[REVIEW] Acebeam W10. 1KM of throw, in your front pocket. 21700/18650, USB-C charging.

There are many factors that affect throw and optics quality is among them. A shallow reflector (like GT) has a smaller working area than a lens. A deep one has larger. Quality also matters, a lot.

With collar. Which is really a game changer.

Yes, you lose some area by having more emitter openings as well as some around the edges. In case of a siamesed 7-up it’s like what - 10% loss? Let’s make it 20% to have a good margin. You make up for it with 10% larger diameter. But your reflector is 6.3 times shorter. This won’t make your head 6 times shorter but 20%? Way more than that.

XHP35 HI at 2200 lumens does ~130 cd/mm². XP-L HI at 1200 lm does ~100 cd/mm².
I don’t really advocate quads as a quad is less efficient (when it comes to head use) than a 7-up.
And as I said, if you define size as diameter - single emitter wins. If you define it as volume - these 2 lights aren’t really comparable.

As long as you reduce die size proportionally to the number of emitters - no, at the given luminance you use the same power. But as I said it works better in theory than it does in practice.

Everything else you said is right, but if you simply add more emitters without changing the area of the optic all you’re doing is creating more lumens, not more throw.
The intensity would not change, the light output increases and you would get a larger spot (or multiple spots in this case, since the LES is so small)

Actually, since I said about making emitters smaller, I don’t gain lumens either. I just reduce head volume at the cost of having flowery beam and higher price. In some cases reducing cooling and worsening ergonomics as well, though in others either may be improved.

If we move out of the theoretical case of using 7-times smaller emitter then yes, multi-emitter thrower uses more power and gives more lumens without improving lux.

The whole discussion started with complaints that W10 does only 200 lm. I chimed in because I share that concern, I like certain cd/lm range and W10 is way out of it. A 7-up reflector would put at the very least 1500 in the beam and likely 2000+. It couldn’t be W10 sized though due to heat….

Oh you mean increasing the number of emitter but with their own optic each, then yeah that would increase intensity.
The reason the intensity increases is because of the more area, not more emitters.

If they used a more powerful but less concentrated laser they could achieve similar intensity but a larger spot and more lumens.
If they used a crystal they could get more lumens without increasing spot size, so both more lumens and more intensity.
But then it wouldn’t be a $200 flashlight it would be $1000.

It seems I fail badly at speaking clearly today. This is not the only discussion where it shows…
I was debating 2 cases:

  • theoretical advantage of multi-emitter throwers (the sole advantage being smaller head volume for the given throw)
  • getting more lumens out of LEP lights to make the beam wider

On the first topic I meant only diameter increase that would keep reflector area constant.
On the second one I meant to keep head size constant by having more emitters and smaller per-emitter optics. The purpose would be to have the advantage of superb throw that LEP offers while widening the beam (so I can see the target without binoculars). Though I mentioned a larger head because of thermals - this would again narrow the beam down. So keeping the as-much-throw-as-size-allows that LEP offers together with beam that’s wide enough for me doesn’t seem possible with W10 tech. I suppose that to widen the beam one would have to either reduce thermal issues by underdriving the LEP or by purposefully defocusing the optics. At that point indeed LEDs look more attractive.

But you mentioned another topic that I haven’t seen before - “crystal”. Quick search - you mean single-crystal phosphors, right? I wonder what’s the source of your price quote, I see some company claiming them to be as cost-effective as mixed phosphors.
Do you know of anyone who tried transplanting such phosphor on a LED emitter? Seems like something that saabluster would do.

See here (in German). There’s a lot of additional information regarding laser phosphor systems in general in the first post of that thread.

I don’t think I understand what you’re saying then, because no matter how many emitters you use the throw does not change if you keep a constant head diameter.

And yes I was talking about phosphor crystals.
The crystals are several hundred dollars, then a more powerful laser will also be several hundred dollars.
AFAIK there are only two companies that provide commercial phosphor crystals.

Thank you The_Driver!

Volume, not diameter. Multi-emitter reflectors are much shallower than single emitter ones of the same diameter.

Could you please name that companies?

Multi-emitter reflectors also have a lot of wasted area, which is why they are usually bad at throw.
One of the companies is cryphosphor, the other I cant remember but was way more expensive, you can find it by reading the research papers on single crystal phosphors, the universities state where they got their samples from.

Siamesed 7-ups don’t have that much wasted area. You can make up for the area loss by increasing diameter.
After you do so you end up with exactly the same throw, a bit larger diameter, but smaller overall volume.

Cryphosphor is the company I found, they claim that cost is comparable to phosphor powders. Hmmmm….

Please give us an example of a very throwy multi emitter light.

Tough call. Manufacturers don’t really attempt making such lights. Which doesn’t make the concept wrong.
I believe Emisar D4Vn with Oslon Black Flat is the throwiest light for the size despite using poor optics.

I don’t think that light exists . Please give me a light with a throw figure so I can compare it to other real lights.

It seems to have been removed.
It did exist:
I don’t remember throw though and I can’t find it, even web archive doesn’t help (because it doesn’t have D4vn page in the cache at all).
Dedomed XP-G2 does 40 kcd
It is still challenging to find something to beat 40K at that size though.

Am at work at the moment so I have no exact dimensions, built 2.5 years ago, the head size is about the D4, it does 58kcd. That is on a 14500 that does not drive the XP-G2 to the max.

Tough to find something that beats it at that size because it’s nearly the smallest single 18650 light out there. Even the Nitecore P12GT does 28 kcd, and that’s an off the shelf light with a 1” body. On top of that, the output curve looks like this:

Instead of this:

Not to mention that all the measurements of the D4 that are floating around are measurements at turn on instead of the industry standard of at 30 seconds. It’s a ridiculous, impractical measurement and the same sort of thing we’ve bashed the big camping brands about for years.

So yes, you’re right in that the D4 is the smallest light out there and nothing its size is throwier. But no, multi emitter lights are not throwier by nature, and once you get into looking for a light with x meters of throw, the smallest example will almost always be a single emitter light, and those will draw much less power and run for much longer. As for your comment about manufacturers not ‘making such lights’, that’s because they’re subject to the laws of physics. In multi-reflector setups, the space between those reflectors is lost. If what you’re suggesting was possible, it would have been done - the W10 is proof that manufacturers are willing to try new things to get big throw numbers.

Edit: Scaled the graphs so the time scales match more closely.

Definitely beats XP-G2 D4vn, thanks for showing that.

A part of what makes it so small is the fact that it uses a multi-led optics, isn’t it?

I showed some calculations here.
Do you see some error in them? I yes, please correct me.
ADDED: Actually I see an error in them. :person_facepalming:
Instead of 6.3 times smaller height that should be about 3 times smaller height, depending on amount of siamesing. This correction doesn’t change the conclusion though.

“A part of what makes it so small is the fact that it uses a multi-led optics, isn’t it?”

No. A single led catadioptric could have been smaller. Hell, you could simply make a mule.

Multi-led optics are shorter because their height is related to diameter of the lenses.

Please accept and understand that there is no way in hell a multi-led setup beats a single led at throw on an equal fight.

Multiple people here are trying to explain this fairly simple concept to you.

We’re talking about good throw to size (with size defined as volume, not diameter). djozz has shown that D4vn with XP-G2 is not a leader here, but I still maintain that it is quite good.

If Emisar made it a mule it would be smaller, but clearly would be bested by many non-18650 lights.
With catadioptric? If there was a suitable one on the market, it would be marginally shorter. Scaling down 10158 to 24 mm gives me 5.3 mm thickness, .7 less than what Emisar uses. Though I’m not sure how should I scale the rim below the lens, so that may be somewhat incorrect. Anyway - it would be smaller but probably slightly less throwy because of catadioptic’s low efficiency. It would definitely be less efficient. If efficiency is not meaningful then yes, catadioptric may be an OK option.

I would like to understand. But so far I understand it exactly the opposite way. And none of these people has shown a hole in my justification.

So far the argument on my side was a simple calculation.

Arguments on the other side were:

  • at same diameter, single emitter wins (I agree, but that doesn’t go against my argument)
  • multi-optics don’t use whole frontal area (I agree, I took it into account in my calculation)
  • nobody does it (I agree, but it doesn’t go against my argument either. Though certainly gives some food for thought)
  • other optics choices may be even better in this regard (I agree, though those other options come with their set of drawbacks)

Did I miss something?

I see some possible explanations on why nobody does it in practice. The biggest being:

  • the smallest Cree HI LED is 3.6x mm², 7 of them won’t make a thrower except for extremely large lights. You need very small high-intensity emitters for multi-LED thrower to work well. Like upcoming Osram KW CSLNM1.TG. Or like a LEP.
  • cost of a 7-up is much higher

There may be others, even bigger.


“multi-optics don’t use whole frontal area”

If you add more emitters, and maintain lumen output the same, you can’t have more throw, because you are wasting part of your optic space.

If you add more emitters, and drive them all hard, you may end up with the same or more throw, at the cost of a lot of other issues, like more heat, decreased runtime, lower efficiency, etc etc etc.

Man. This is a forum for flashlight enthusiasts. Some of the people answering in this thread have forgotten more about flashlights than I have ever learned. If there was a reasonable way to get higher throw by using multiple emitters, they would know. Flashlight companies and enthusiast have spent a lot of time and money making the best throwers possible, for profit or fun, and they all share one common factor: Single output sourcer.

The very user who made the lens/reflector calculator that you quoted already answered and told you that adding more leds won’t increase throw. What else do you want? A 60 page report?

Go ahead, build a light and prove me wrong. God knows I would love to find a way to cram more candela into a smaller flashlight. I’d be happy to be proven wrong.

EDIT: Simple example:

Smaller emitters are better for throw precisely because they are small.
What is the point of having a small emitter if you then add many emitters?

We want the smaller possible emitter because that usually results in a higher cd/mm. If you add more emitters… you won’t get as high a lm/mm. You are holding onto edge cases and theoretical math, when practice, real life, and available products tell the opposite story.