output I have selected to run it at. Please replace this light being returned with one compliant to my desires.

- Unsatisfied Customer
Member of CPF"

"Dear unsatisfied customer,

As a Surefire Dealer, I have had to replace previous SureFire LED lights due to what you CPF people call pee green tints. This has been a real hassle at my end and good cause to consider droppng the line or at least avoiding sales to customers bent on using their own criteria, above and beyond the manufacturer's stated claims, to determin the acceptability of the product. Please accept a refund on this latest purchase and don't buy a LED light from us again as we make no claims to be able to satisfy your expectations.

- SureFire dealer, at least for the moment.... "

Now this is all hypothetical and of my creation.

Don-

I am not sure if you have noticed, but CPF'ers already have a long history of returning Surefire flashlights for tint issues, and it has been mentioned quite a number of times. Surefire even replaces them for tints, and that too is documented here on CPF.

The advantage that modders have, is they can select the parts used for their mods, and maybe this is the approach that should be used with the P4, depending on the current you are driving them at (since they shift so badly).

I dunno, it is just an idea on how to deal with the Seoul P4 parts- do whatever you want, I'm sorry if you take my ideas personally. We have a long history here on cpf, on custom lights and mods, of folks stating or buyers wanting to know the brightness and tint bins, as it is important to some folks.

You yourself have often mentioned you prefer the X1 bins for over-emphasizing green plants and such in the outdoors, myself, thats not what I am usually looking for, but actually what I prefer not to see- since it is everywhere, and I don't go out hunting pine or fir trees. To each his own, I'm definitely not saying you are wrong, as only you know what you prefer best and everyone is different.

Another idea, if I didn't mention it, is just to utilize the Seoul P4 in single level lights, selecting the bin needed, that get you to the color tint you want to be at, say at 917mA, 825mA, 660mA or whatever level you are going to drive the LED at.

I'm working on finishing up a video from another Seoul P4 right now, off the same reel strip, you be the judge of the differences... I'll get it up shortly.

 

[McGizmo]

Newbie,
I plan to use the P4's in some builds because of their flux and efficacy and dispite their tint variations. Same case with the Cree XR-E's. With both of these LED's, I have seen variation in tint within a specific bin to make me think that knowledge of the bin itself is not enough to insure knowledge of what you will get when you fire up the LED.

Your ideas of how these LED's should or could be implimented are your ideas. You can share them with others and you can impliment them in a light of your design and offering. You can do what ever you choose to do with your ideas. Obviously.

I have the option of considering your ideas for their merits and electing to ignore them if I find them unrealistic or unviable.

When I finally have some lights hosting the P4's to offer, I will attempt to provide all possible and pertinent disclaimers and be clear on what these lights are about. I will be clear that they do not comply with the Newbie Seal of Approval nor should one have any expectations that they do.

Maybe it's time to stop telling us and time to show us the way? :shrug:

EDIT: A history of behavior or action doesn't make such behavior good or bad. Repeating history is history repeated. Out of curiousity, should the customer provide advance notice to the dealer when they plan to use a method of evaluation of a products compliance that goes beyond stated claims of the product made by manufacturer or dealer?

 

[NewBie]

Don-

I am not telling anyone they have to do anything at all. I'm just offering up ideas on ways of dealing with short commings.

I am not motivated to make profit by making flashlights, selling flashlights, nor am I associated with any company that makes flashlights, or invested in such. For me, this is a hobby, and I intend upon it remaining that.

If I were to start making and selling flashlights, then it would be a job, not a hobby, and imho, much less enjoyable. Personally, I actually enjoy testing things, and finding out the results, as well as designing things, and I find manufacturing things to become a chore after a while. At the point where I'd begin making flashlights, my opinions would also probably become highly biased on what I was trying to sell at the moment, and I'd seriously start having to look at myself in the mirror a lot, a most definite catch-22 situation.

I never asked you to take any of my ideas as absolutely correct, I am just tossing out things for folks to consider.

Lets take your preference for X1 bins. Yes, they are yellow-green when compared to white. So what. Some folks on CPF prefer XO, or WO bins. Other folks really prefer YO and VO bins. To each his own, it is not my concern at all. To just say a light has tint, and to say it has no importance, except yes it has tint, is a tad odd, imho. You have had a long history of preference for the X1 bin. So, even you yourself are thus saying tint is important. Furthermore, you yourself have stressed how much more color rendering the X1 tint bin offers, and a few others support that opinion. Thats fine, nothing wrong with that, but tint is quite important to some. It is in my personal opinion a dis-service to say that tint has no importance or that there should be no consideration for the same.

Anyhow, I'd recommend that we take your personal preferences and such to PM or email, and get back on the topic.


Anyhow, here are the results from a second LED over the same range. Both of these Seoul P4 LEDs are actually from the same reel strip, in fact, side by side in the strip.

First LED here:
http://www.molalla.net/~leeper/sp4higrs.wmv

Second LED here:
http://www.molalla.net/~leeper/sp4t2nd.wmv

 

[X Racer]

And the tint debate is alive and well... I don't see an end in sight to the tint debate.

As a consumer, it would be great to be able to purchase only the best of the best as far as bin codes go.

But then, as a manufacturer, what are they supposed to do ? Purchase 200 units of a certain bin, hand select the 50 units that meet the criteria for use ? What of the other 150 units that don't make the spec ? Do they charge you the cost of 4 LEDs to make up for the three that get scrapped ?

 

[easilyled]

And the tint debate is alive and well... I don't see an end in sight to the tint debate.

As a consumer, it would be great to be able to purchase only the best of the best as far as bin codes go.

But then, as a manufacturer, what are they supposed to do ? Purchase 200 units of a certain bin, hand select the 50 units that meet the criteria for use ? What of the other 150 units that don't make the spec ? Do they charge you the cost of 4 LEDs to make up for the three that get scrapped ?

I suppose what they could do concerning output is to have a base target
for output. They could get a light-metre reading for each light and then
sell the ones that exceed the target-range for a higher price, sell the ones
that meet the target-range at the intended price and sell the ones
that fail to meet this target-range at a lower price.

I could see this type of disclosure causing problems though as most who
can afford Ti McGizmo lights are going to prefer spending more for the higher
outputs and therefore there may be a whole lot of lights left unsold. :shrug:

 

[McGizmo]

Newbie,
This is your thread and I will bow out now. No need to waste either of our time in PM's. Enjoy your hobby.

 

[NewBie]

And the tint debate is alive and well... I don't see an end in sight to the tint debate.

As a consumer, it would be great to be able to purchase only the best of the best as far as bin codes go.

But then, as a manufacturer, what are they supposed to do ? Purchase 200 units of a certain bin, hand select the 50 units that meet the criteria for use ? What of the other 150 units that don't make the spec ? Do they charge you the cost of 4 LEDs to make up for the three that get scrapped ?

Some people do purchase the best of the best bin tints, and we have folks making a profit here on CPF by selling them by tint, output, and even forward voltage. Thats what threads that say UXOH and XX1S are about.


I have no idea what folks will do, IMHO the Seoul P4 has really opened up the same old issue we had many years ago with the Luxeons when they first came out. Craig from LEDMuseum even coined the term pee-green or whatever it was. What I see is new with the Seoul P4, is that I am seeing extra tint shifting at various drive levels. This could be a big issue in low output dual stage drive lights, maybe one could get a bin that it is just bluish when you want punch, and yellow when you just need a tad of light (splitting the difference). Unfortunately, when you drive white LEDs hard, they generally shift a little blue, and when driving them lightly, they shift yellow. The Seoul P4 seems to do more of this than other LEDs I've worked with.

Maybe folks could apply the method that Henry did with the ARC4 and HDS lights, to the Seoul P4, where you pull a few drive techniques to hold the tint more constant. Not just a PWM or CC thing alone. Definitely something to consider.

I suppose what they could do concerning output is to have a base target
for output. They could get a light-metre reading for each light and then
sell the ones that exceed the target-range for a higher price, sell the ones
that meet the target-range at the intended price and sell the ones
that fail to meet this target-range at a lower price.

I could see this type of disclosure causing problems though as most who
can afford Ti McGizmo lights are going to prefer spending more for the higher
outputs and therefore there may be a whole lot of lights left unsold. :shrug:

Interesting idea, I imagine that could work, that is kind of what HDS did with their EDC60, EDC60GT, EDC60XR, and EDC60XRGT, which seemed to work for them just fine. It would also allow the maker to get extra profit off the premium parts.

Example here:
http://www.hdssystems.com/EdcUltimate.html


Well, I'm done with this video comparision testing for now, until I get one soldered directly down to a plate of copper and mount it on a CPU heatsink. Here is a third LED for comparison against the first two:


First LED here:
http://www.molalla.net/~leeper/sp4higrs.wmv

Second LED here:
http://www.molalla.net/~leeper/sp4t2nd.wmv

Third LED here:
http://www.molalla.net/~leeper/sp4t3rd.wmv


.

 

[IsaacHayes]

I like LED #2! doesnt shift much at all.

EDIT it does shift, more to like Y0 at the end, but on my monitor doesnt look like a straight blue led at the end, LOL!

 

[EngrPaul]

Newbie,

Please clarify, you're testing T-Binned P4's, right?

Thanks in advance.

 

[IsaacHayes]

I think he said they were U's.

I'm not sure at what current Seoul bins the P4 at but when I get them directly from Seoul, on the package, you will see USW0H, where U = flux 91-118 (LumiLEDs 87.4 to 113.6), SWO basically equals LumiLEDs WO color bin, and H is the same as LumiLEDs Vf H bin, but 0.03 Volts lower.

 

[EngrPaul]

His one chart showed a T in the part number... I'm always confused by what I see.

 

[NewBie]

EngrPaul,

I am testing the T bin Seoul, as that is all I have available at the moment. I have not seen U bins yet.

 

[EngrPaul]

Thanks NewBie. Let's hope they perform better.

 

[NewBie]

Well, I went down to Fry's and bought an overkill heatsink.

I then soldered a fourth Seoul P4 to the same 0.165" sheet of Copper that I have some CREE XR-E LEDs soldered on.

I then wired the LEDs in series to assure that each received exactly the same current, and placed a meter in series with them.

Before we get into further testing, I just want to say that not every one of these shifts the same, and you can see the results in the videos from previous posts. Some start tinting blue at a low current and some start tinting blue at a higher current, it is almost like there is a knee.

The previous tests had the Seoul P4 thermal epoxied down to a large solid aluminum rod, definitely more thermal sinking and lower thermal resistance path down the length than you'd see in a typical setup. Soldering and heatsinking is an attempt to see if agressively lowering the thermal resistance to hold the die temperature extremely low would reduce the color shift.

Anyhow, enough with the words, here are the pictures, with a meter showing the current going thru the two LEDs (wired in series):

I have a video of the same test that I am working on right now, I will post it shortly.