I have a later model SF L1 that supposedly has a TIR optic. It looks like a regular reflector in there to me? I remember the older E1L and E2L lights had a weird bubbly lens in the front, was that the TIR? Also what does the TIR do that a regular reflector doesn't (I have read tighter beam, but how?). I will gladly read a thread on this but I searched and couldn't find one. Thanks.
Guys who know more than me will be on soon, but I would reposond by saying that it sounds like you have the newest L1 Cree- assuming that your light isn't older than my luxeon L1 purchased years ago.
This new light has a TIR optic, but it doesn't have the crazy "bubble" appearance of the older models. The TIR focuses the light in a way that the reflector isn't able to with an led. The beam it creates is very tight, (at least in this case- i've heard that there are optics on the wide Malkoff drop ins- but again, this stuff is out of my league-) and on the newer cree model L1, also seems to give very usable sidespill. (Although many folks here, including me, like even more than it produces- but it is still a good trade-off, because the throw is amazing.
The new optic also did away with the square beam of the old model.
OK- I will let the guys who know a lot more than I do give you the details!