LED Comparisons

[sweetlight]

Hey, I know Cree is now state of the art technology and gives about twice the output of Luxeons. can someone give me a basic, laymans description of the differences between Cree, Luxeon and high flux? Are there still any advantages for Luxeon or any other technologies? Whiter light etc. I'm still kinda new to this, Thanx!

 

[Search]

Before you get flamed for not searching, even though that would be hard to word.

If you don't have anything nice to say.. hit the back button.

Someone will be kind enough to answer this peacefully, everyone else just clogs up the thread.

 

[yellow]

you can check th stickies and welcome mat.

for Your questions, You are roughly right:
there is no big electrical difference for white led, they all run on - more or less - identical current and voltage

as to brightness: correct, the new ones (Cree XR-E and Seoul P4) give roughly double of old Luxeons, at same current and voltage. Refer to binning for more info

color: thats the tint of the individual led, ranges from yellow to blue, I'll search for a good explaining thread in seconds
... generally newer led tend to be more stable, with - again - a plus for the cree, where the bins and tints are the smallest range, while a single Luxeon or Seoul bin usually covers several of Cree's bins.

[edit] check this thread here: http://www.candlepowerforums.com/vb/showthread.php?t=156772
shows the individual tint range of a good number of led [/edit]

Also the newer Luxeon rebel is considered here to be almost as bright as XR-E and P4, and to be more on the warm output side.
I just can type: got a few identical Rebel using lights and their outputs ranged from white (not warmer white) to ugly blue, with most of them on ugly blue. Unfortunately was nto able to order a special tint, ...
5 Rebels surely is not scientifically correct, but I have learned my lesson - stay with Cree.


Then there are the new multiemitter led, who house several emitting die in "one led".
Seoul P7 being 4 individual led, as is Cree MC-E and the 4-die Osram Ostar, then there is a 6-die Osram Ostar and several other makes
(the Seoul and Cree, again, giving about double the light at same power)
These are

 

[saabluster]

Before you get flamed for not searching, even though that would be hard to word.

If you don't have anything nice to say.. hit the back button.

Someone will be kind enough to answer this peacefully, everyone else just clogs up the thread.

Experienced this a bit yourself lately or something? You haven't been here for long. When you've seen the same thread started for the billionth time it gets kind of old and that is why you see people telling you to search first. That said sometimes when you search you would have to search through for weeks just to find what you want.

Hey, I know Cree is now state of the art technology and gives about twice the output of Luxeons. can someone give me a basic, laymans description of the differences between Cree, Luxeon and high flux? Are there still any advantages for Luxeon or any other technologies? Whiter light etc. I'm still kinda new to this, Thanx!

Cree gives about twice the output of the old Luxeons. The newer rebels and K2s are OK and are generally about 80%(off the top of my head) the output of a Cree top bin to top bin. The Luxeons have had in the past better beams(fewer artifacts) than the Cree(XR-E) due to the lack of the metal ring as surrounds the Cree LED die. This has now been rectified with the release of the new XP-E/XP-C. The downsides of these however is the small size that makes them hard to work with(same problem with Luxeon rebels). Although Cree wins the Lux wars and even has better CRI than the SSC for example when comparing "normal" phosphor leds, SSC has a version of the P4 that is high CRI and Cree does not have any high CRI LEDs. The high CRI LEDs are nothing short of a revelation. The two big ones are the SSC P4 high CRI and Nichias 083 high CRI with the latter having less output than the SSC but reportedly slightly better CRI.
Then there are the four die LEDs like the Cree MC-E and SSC P7. Both use Cree's dies but the package varies greatly. The P7 is said to work better in reflectors as it has fewer artifacts from the gaps in the four dies but it is a relatively large package that does not fit very well in a small reflector and is not easy to swap into old lights without major reworking of the reflector. The Cree MC-E has the same size package as the single die XR-E and can easily be swapped into lights that were made for the XR-E. It is reported to have more artifacts than the P7 due to the higher magnification of the dome that covers the dies. But it has individually addressable dies and slightly higher CRI.
Well that is all I can think of at the moment and I really need some sleep. Hope that helps.

 

[ledstein]

In easy terms the best power led is the one that "makes the most buck for lowest bang" ( most light at lowest mA). The is important because of the heat factor. More mA mean more heat which is hard or expensive to manage
Right now that Cree is at an advantage here. At 350mA their leds are brightest.

 

[JohnR66]

Why is the Osram Golden Dragon LED so often overlooked in these discussions?

After trying a light with one, it gives about the same output as an XR-E, nice mid 4K Kelven white and has High CRI. The optics look good for reflectors as well. I'm impressed!:twothumbs

 

[ledstein]

Why is the Osram Golden Dragon LED so often overlooked in these discussions?

After trying a light with one, it gives about the same output as an XR-E, nice mid 4K Kelven white and has High CRI. The optics look good for reflectors as well. I'm impressed!:twothumbs

What bin was the XR-E? What goldern dragon did you test?
Osram is behind in this filed. They only managed to come with the Ostar which has a huge price and makes tons of heat.

 

[R33E8]

What bin was the XR-E? What goldern dragon did you test?
Osram is behind in this filed. They only managed to come with the Ostar which has a huge price and makes tons of heat.

Well they all should make the same amount of heat at the same power.. If they make more heat at the same power then that should mean that there is a better thermal connection to the LED die..

 

[saabluster]

Why is the Osram Golden Dragon LED so often overlooked in these discussions?

After trying a light with one, it gives about the same output as an XR-E, nice mid 4K Kelven white and has High CRI. The optics look good for reflectors as well. I'm impressed!:twothumbs

I think you may be right that it is somewhat underrated. One problem is it doesn't do so well at higher current. I have one and it does indeed have a nice tint but I woudn't go so far as to say that it has high CRI. Not even close.

 

[JohnR66]

I think you may be right that it is somewhat underrated. One problem is it doesn't do so well at higher current. I have one and it does indeed have a nice tint but I woudn't go so far as to say that it has high CRI. Not even close.

Color rendering looks very good in the example I have. From memory the specs gave the CRI at 75 or 80. This is good for a white LED and is better than most CFL and many non incandescent light sources.

 

[saabluster]

Color rendering looks very good in the example I have. From memory the specs gave the CRI at 75 or 80. This is good for a white LED and is better than most CFL and many non incandescent light sources.

I'm sure it looks fine to you. This leads me though to believe you do not have any true high CRI LEDs such as the Nichia 083 or the SSC P4 high CRI. Am I correct? When you do a direct comparison what you thought looked great can suddenly look absolutely horrible. I speak from experience. ;)

 

[ledstein]

Well they all should make the same amount of heat at the same power.. If they make more heat at the same power then that should mean that there is a better thermal connection to the LED die..

Ostar is a multichip LED (6 chips) and at 350mA@20V makes tons of heat.