A Perfect Dedome?

A simple job doesn’t sound any harder than de-doming to me. Of course I am not doing that either, but I can talk.

The word salad is strong in this one, yes I agree muchly.

Not as much as in my OL DIY contest build… :wink:

I would like to thank Tom E on this thread…

Although I become your member just recently I was lurking this thread as a guest before…

Yes I have 100% rate so far and sometimes I don’t care to clean silicone residues and it still works perfect… I am testing each on aspherical lenses.

I recently tried to put fujik carefully around XP-G2 led emitter to protect those tiny wires from eventual drop or shock… I got that idea thanks to DBCstm and his black solder glue(page eight) that looks very interesting so I ordered some of that from ebay…

It is still on a shock test but I think Fujik can not harm to those tiny wires as when it cures has similar properties as pencil eraser we used so much in old school days…

Any idea of protecting led after de-doming would be much appreciated…

LED Seal - LED Supply.com

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I did another XPG2 with cuts all over the dome, dome floated off after 40 minutes, left it in for another hour and every bit of silicone was gone. Didn't even need to use the plastic scraper.

How about dedoming bare emitter before soldering it to al/cu base?

Having it mounted to something makes things a lot easier, even if you have to move it to a different board after the surgery.

that’s true, it’s easier to manipulate when you have a star to hold it, with bare emitter there is much more chance that something will go wrong but last time I tried to do XP-G dedoming I noticed something like rust on one side of the emitter, the place where emitter touches the al board, strange, because aluminum oxidation is white and this was something like black rust…

I have throw beam pictures that I will upload when I find a place to put them.
I glued a –116 mm focal length concave lens to black construction paper and stuck it over the led of a Sipik 68. I think the curved surface sat right on top of the dome. I unscrewed the bezel almost till it fell off to get it to focus. The XR-E image was smaller, but maybe not any brighter.
So the first order optics concept is demonstrated, but it remains to be seen if one can actually get more throw this way. I have not found an easy way to figure light loss.

With secondary lens:

Without secondary lens:

Sipik Sk68 w & w/o diverging secondary on left. UltraFire SK68 3 Mode on right.

Well this seems ok for LED wire protection but I think we can expect great lux drop if we put that direct on phosphor layer of emitter because it creates thin layer of silicone or something like that…

Maybe this thing could work without lux drop but only on phosphor layer
Liquid Glass Shield http://youtu.be/xufAQ8SHLxc

I believe that somewhere out there must be simple solution(better than wavien collar) of improving phosphor brightness of LED emitter like some kind of super glow phosphor adhesive or spray that would double lux/lumen…

But if some guy finds out how to do it he will probably keep that secret for himself :slight_smile:

Hi guys. I de domed my first LED last night! (an XM-L) I used one of those safety type razor blades and wet everything with WD40 to reduce friction of the blade going through the dome. It worked well but, I initially planned to use some silicon shock oil from my RC truck as the lube since it’s clearer and more heat resistant but, couldn’t find it at the time. My initial cut was lop sided (LED was slightly inaccessable) so had to make numerous cuts to get it right-ish. The end result was not a flat surface but a very slight dome. The LED was a neutral white something and it didn’t go through any colour shift when ‘de-domed’. Honestly, it’s pretty cool but, the beam is so thin (LED is in a maglite with a Mag LED reflector) that it’s almost annoying lol.

Do you guys dedome for fun or for practical reasons?

For me it’s about warming a too cool tint and narrowing the beam for better throw.

I just did some work on my Solarforce M3 head, removed the star and took the XM-L U2 off of the aluminum, reflowed it to copper then de-domed it in gasoline with the cutting method. It worked well, the dome broke up and eventually everything was clean but it still took around 4 hours. I then removed the driver and replaced it with an E1320 5 mode, no blinkies. Was seeing 3.45A at the tail. Thought about it for a bit, bypassed the springs with a 20ga wire and added 2 chips for a total reading now of 4.22A. Very happy with that, with the beam (whiter and narrower with considerably more throw), and with the almost white tint (it was too blue for me before). :slight_smile:

This is why we do it! lol

For me, it's all about throw - doubling the kcd usually - that's why I de-dome. I think it's great for XM-L2's because a little more than doubles kcd, but with XP-G2's, I'm seeing a reduction in amps for some reason, so not getting quite double. In a mod'ed out HD2010 or SS T08, simply awesome of 200 kcd or so. Just did a C8 fully mod'ed with a XP-G2 and measured 142 kcd. Also I've done 3 TN31's so far and get about 349 kcd as I measured (resistor mod and XM-L2 U2 on stock copper), but most likely it's higher at 360-370 kcd when measured further out at 15 meters or so.

If you are thinking of a dedicated thrower, than de-doming is a must. Still want to do my Crelant 7G9, because it does about 120 kcd now, and with adding little more amps and de-doming, should get 260-300 kcd I'm thinking.

What is KCD?
Right after reflow, when she’s still HOT, you can take a dental pick and pull up the XM-L2 dome very easy. Then less soak time in the fuel.
I reflow the emitter, tin the pads, secure the sinkpad in the pill, and flip of the dome in one heating.

120kcd would be 120,000 candela, or the light of 120,000 candles.

Nice tip on the de-dome, didn’t think about doing it then…

Anyone dedome a Convoy M2 u2 1b?

candela is the standard unit of measure for throw - ANSI/NEMA FL-1 standards, see here: http://en.wikipedia.org/wiki/Candela and here: http://flashlightwiki.com/ANSI-NEMA_FL-1. I believe this is as of 2009 on forward. The spec costs $67...

Are you sure it applies to “throw”? Or intensity of illumination, regardless of angle?

“The candela (/kænˈdɛlə/ or /kænˈdiːlə/; symbol: cd) is the SI base unit of luminous intensity; that is, power emitted by a light source in a particular direction, weighted by the luminosity function (a standardized model of the sensitivity of the human eye to different wavelengths, also known as the luminous efficiency function[4][5]). A common candle emits light with a luminous intensity of roughly one candela. If emission in some directions is blocked by an opaque barrier, the emission would still be approximately one candela in the directions that are not obscured.

The word candela means candle in Latin, as well as in many modern languages.”

Wikipedia makes reference to blocking the light in some directions and letting it go in others, but does not implicitly refer to the direction as part of the meaning of the word, only that if the light is directed it is still the same power as if it’s left to radiate randomly.

Am I misunderstanding this? It does say that the light of one candle is referred to as one candela. I really never thought of a candle as having throw. Must be missing something. Again.

Honestly not trying to argue, would simply like to understand. It all gets confusing from candela to lumens. Difficult to understand where the “standard” is, if there is one. This means a lot to me as a photographer, trying to understand the concepts as they apply to taking a beamshot. I can make a Solitaire look like a TN-31 with my camera, but that doesn’t mean it’s so. My point is that I really need to understand the base concept so my beamshots will be reliable. Guess I need to send someone with a light meter out to a designated distance to take a reading on the amount of light hitting the meter at that distance, or more specifically have that person take the meter out until it registers 1 Lux, then get a reading on the distance. And here we go again, candela, lux, lumen, I’m lost.

Lumens = total light output
candela/lux = amount of light hitting something at a certain distance, also known as intensity.

I think I know where you’re misunderstanding. Are you saying that just because it reads a certain candela reading at 1 meter, it shouldn’t be the same at 10 meters because the beam will diverge?

Well, if that’s where you’re confused this is why for some super long throwers or even multi emitter lights we test it at longer distances to make sure that the beam is already fully converged and is starting to diverge. Eg. I can test my TN31 at 1 meter and get say 150kcd. But this is because at one meter there’s a noticeable ‘black spot’ in the center oft he hotspot because the beam hasn’t fully converged yet. Therefore, I should test it at a distance which is further than the distance it is at when it converges. This is why I (and many others) will test at 10 meters, and for my TN31 at 10 meters I get 3700 candela. Then I calculate it back to 1 meter, and using the inverse sqaure law I take the distance and square it, then multiply it by the reading giving me a total of 370kcd @ 1 meter.

Now with candles, you can measure it at 1, 10 or 100 meters it doesn’t matter. It doesn’t have a reflector and the light doesn’t have a hot spot, meaning the light is always diverging. This is why lights with reflectors need to be measured at a point which is after the beam diverges.

I’ll give another example. I can measure the throw of my Skyray King (3 emitters) at 0.5 meters and again at 5 meters (nobody actually measures this close, but it backs up the explanation). At 0.5 meters, the beam is probably at it’s convergence point or close to it, so if I calculated back to 1 meter, I get (I just measured this) 59kcd. However if I measure it at a longer distance, at 5 meters which is after the convergence point and I calculate it back to 1 meter I instead get 22kcd.

Not sure if I made it any clearer, but are you still confused?

EDIT:

Tom, is your 7G9 getting 120kcd stock? If so, something may be wrong with it, because it’s only supposed to get around 55kcd stock.

Well, NEMA, ANSI, along with all major manufacturers use lumens and candela and distance. Distance is directly calculated from candela - I certainly didn't make this stuff up, and certainly don't understand it all, far less than you I'm suspecting... If the industry adopted these as the standards, I think we should be using them. It's an industry adopted standard -- they are the only current standards - I see no reason to question them or come up with alternatives. People that know a lot more than me about light, and the technology behind it, came up with these standards.

It's the only way to compare -- this is why standards are adopted, that's what's it's all about, and it certainly comes in handy for us to compare stock lights, as well as seeing how effective mods are, if part of the goal of the mod is brightness and/or intensity.

I'm not paying the $67 to get the published standard, but based on the outline they made public, light output (lumens) and peak beam intensity (candela) are the two major measurements. I'm not saying my measurements are 100% right either, I'm just trying to do the best I can with what I got, and my methods and equipment seem to match up fairly well with what the FL-1 compliant manufacturers quote for their stock lights, and I know it's not perfect, and I know people have and always will question these methods.

The spec is all about flashlights, entitled "Flashlight Basic Performance Standard". I think this explains it: http://flashlightwiki.com/Light_Output_Measurements and here: http://flashlightwiki.com/ANSI-NEMA_FL-1.