Oh, OK. So if you separate the actual LED from the rest of the package is it still a LED or just a trashed sliver of silicon carbide?
Nevermind dude. You're missing the point.
And between two XM-L emitters or two XM-L2 emitters of differing tints are there any visually distinguishable differences?
Looks that way if you look at the LED at extremely low output (moonlight mode on the sc52 xml2 for example).
I'll try to take a picture of it.
No problem, you’ll learn. 
Just keep in mind this can be a very technical hobby, like cars or guns, or like physics and chemistry, and terminology can sound similar for different components, so the correct terms are important.
When the LED are off you can see darker color when the tint goes to warmer tint (mistaken doxa,infact it is cooler).
Cool white are lemon yellow, warm white is orange because there is more phosphor on the die.
Wow, I’m learning in this thread…didn’t even know the SC52 came in a XM-L2 emitter, I thought only the brand new SC600II’s did. I guess it’d make sense for them to update their emitters across the board.
The SC52nw is xml2t6. The SC600II was xmlu3, as were the S6330 lights. The SC52 cw/regular, which came out a long while back, was also xmlu3.
All of the newer lights coming out from them now seem to be xml2, which makes sense.
Right now I'm anxiously awaiting my SC600II NW, with the xml2. Cellguy has the XMLu3 versions for sale pretty cheap. I know intellectually it's only a small bump, but I also enjoy warmer tints more.
This is obviously an extreme example, 3000K top, 6500K bottom
It's really hard to spot which is which when the tints don't have that wide a spread between them.
Huh, I didn't realize a difference would be visible. What about between ~4500k and ~5500k?
I tried a pic with XML2 4C, 3B, 3A, & 1C, cropped out everything but the dies, and I couldn't tell them apart. If anybody wants the full size version to play with in photoshop, right click/save as--> http://75.65.123.78/Dsc06275.jpg
A little late, but the green thing, the led is setting on is called a substrate. 
http://ledsmagazine.com/features/10/9/7/1309ledsweb_pack2
I really can't tell the difference in that photo either. Thanks for taking it though.
Silicone lens huh?
Well, I certainly learned something new today. Thanks for sharing.
Ahh righto, the green thing has a name, cheers!
Is it still called a substrate if it's silver instead of green? (this place really needs a :poke: ani-gif!)
(sorry, couldn't resist :party: )
I was wondering, what is that silver part on the XML2? I think the XML2 is built a little differently than the XML.
I'm pretty sure that the green part on the XML is a solder mask. Directly under that is the metal trace. And under that is the ceramic substrate.
Is the silver part on the XML2 just the metal trace layer?
I think you’re right rojos, the metal trace seems to be directly under the die on the XM-L2 version, whereas it’s buried on the XM-L.
Does anyone know of the most efficient way to slice the silicone dome off while leaving a very thin layer over the phospor? Would a very sharp blade like a scalpel be best? Heated? A heated wire? Heated as in glowing red? I’d like to shave the dome off an MT-G2, but I want a clean slice one time…don’t want to hack at it.
I have used a scalpel on a xml. It works but, its almost impossible to get a very nice flat cut. The doom can be shaved off like cutting a piece of plastic, very hard to make the cut perfectly flat though.
I can see a difference of the yellow under the dome between an XML2 T5 4000k in the 5Dish area and an XML2 U2 that comes in the XINTD x3. Don’t have my XML2 t6 3c to compare right now.