How to tell the difference between 2600 and 2900 lumen TK75?

Silver & two little gold bond wires is XM-L2, green & three bond wires is the older XM-L. There's no criss-cross pattern on either version.

with the dome removed:

Thanks for the photo’s, so XM-L2 are ONLY on silver bases?

And XML’s are ALWAYS on green? No exceptions?

They aren't 'on' green or silver anythings, that's the color of the material they're made of. A green XM-L2 would probably be about as common as a 4-door AC Cobra.

Hes talking about the GREEN sinkpad…

Meant sinkpads…no need for the condescending tone

Condescending what? You were asking questions common for somebody who doesn't know these things, I was trying to explain that the green part and the silver part is the LED itself, not some other component. They both have the same solder pads/footprint on the bottom, they can be soldered to any board made for that platform.

And where the hell do you see a green Sinkpad?! I see a post with two black aluminum MCPCBs, and another with a white 20mm Sinkpad and a white 16mm Sinkpad...

What’s the green thing the LED is sitting on then??

If the seller looks after you, all the more reason to sing their accolades.

The green thing IS the LED.

Does this help? (I really am trying to help, I'm answering questions, I even dug through the parts box for props to take this picture...)

Bare XM-L on left, underside on the right showing the + & - contacts, and big thermal pad in the center

XM-L and XM-L2 share the same dimensions on the contact pads on the bottom, they can be interchanged on any board that uses the 'XM-L' layout. There are other brand LEDs that use the same basic footprint and they can all be used on the same boards.

It certainly is a part of the LED. I think the actual name for what we normally call an "LED" is an LED package.

The actual Light Emitting Diode part of the package is the die, so technically, lionheart wouldn't be wrong in asking what is the green thing that the LED is sitting on, cuz that would be another way of asking what is the green thing the die is sitting on.

But generally, I think we refer to the entire package as the "LED" and not just the die.

I think we all know what I was saying…some people just enjoy being a bit nitpicky with the terminologies.

Sorry, I don’t mod and still very much a novice at all of this.

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.

Cree - flashlightwiki.com

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. :slight_smile: 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.