Dedomed?

[TeaSipper]

I've read that my new light (Acebeam K65) has a dedomed LED. What does that do?

 

[Strintguy]

I think it improves throw

 

[thermal guy]

Leds have a dome over them for protection and to create spill and beam shape. What they do is slice the dome off with a blade or I'm sure there's other ways and this increases throw considerably

 

[TeaSipper]

So the dome serves to spread the light thus creating spill?

 

[Bimmerboy]

Hopefully I have this somewhat correct as I haven't seen some of the old experts on this subject around for a while. Anyone, please feel free to correct me.

A LED with no dome will create more spill as it will spread all its light everywhere without any focus. More of the light will hit the sides of the reflector which allows it to be projected forward.

One of the effects of a dome is to present a larger image to the optics or reflector being used. When that happens (and here's where I could be going way off the rails), it is taking the luminous flux and spreading it out over a larger area, reducing apparent surface brightness. If I remember correctly, surface brightness is the key factor in "throw".

Again, if any optics people are reading this, please correct anything I may have gotten wrong.

 

[TeaSipper]

That makes it interesting. The dome is the lens right? So the dome being a convex in relation to the LED it would have spill. Without the lens the LED would be a focused beam thus making it a thrower.

I have that right?

 

[Bimmerboy]

I should've qualified my statement on that as in regard to the LED being in a reflector. Without a reflector, a de-domed LED makes more spill by itself than one with a dome, which does act as a convex lens. However, in the proper reflector, the "natural" spill from the de-domed will be projected forward. In a domed LED, less of the emitters' natural spill will hit the reflector wall.

Oh, man... I'm treading in dangerous waters here. Never actually "studied" basic optics... lol.

 

[Chauncey Gardener]

I should've qualified my statement on that as in regard to the LED being in a reflector. Without a reflector, a de-domed LED makes more spill by itself than one with a dome, which does act as a convex lens. However, in the proper reflector, the "natural" spill from the de-domed will be projected forward. In a domed LED, less of the emitters' natural spill will hit the reflector wall.

Oh, man... I'm treading in dangerous waters here. Never actually "studied" basic optics... lol.

Nevertheless, you are an excellent driver! :twothumbs Count me among those that are pleased to see you posting again. Welcome back from LIFE.

 

[TeaSipper]

I'm not well versed in optics so we're in the same boat.

 

[Bimmerboy]

Chance - LOL! I even have a little blue cone of autocross victory straight from BMW to prove it. If they only knew about the underwear thing... they let me race their brand new cars.

Of course that lowered their value... That definitely lowered their value. Gotta' go to Kmart.

It's good to start getting active again, and count me among those who are pleased to see you here, and having fun!

"Life". It ain't gonna' make enjoyment by itself! Some time has to be carved out for it, or it won't happen.