Emitter choice for maximum throw?

[keltex78]

@scianiac

I’m a little disappointed more people haven’t tried the Oslon Black Flat more.

I’d be all over it if it was available via our normal channels… :nerd_face:

[scianiac]

It’s not that bad buying them from mouser or what have you, the real pain is the MPCBs and the hot center pad.

[djburkes]

@Wrathbringer27

@djburkes

A dedomed XP-G2 clearly throws further in a C8 than a XP-HI does. I’m almost tempted to say that a dedomed XM-L2 U41A throws further than an XP-L HI in a C8 as well…but I’m not too sure about that.

It think it doesn’t. I remember Robo mentioning something about a better beam for hunting after swapping out the XPL Hi in the BLF TE thread iirc. But the older XM-L2 has more lumens on higher amps as compared to the current ones. That’s one complaint I can confirm here.

I’ve built C8s with fets with XP-L HIs, dedomed XP-G2s, and dedeomed XM-L2 U41As. The dedomed XP-G2 out throws the XP-L HI for sure. By looks imo, a dedomed XM-L2 U41A out throws an XP-L HI too. I’d have to see some actual test numbers in the same version C8 to convince me otherwise. As I can only go by sight in my own experience. The BLF-TE and C8 are two totally different lights.

[EasyB]

To put some numbers on the throwing capabilities of the emitters: for a given reflector or lens, the luminance (cd/mm^2) of the emitter is what determines the throw. The old XP-G2 S4, dedomed, has about 190 cd/mm^2 driven at ~4A. The XPL HI or dedomed XML ranges from 115 to 140 cd/mm^2 at ~5-6A.

The S2 with smooth reflector is a good choice if you want a very small thrower. I made one with the old XPG2 dedomed and measured 40,000cd at around 4A. The stock OP reflector managed only 23,000cd under the same conditions.

[kiriba-ru]

Throw depends from optics.
All wroten upper is right for C8+reflector.
If you want to have maximum throw from small ligths like S2, it is better to use narrow tir optics.
But if you are using tir optics, better throw will have smaller die leds. Don`t look at wattage, just on led die size.
I suppose that best leds for throw under small tir is OSRAM leds made for car headlights.

[sb56637]

Sorry to the offended users who had to read the scum that was posted in this thread. It is now removed and the offending user has been permanently banned.

Now, back to the regular programmed discussion in this thread….

[posternerd]

@emarkd

I’m not about to get involved with the silly name calling in the comments above, and I know nothing about any production changes for these emitters so I have no comment there, except to say that if that’s true then obviously my observations may no longer be relevant, but I’ve built C8s with all three of those emitters myself just to see the results. In my lights, my dedomed XP-G2 was the furthest thrower by far. I got 795m out of mine. The XP-L HI on a fet driver missed it by almost 100m, but it does have a wider beam profile and is probably more useful in real life. The dedomed XP-E2 can’t be fet driven because it can’t take the power, but I drove it as hard as it would supposedly take, 2.3 amps. Little guy hits 670m, so quite the performer. Its an absolute pencil beam though, so not as impressive in real life as the meter reading would imply.

Thanks for your advice. This was exactly what I was looking for when I created this thread, but I’m not saying that other people weren’t helpful. I’ll have to do some reading about the changes to the production process of XP-G2s to see if they’re still suitable for throwers. CREE’s changes definetly make a decision tougher.
The super-throwy performance of the XP-E2 is interesting, especially at that amperage. It’s a shame it can’t take higher current though.

I don’t get why some people were so quick to anger. I joined BLF to avoid this type of hostility.

[emarkd]

@posternerd

@emarkd

I’m not about to get involved with the silly name calling in the comments above, and I know nothing about any production changes for these emitters so I have no comment there, except to say that if that’s true then obviously my observations may no longer be relevant, but I’ve built C8s with all three of those emitters myself just to see the results. In my lights, my dedomed XP-G2 was the furthest thrower by far. I got 795m out of mine. The XP-L HI on a fet driver missed it by almost 100m, but it does have a wider beam profile and is probably more useful in real life. The dedomed XP-E2 can’t be fet driven because it can’t take the power, but I drove it as hard as it would supposedly take, 2.3 amps. Little guy hits 670m, so quite the performer. Its an absolute pencil beam though, so not as impressive in real life as the meter reading would imply.

Thanks for your advice. This was exactly what I was looking for when I created this thread. I’ll have to do some reading about the changes to the production process of XP-G2s to see if they’re still suitable for throwers. CREE’s changes definetly make a decision tougher.
The super-throwy performance of the XP-E2 is interesting, especially at that amperage. It’s a shame it can’t take higher current though.

I don’t get why some people were so quick to anger. I joined BLF to avoid this type of hostility.

You’re welcome. I would like to say that that sort of behavior isn’t normal around here. I mean we’re all human so it’s not unheard of, but most folks here are very helpful and friendly. Plus our mod does a good job of keeping things cleaned up when needed as happened here. Don’t let this color your opinion of the site just yet.

[sb56637]

@posternerd

I don’t get why some people were so quick to anger. I joined BLF to avoid this type of hostility.

Yeah, it was basically instigated by one ex-user, and it was indeed completely uncalled for and inappropriate. My apologies for the unpleasant experience, and I hope it won’t happen again.

[posternerd]

No problem. I know these things can happen from time to time, even at places like BLF. Your good work is part of the reason I decided to stop lurking here in the first place.

[posternerd]

@Sirius9

@posternerd

I just remembered that the XP-G3 is now a thing. Is the die the same size as before?

XP-G3 is a bit different, not exactly suited for throw because it is hard to dedome it, I haven’t seen successful demode of XP-G3 yet.

Good to know. I’ll have to keep that in mind.

[Dimbo_The_Blinky]

@kiriba-ru

If you want to have maximum throw from small ligths like S2, it is better to use narrow tir optics.

That’s what I’m trying.

I found an 8° TIR at Fasttech, but the LED cavity is cut for an XR-E (IIRC) and it makes a nasty beam.

The next-best one they had is 15°, which I’m EDC-ing now. It’s lost next to the C8 I just built, with the same LED and Driver.

Is there a really really tight TIR, 20-21mm OD, cut for an XM-L2 (I don’t have an XP-G2)?

I don’t see the S series replacing the C8, but I would like to see how far it will reach.

[kiriba-ru]

@Dimbo The Blinky

@kiriba-ru

If you want to have maximum throw from small ligths like S2, it is better to use narrow tir optics.

That’s what I’m trying.

I found an 8° TIR at Fasttech, but the LED cavity is cut for an XR-E (IIRC) and it makes a nasty beam.

The next-best one they had is 15°, which I’m EDC-ing now. It’s lost next to the C8 I just built, with the same LED and Driver.

Is there a really really tight TIR, 20-21mm OD, cut for an XM-L2 (I don’t have an XP-G2)?

I don’t see the S series replacing the C8, but I would like to see how far it will reach.

You are on wrong way.
All chinise 8-15 degrees optics have more than 20 degrees in fact.
Convoy S series flashlights have about 17.3-17.4 head/bezel hole, workable part of tir should not be bigger (or you will loose lots of throw).
If you want to use xm-l2 in small light, reflector is your choise.

[luminarium_iaculator]

There is really no more throwier emitter than de domed old production type of XP-G2 S4 2B emitter (but other old production types of XP-G2 like XP-G2 S2 1A are also good choice )

You can use new production type of XP-G2’s but lux drop(de domed), is something you should prepare to.

Djozz review:

@djozz

Output results.

I tested the new XP-G2 S4 2B for voltage and output and plotted it against an earlier test of the XP-G2 S4 2B. I followed my usual method. Some remarks:

*these are tests of single leds, mind that results will vary among equally spec’ed leds within the voltage and output bin-classes

*since last XP-G2 S4 2B test my current measuring has changed a bit, the same current reads 0.1A lower now, this is not corrected in the graph

*since last test I cleaned the inside of my integrating sphere, it reads ~1% higher now, this is also not corrected in the graph.

What can be seen:

-If you correct the new numbers to 0.1A higher current and 1% lower output, the old and new led have virtually the same output up to 3A. Above 3A the old led seems to gradually perform better, so the new led seems to have a slightly worse thermal resistance. But it must be said that I did not reflow the leds myself (based on own experiments I use solder quite generously) , both were done by intl-outdoor: a thermal pad with somewhat sparse solder could already account for this difference.

-The voltage is a different story, once again in a new batch the voltage went up: by 0.1V at 1.5A, and 0.2V at 4A. This is of course killing for single li-ion use in flashlights, and this may be the single most important cause of the lower performance reported by LI. There is of course the uncertainty of measuring just one led, it could be a particularly high voltage one.

At 1.5A, which is the highest current that these leds are officially rated for, the performance of the new batch XP-G2 S4 2B is great, a somewhat higher voltage but I doubt that it falls out of specs with that :(

I’m not sure if I need to proceed with dedoming and further measurements, the results sofar explain IMO pretty well what is going on with this led…

RMM review

@RMM

Reposted here from my sales thread.

——————————

OK, here are the results:

“Old” XP-G2

3.87 vF @ 3.9A

“New” XP-G2

3.78v vF @ 3.9A

I tested two samples of each, and they are both within 0.1v of each other. I see that much variation or more from different emitters from the same piece of tape. I also only tested at 3.9A, so things may be much different at higher of lower amps.

I am not kidding when I say that this does not look green to me. It really doesn’t. The bare LED doesn’t, and I put a lens up to it and shined it on the wall and it doesn’t look green. I asked Lisa and a friend that is here today if they thought one looked different than the other (not knowing which one was the new or old) and they couldn’t really tell.

Here is a macro shot of the new and old (note that there is some perspective shift):

New

Old

Even despite the perspective shift (there is some) you can tell that the die size is slightly different.

So, for the small sample size (only 2 emitters from 2 batches):

• Green hulk dedome: BUSTED

• Higher vF: BUSTED

• Bigger die size: VERIFIED

What I strongly disagree with RMM is tint shift. Tint shift toward neutral with ugly green pigment happens if you don’t use lacquer like led seal RMM use or diamond lacquer that Vinz use.

Difference between un lacquered emitter and lacquered one is that lacquered will lead to cooler tint because as MEM explained this to me; “anything that can fill air gaps can help aid extraction of blue light that normally gets trapped near phosphor”

So you really can use the new production process XP-G2 but if you for example have old production types of XM-L’s or XP-L’s lying around they will have same performance with bigger dice(in aspheric) or larger hotspot in reflector than mentioned new production type xp-g2.

This change had very strong affect on me…

I am also searching for substitute emitter for old production XP-G2 S4 2B and now I am depending only on you guys, your reviews and testings.

[erik]

@kiriba-ru

…. All chinise 8-15 degrees optics have more than 20 degrees in fact.
Convoy S series flashlights have about 17.3-17.4 head/bezel hole, workable part of tir should not be bigger (or you will loose lots of throw). If you want to use xm-l2 in small light, reflector is your choise.

do you know where to buy the smallest angle tir for convoy S ?

[kiriba-ru]

@erik

@kiriba-ru

…. All chinise 8-15 degrees optics have more than 20 degrees in fact.
Convoy S series flashlights have about 17.3-17.4 head/bezel hole, workable part of tir should not be bigger (or you will loose lots of throw). If you want to use xm-l2 in small light, reflector is your choise.

do you know where to buy the smallest angle tir for convoy S ?

Seems no of them will fit it perfectly. Head/bezel hole is 17.5.
I have some Khatod PL136915, it has 17.9mm bezel step and should fit A6 and some other lights.

[giorgoskok]

This optic fits perfectly in my blf a6 :

http://kaidomain.com/Product/Details.S020966
https://www.fasttech.com/products/0/10002020/1187501-20mm-15-degree-optical-lensoptic-for-cree-xm-l-led

[Dimbo_The_Blinky]

Yep! That’s the one I’m carrying today in my “S5 Clone”. It’s an excellent (IMNERHO) compromise between the Flood I usually need and the Throw I have found an occasional use for.

I’m hoping to find a TIR that will make a well-collimated “pencil beam” from an XM-L2 in this S series body…

Another fact about TIR that seems to me to be worth repeating, they all tend to blend the weird “Cree Rainbow” into a more-attractive Whitish color. I wish I could find a tight-angle TIR for the C8!!

[kiriba-ru]

@Dimbo The Blinky

I wish I could find a tight-angle TIR for the C8!!

http://www.khatod.com/khatod/view_news.aspx?2013,10
Optics workable size is same - you can cut bigger one to C8 size, or use smaller one with some ring/tube around.

[EasyB]

I would be surprised if an optic beat the smooth reflector in an S2, for peak beam cd. I believe it would come close. When you look towards the front of the flashlight and the reflector is filled with the image of the yellow die, you can’t get much better than that. Anyone taken cd measurements with these throwy optics?