furcifernova, I agree the bulb assembly looks much like a pill. The threads do seem like NPT. Since the fitting is copper, it kind of makes sense that it would be NPT.

For me, all the lumen, lux, watts, etc. just seem to raise more questions than answers. All I can go by to try and specify what I am looking to achieve is relative information based on lights I have on hand. I have several headlamps. One is the Nitecore NU25 (a fantastic unit). It produces 360 lumen using a CREE XP-G2 S3. I would like much more out of this lantern. A few years back my wife got me an Atomic Flashlight (as seen on TV), which supposedly outputs 1200 lumen. This is more in line with what I'm looking to achieve. From what I have been able to find, a XM-L2 has a spec of 1198 (10 watts, 3 amps). Apparently the XM-L2 is more efficient than the original XML emitter.

So if the XM-L2 is the answer, where do I find it in either a pill or the parts that allow me to build the pill myself? Is that the direction my quest heads now? If so, any thoughts? Also, what is suggested for PCB sizing. I see they often come in 12, 14, 16, and 20 mm. 14 might be good for me, but then would I have an issue with heat? Do I need the cooling area a 20 would provide?

Thanks again,