Rosebush was a dud. It didn’t even scratch the dome. Those thorns sure are sharp but I guess not sharp enough. Any other ideas?
I once stepped on a rusty nail. It went right through my shoe! Ouch! I just don’t know how that can be applied to this particular conundrum we are having. I feel I am close. Sharp does seem to equal cutting or stabbing from my empirical observations and my a posteriori experience.
The Cree XM-L spec sheet gives some useful critical dimensions: (± .13mm)
The die is .73mm tall, dome + die is 3.02mm.
Allow for some thickness of the solder bond, and leave some dome to save the bonding wires. (it’s not much here as mine is so close and somehow spared the bonding wires.)
Select a spacer washer thickness for the blade as guide. I think you can still get straight razor blades at most drug stores. This job can be done with a simple jig and work to surgical precision.
That is not evident at all from the page you cite, which only repeats what’s already been mentioned here. We know as basic fact that the dome has index>1 and concentrates the light. It’s not clear why a slightly wider beam collimates significantly despite same exit aperture. It was a guess that the shape of reflectors (simple parabolic?) is somehow more optimized (and by optimized I mean not bother to optimize at all) to a point source, and for whatever reason focus a flat emitter better than the beam out of the domed lens. It’s also entirely possible several factors combined, like reduced thickness of an optically imperfect material.
“It appears from the evidence that de-doming increases the amount of scattered light, and reduces the light ‘focused’ forward by the dome, thus increasing the amount of light focused by the reflector into the hot spot. Makes sense.”
The only “evidence” from your post is some guy did the sim in optics SW in that thread, so now I’m confused what other evidence you’re talking about.
It’s on topic. I am just attempting to find a suitable alternative method to de-dome a XM-L emitter for the masses. Not everyone has free access to high tech instruments like razors so I thought I would do the grunt work of theorizing a surrogate approach.
Agenthex, isn’t this pretty much exactly what you’ve been trying to tell me de-doming does? I just got done confirming this in my head with further reading and more posting from you guys.
I am likely to accept further “evidence” to be what I experience myself after I successfully de-dome an LED. It kinda appears to be what’s going on here.
That link only re-affirms what’s been said on the subject of color/tint. If you look at the prior wiki link, the question of how a simple change in geometry significantly increase collimation isn’t so simple without some knowledge of how these reflectors are actually designed (or ill-designed).
