Cree XR-E vs. Seoul P4

Hi,

In the moment I read a lot of the power of the seoul P4 LED over a Cree XR-E. I woundered what´s the truth behind that. So I tried both with comparable reflectors with an astonishing result.

I had some XR-E P4 in stock with (only) around 85lm/W while the P4 is the best binning with 100lm/W claim. The reflector I used is in both cases a McR-27 (special XR-E and P4 version) that should get the best out of both emitters. Both reflectors have nearly the same heigth, so they should be able the catch the same angle of light.
The image/hotspot I got with both are nearly the same regarding the size of the hotspot. But what´s abount the more interesting lux measures?

Well the old XR-E P4 binning gets up to 7.900 lux. Now I tried the seoul P4 with its reflector friendly beam pattern and like everybody I expected some more lux on the clock.... but nada.
The seoul P4 with its 100lm/W on paper achieves the SAME lux measument from around 7.900 lux BUT with less sidespill (of course). :thumbsdow

Besides that the seoul look clearly more blueish at 1Amp with poorer color redering.

Are there others out there that can confirm that observeration and share their results with a McR-27? For me a Seoul P4 looks like a poor choice if you HAVE one ;-)

greets
MikeRD03

I thought they needed different reflectors. Do they not?

DIfferent reflectors with different LED's give different results. Also, Lumens/=lux

The reflectors (should) differ only by 0.25mm (?) but it does matter...

My CM Cree'd Chameleon at 1 amp to led reads 5112 lux corrected to 1 meter (lux taken at 6 meters). My Seoul'ed VIP at same mA to led, that uses the same reflector as the Chameleon reads 6084 lux. Not much difference. The Seoul'ed VIP put out more light (bounce with lightmeter) than the Cree. The beam shape of the VIP is not as defined as the Cree'd Chameleon, and is actually wider.

Where the Seoul really shines is applied to a larger reflector, in this case a 3" reflector called the BBH, achieving 42,840 lux. The Cree'd Chameleon was not tested in this reflector, as the threads do not match, and I am sure that the angle of the Cree's beam would not work well in a reflector that was optimized for a lux III.

Bill

Compare the p4 vs. the XR-E in a Mag reflector and I guarantee you will see a difference.

Nitrox, how so different? My other Chameleon has not been Cree'd, or Seoul'ed and I have the Chamelhead head with a 2" D mag reflector. Which would work better?

Bill

I have been thinking of this very mod. A Seoul under the 3" BBH will be nothing short of amazing.

Are the numbers with the stock driver?

OK down to business.
I have several lights in both.
The seoul seems to emit more light.
I have a 27LT with a seoul emitter which produces 5500lux at 1 meter.
I also have a PD with a seoul which in the mizer mode which is somewhat brighter than mu U-Bin Lux3.

I have a PD with the A Cree which is very bright.

I could make some measurements I suppose.

Generally for the same current the seoul emitter has a higher output.
The real beauty of the seoul is the idea that is is a very efficient emitter, There is no real need to drive it to the MAX. You can get plenty of light out of from a seoul emitter and still have it run cool. I think that is pretty neat.

The other issue is the cree emitter produces RINGS. if you use an optic the projected image is less than perfect.

Go with the seoul.
Yaesumofo

Bullzeyebill said:

My CM Cree'd Chameleon at 1 amp to led reads 5112 lux corrected to 1 meter (lux taken at 6 meters). My Seoul'ed VIP at same mA to led, that uses the same reflector as the Chameleon reads 6084 lux. Not much difference. The Seoul'ed VIP put out more light (bounce with lightmeter) than the Cree. The beam shape of the VIP is not as defined as the Cree'd Chameleon, and is actually wider.

Where the Seoul really shines is applied to a larger reflector, in this case a 3" reflector called the BBH, achieving 42,840 lux. The Cree'd Chameleon was not tested in this reflector, as the threads do not match, and I am sure that the angle of the Cree's beam would not work well in a reflector that was optimized for a lux III.

Bill

Click to expand...

Bullzeyebill said:

Nitrox, how so different? My other Chameleon has not been Cree'd, or Seoul'ed and I have the Chamelhead head with a 2" D mag reflector. Which would work better?

Bill

Click to expand...

The Cree is horrible in a stock mag reflector. The P4 is not bad at all.


Mac

+1 Seoul

The P4 bin has ranges of Lumen/Watt, you might have gotten one that is on the lower end of the P4's efficiency range.

cmacclel said:

The Cree is horrible in a stock mag reflector. The P4 is not bad at all.


Mac

Click to expand...

What Mac said...

As you see most everyone agrees that the Seoul LED is much better for a reflector. I have tried both the Cree and Seoul LED in the Mag reflector, the Seoul wins easily!

Well guys, I tested both LED in a quiete narrow McR-27XR and a McR-27S. Both are opimized for their LED typ but both are looking quiete the same. I think the amount of surface that reflects the light ist just the same. So you can compare both LED quiete good, imho.

Ich got with both reflectors around 8.000 lux out of 27mm diameter but the Cree has a significant better sidespill with its build-in lens. When I try a combo of lens and reflector it goes to Cree with over 10.000 lux again 9.000 lux with seoul.

So when I calculate a better Cree bin like the Q3 with 100lm/W a seoul is simply outperformed in my setup. btw I tested more than one LED of each typ to reduce the bin dispersion.

But I can imagine that these numbers can go towards the seoul with bigger reflectors.

Nevertheless ist quiete interesting and it seems that seoul lumen <> cree lumen !?.

cheers,
MikeRD03

After testing just one example of each, I don't think that's enough
to generalise or draw any firm conclusions.

Remember each led has quite a wide range of output from min to max
in its given bin and the lottery is still at play.

easilyled said:

After testing just one example of each, I don't think that's enough
to generalise or draw any firm conclusions.

Remember each led has quite a wide range of output from min to max
in its given bin and the lottery is still at play.

Click to expand...

There is HUGE differences. I have built a few multi LED's using the cree's and on low almost all of them show very different brightness and tint levels.


Mac

@cmacclel
I´ve tested four Cree XR-E with the same reflector and each was between 7.800 and 8.000 lux. Cree has a quiete narrow binning so that this should be real numbers.
The binning of seoul ist not that hard like cree but I´ve taken the best binnung that should have in worst case at least 91 lumen/W and the Cree with P4 have 90 lumen/W in BEST case so only based on this numbers the seoul P4 has to be better but it is not!
Now I wonder why - is there anybody out there who tested a 100 lumen P4 with the McR-27S? Which lux measures are possible at 1m?

Perhaps someone sold me the cheap 80 lumen P4 as the 100 lumen version?!

cheers
MikeRD03

This may be of interest

Elly / CREE / Seoul mods rt's

https://www.candlepowerforums.com/threads/153283



I get the impression that Seouls may be better suited to incandescent mods, where the proud Seoul led may better fit the incan reflector ?

Generally for the same current the seoul emitter has a higher output.
The real beauty of the seoul is the idea that is is a very efficient emitter, There is no real need to drive it to the MAX. You can get plenty of light out of from a seoul emitter and still have it run cool. I think that is pretty neat.

Click to expand...

I belive one poster claimed that the Seoul has a slightly higher forward voltage, so while it emits more light at higher current, the lumens per watt are a lot closer.

The other issue is the cree emitter produces RINGS. if you use an optic the projected image is less than perfect.

Click to expand...

This is true, although for the time being the main reason I am using Cree for just about everything is that I can get P4 Crees for about half the price of U-Bin Seoul ($7.50 shipped vs around $14 shipped).

yaesumofo, regarding your question about VIP and high lux with BBH (3"), the numbers are with the stock driver with high level biased to 1 amp to the led. Interesting that the medium level, which is about 350mA's to led, reads almost exactly 1/2 lux of high level reading.

Bill

Different LEDs for different application here.
The XRE have a tighter beam so you can only do so much with reflector.
Where the S-P4 have a more lambertian beam so it rellies more on the reflector.

IMHO, lights with a 15mm or smaller openning would do best with an XRE while those @ 18mm or larger would fair better with S-P4.

Again its all depend on what beam distribution you want.