I have to admit, I have only dedomed one light as of yet, and Im still not sure if I'm a dedome kind of guy. Mostly, it's the tint shift that bothers me...but I regress, what I want to know, is there any real gain in a dedome in a small reflector.
Ive been thinking of mixing some dedomes in a multi emitter light (9-12 x XML) and was wondering if there is any real gain, or if it is merely imagined. As they add more emitters to reflectors, they keep getting smaller and shallower Until they are the size of AA and AAA lights.
So my question is: Is there any true gain in throw? I know there is in large reflectored lights, but in these small shallow reflectors, does it really make a measurable difference, or is it just some nominal gain like ten feet?
I believe it will still double the kcd in general, just like big reflectors. Dale has done small de-domes, as well as others I'm sure, so they would know more. Doing the math, 5 kcd to 10 kcd, is 141 meters to 200 meters -- not a bad bump.
Ex: Convert 10 kcd to meters (to moonlight which is 1/4 lux): SQRT (10000 / 0.25) = 200
I know the math supports those figures in general, but does it take into account the variables such as diameter and depth of reflectors. Is there a point that the reflector just doesn’t support the math and merely floods regardless of dedome.
I haven't done any small light de-domes, but I'm still thinking in theory, the effect you get from taking off the silicone should be the same, regardless of the reflector diameter. Hopefully someone will chime in who has actually done it and measured it.
I agree with Tom that in theory, the increase in bigger reflectors should be relative to the increase in smaller reflectors.
By doubling the throw (candela), you effectively increase the distance by 50%. If that’s worth the tint shift to you then why not?
Instead of being able to see 50 meters, just dedome it and you’ll be able to see 75 meters. Up to you whether or not it’s worth the tint shift (which I think is the only downside apart from increase vf especially in XPG2s).
I don’t remember if I saw this here, or on cpf, but someone did a before and after dedome shot on their MBI HF, and the increase in throw was dramatic.
Dedoming does the same things in a small reflector as in a big reflector. Would it really make sense to say, "well it's not worth it to dedome this 20mm reflector S2 because it will only increase throw by 45%, I'll do it to a C8 instead since that one increases by 50%"?
Agree, it works as well in small lights, it is a matter of taste: I don't like to carry around big head lights and do like a bit of throw, so quite a few of my small lights have a dedomed led. (My current EDC is a tube shaped very small 16340 light with a dedomed Nichia219B (92cri) )
The tint went towards 4000K, about perfect for me. My general experience is that high cri leds keep a very nice tint after dedoming, probably still high cri although I can not measure that.
I dedomed it by popping the dome off while still hot directly after the reflow (a thin layer of silicone remained on top of the die), so I would not know how gasoline works on Nichia's. I did try gasoline on a LuxeonQ and that ruined the led (a silicone mess with the phosfor coming off), my guess is that succes with the gasoline method is an exclusive Cree thing.
I dont know if this is what your after but at the end of the OP is a couple of shots of a dedomed XPG-2 and a 20mm TIR with a C12 for comparison. Theres more pictures somewhere from another member, if you want I could find them.