LED ratings?

I've been reading A LOT the past couple days and keep seeing a lot of different CRREE "model numbers".

P4
Q3
Q5
W2

That's in order from most powerful to least powerful right? The Q5 is much brighter than the P4 and the W2 is even brighter? And most of these are cree xr-e? does the e stand for economy?

thanks!

http://www.cree.com/products/pdf/xlamp7090xr-e_b&l.pdf
Cree categorizes its LEDs into different groups depending on high efficiently the die can output light. The more efficient the die, the further down it will be placed on the alphabetical and numerical order.

Simply put, a Cree die with R5 rating will be more efficient than a Q3 one.

That makes a lot of sense! P,Q,R....I bet theres S and T too (or will be) =p

thanks for the explanation. Now, will an R2 get hotter or drain battery more quickly than a P4? Or is that were the "high efficiency" comes in and it has the same battery usage and heat generation as an emitter that produces less light? Is it basically always better to choose a higher "tier" die?

thanks!

There is a separate sub-forum for discussion of LED types, bins etc. I'm moving your thread to that forum. You'll find the information you seek there.

llmercll said:

That makes a lot of sense! P,Q,R....I bet theres S and T too (or will be) =p

thanks for the explanation. Now, will an R2 get hotter or drain battery more quickly than a P4? Or is that were the "high efficiency" comes in and it has the same battery usage and heat generation as an emitter that produces less light? Is it basically always better to choose a higher "tier" die?

thanks!

Click to expand...

Generally speaking, you're correct. The higher the bin, the more light the LED can output for the same amount of current.

Also, there are already S and T bin emitters. The XP-G is up to S3, and the XM-L is at T6.

In your first post you mentioned W2. That's actually a tint code, and not related to efficiency. There's a lot of codes out there, and it's easy to get confused

Just don't fall into the trap that a lot of people here do. You'll see a lot of folks talk about a "Cree R2". That does not define what sort of emitter it is. Cree make the XR-E, XP-E and the XP-G in the R2 bin. Defining which emitter is important, especially if you're buying or selling a light.

Here are a couple of threads you may want to take a look at.

Commonly Used LED Emitter Index
http://www.candlepowerforums.com/vb/showthread.php?270419-Commonly-Used-LED-Emitter-Index

Bin Coding: Color, Flux and Vf Charts and Links for Popular White LEDs
http://www.candlepowerforums.com/vb...nd-Vf-Charts-and-Links-for-Popular-White-LEDs

Great, this is all very useful =)

What do you guys think about the MC-E? It looks wicked powerful I'm considering picking one up. According to the charts it's about 2x as bright as an R2!!!

llmercll said:

What do you guys think about the MC-E? It looks wicked powerful I'm considering picking one up. According to the charts it's about 2x as bright as an R2!!!

Click to expand...

The R2 LEDs (XR-E & XP-E) have a single die. The MC-E puts 4 of these dies inside a single case giving close to 4X the maximum light. The problem is there are gaps between the dies which gives a shadow in the shape of a cross in the beam. To avoid this the reflector is slightly defocussed or an OP reflector is used which produces a floodier beam. Wider but less intense hotspot.
A number of newer LEDs have been introduced - The XP-G and the XM-L (plus the SST-50 & SST-90) which are single larger die LEDs. These avoid the need to defocus the reflector but usually are still floodier than the XR-E/XP-E when used in a flashlight. The XM-L is probably better than the MC-E at 3V to 3.5V input. The MC-E can be wired series or series/parallel allowing higher voltage lower current operation.


An R2 can give you a much tighter and more intense hotspot as on the left. An MC-E will give you a floodier less intense hotspot but more overall light. (Actual picture is Q5 vs SSC-P7)
If you really need to reach far an R2. In Mid to short distances XM-L.