If you look under an electron microscope the air pockets between two metal surfaces are huge even if you lap them.
This is why thermal paste is the difference between working properly and instant overheating in computers. It has been tested literally hundreds of times in all kinds of applications, thermal paste is ALWAYS better than no thermal paste (unless you use bad thermal paste of course)
A few percent higher output basically means the LED is running much cooler, if you look at the lumen vs temp graphs. Why it was LESS output with thermal paste, I do not understand.
If the LED was not damaged, then the only explanation for the lower output with thermal paste is that you didn’t screw your MCPBC to the heatsink properly.
Also I don’t understand how you’re doing all of these tests without monitoring your temps with a thermometer…
Next time check the temperature delta between the LED and the heatsink with and without thermal paste and you will see for yourself.
What you’re basically doing is completely defeating the purpouse of an MCPCB.
That depends on your definition of a flashlight. Maybe you don’t consider my 1.5Mcd lightcannon a “flashlight”, that’s your opinion.
My opinion is that Your logical fallacy is ad hominem
And guess what? His tests with a LOWER bin get several HUNDRED lumens more than your tests. (for example the XP-L HI test)
I don’t care if that’s 5% or 1% but several hundred lumens is a lot.
Sorry that I completely disagree with your methodology, but people need to understand the big difference that thermal paste makes. Yes LEDs aren’t as expensive or important as computer components, but it does make a big difference (when applied correctly, screwed down with equal pressure, etc etc etc)