# Lack of high-powered super throwers



## Bright Bird (Aug 31, 2017)

The furthest throwing stock light that I know of is the Thrunite TN42, which will throw a tight beam for nearly a mile, despite only having an overall output of 2,000 lumens. Since there are lights with several times that output, shouldn't it be theoretically possible to achieve twice that distance with 8,000 lumens?

Obviously, a light with that output would need several emitters - so is the larger area that the light is emitted from the limiting factor? 

I'm hoping that someone can explain the physics behind how throw is achieved. Cheers! 

P.S Not sure if this is posted in the right forum - if not, can a mod please move?


----------



## archimedes (Aug 31, 2017)

Bright Bird said:


> ....
> P.S Not sure if this is posted in the right forum - if not, can a mod please move?



Done ... _moved to "Spotlights" forum_


----------



## marinemaster (Aug 31, 2017)

I can somewhat see in daytime at 400 meters, what do you need to see at nighttime at 1600 meters ?


----------



## Bright Bird (Aug 31, 2017)

marinemaster said:


> I can somewhat see in daytime at 400 meters, what do you need to see at nighttime at 1600 meters ?



Not me personally, but I'm sure that there would be a use for high-powered searchlights. Also, with a torch that reaches e.g. 2km, the light at that distance wouldn't be very bright. But a target at 500m could be lit up much brighter than by a light that only has a maximum throw of 700 or 800m.


----------



## STO (Aug 31, 2017)

There are lots of factors at work here, for one, twice the distance requires 4 times the candela so 4 times the performance. And for more lumens you either need more powerful LEDs which you get less throw performance out of or lots more of them in a massive flashlight since you need to maintain the same frontal area (assuming the same optical systems to keep this example simple) or more frontal area to get your increase throw. And I do agree with you the ANSI spec of 0.25 lux for determining distance is not very bright so often serious throw is useful at shorter ranges to have useful amounts of light. And there are lights that throw way farther than the TN42, excuse the moment of self promotion but in fact I make the longest throwing LED flashlight which already exceeds 3km, the trick of high lumens and high throw is what I'm working on next though and actually something along those lines will be released shortly.


----------



## richbuff (Sep 1, 2017)

Also, plus the informative replies above,

Throw and Power are very very inversely proportional to each other. It is very very difficult to get throw from a power configuration, and it is very very difficult to get power from a throw configuration.

As soon as you design a configuration for either throw or power, you give up ability to have more than some of the other aspect. 

Lack of throw in power flooders, and lack of power in throwers are because of the laws of physics, as explained in posts above. 

Getting some of both aspects, power and throw combined, requires a much larger head diameter. In HID, I am still searching. In LED, the X65 does what no other item can do. 

More = Larger head diameter. 

Smaller head diameter = Less.


----------



## Bright Bird (Sep 2, 2017)

Thanks for the replies. 3km throw?  Wow, that's something I hadn't heard of before ... I had a look at your site, STO, and those Ra lights look seriously impressive (especially when reading numbers like 2.6 megacandelas!).

Shouldn't it be possible though to focus a beam without using a large reflector - similar to how a laser beam is focused? I remember reading that throw in smaller headed lights can also be achieved by having a very long reflector, but admittedly I don't understand entirely how the photons and bundled and prevented from spilling beyond a certain angle.


----------



## ven (Sep 2, 2017)

If you want a high output light with plenty of throw with LED's...........10,000+ lumens and 600+ kcd, then check out the x65vn, recommend the 5000k xhp35 HI's.........real nice(subjective of course). Plenty of bright spill for S&R type uses, some of course prefer pencil beams.............again subjective and for the end user to determine for their application. 
http://www.candlepowerforums.com/vb/showthread.php?426136-X65vn-Best-Thrower-Searchlight


----------



## Bright Bird (Sep 2, 2017)

ven said:


> If you want a high output light with plenty of throw with LED's...........10,000+ lumens and 600+ kcd, then check out the x65vn, recommend the 5000k xhp35 HI's.........real nice(subjective of course). Plenty of bright spill for S&R type uses, some of course prefer pencil beams.............again subjective and for the end user to determine for their application.
> http://www.candlepowerforums.com/vb/showthread.php?426136-X65vn-Best-Thrower-Searchlight



Those Vinh lights are probably the Holy Grail for a lot of flashaholics (and not even as expensive as I had expected after previously watching some YouTube videos). But I am mainly interested in the physics of how the photons behave after they leave the emitter, and how different properties of the reflector influence that behaviour. When I googled 'reflector design', most of the results seems to be from manufacturers promoting their products, or websites describing the use of lighting in 3D modelling applications.


----------



## ven (Sep 3, 2017)

Have a search under certain specific in the top right google search. Here is one(not sure if it helps you or not). Saabluster(Michael) is a genius ...............
http://www.candlepowerforums.com/vb...Real-Reason-for-Throw-an-in-depth-examination


----------



## Bright Bird (Sep 3, 2017)

ven said:


> Have a search under certain specific in the top right google search. Here is one(not sure if it helps you or not). Saabluster(Michael) is a genius ...............
> http://www.candlepowerforums.com/vb...Real-Reason-for-Throw-an-in-depth-examination



Yay, exactly what I was looking for - thanks for the link, it looks like that's going to keep me busy for a while! :thumbsup:


----------



## ssanasisredna (Sep 24, 2017)

ven said:


> Have a search under certain specific in the top right google search. Here is one(not sure if it helps you or not). Saabluster(Michael) is a genius ...............
> http://www.candlepowerforums.com/vb...Real-Reason-for-Throw-an-in-depth-examination




Unfortunately that thread starts with a simple and incorrect definition of surface brightness. It is not simply lumens/area of the emitter. Equally crucial is the angle of emission of the source. Most LEDs are somewhat lambertian in their emissions so it makes a relatively good simplification for comparison, however, one area of research is to make LED emissions more directional which would increase surface brightness without increasing lumens or area. This allows for better optical control, i.e. for making better high beams for cars and/or reducing optic size.


As a sidebar, the analogy about the two stars in that thread: Stars are so small (angular size), that both would appear as a point source and there would be no difference in apparent brightness viewed with the naked eye from earth. It would take a very high powered telescope to resolve any difference. Betelgeuse, a red-giant, has an angular size almost the same as the angular resolution of the Hubble telescope.


----------



## The_Driver (Sep 26, 2017)

Here is a nice explanation. It's in German, so use Google Translate. 

For throw only two things matter: 
1. luminance of the light source (cd/mm^2)
2. Size (diameter) of the reflector or optic as seen from the hotspot (mm^2)

1. The luminance of a light source is what some people refer to as "surface brightness". It is the only unit of light that the human eye can directly perceive (how bright a light source looks when you look directly at it). Most LED manufacturers unfortunately don't list this in their datasheets (only Osram for some LEDs). It can be measured though, but a lot of careful work is needed. Luckily for us sma and Köf3 have measured some emitters and have compiled lists here and here (also in German).

Generally LEDs don't have a very high luminance compared to the best (short-arc) HID bulbs. Thats why no one has beaten the Maxabeam yet with an LED light of the same size. The LED with highest luminance (Osram Oslon SYNIOS DMLN31.SG white) currently goes up to ~300cd/mm^2. This is much higher than most other LEDs, but comes with a lot of trade-offs (very small Die, very low lumens etc.). The next best one which seems much more reasonable for flashlights because it produces much more lumens is the Osram Black Flat Gen2. It goes up to around 250cd/mm^2 and 900 Lumens. 

So luminance is candela per square millimeter of the size of the light source. To measure this you need to measure the luminous intensity of the light source (candela, [email protected]) without any optic or reflector from head on and also precisely measure the size of the light source. You also need to be very careful to not let any stray light of the light source hit the sensor of your lux meter. Only direct light should hit it. After you have done this you just divide the luminous intensity by the size to get the luminance. 
One thing to note: the luminance of a light source is constant. It doesn't change with the angle you look it at and optics don't increase it. 

2. The other thing that matters is the size of your optic or reflector. Imagine that you are standing where the hotspot of the flashlight is. What do you see when you look into the light? You see a glowing circle. You need to determine the size of this circle. So for reflectors you just need the diameter of both openings and for lenses you just need the diameter. Area = radius^2 * pi. This is the reason why the depth of a reflector doesn't really matter for throw. It has almost no effect. Only the outer diameter really matters.

So how do you get throw with these two values?
You just multiply them.
Luminous_intensity [cd or "[email protected]"] = luminance[cd/mm^2] x area_of_optic_or_reflector[mm^2]
Of course to be more precise you need to account for optical losses. A glass lens only transmits 92% of the light, a coated one 96-99%. A standard aluminium reflector will only reflect 90% of the light etc. But in general this is how you get throw. You can calculate it without actually measuring the flashlight (as long as you know all the details).

Since LEDs are basically lambertion emitters there is an approximating formula you can use to calculate the luminance based on the lumens and the size of the LED:
Luminance_of_LED = luminus_flux[lm] / (size_of_LED [mm^2] x pi)
This gets you a ballpark figure.

There are also some special things to consider:

Many LEDs have silicon domes on them to increase lumens extraction (because the round silicone dome has a more suitable refraction index compared to bare phosphor). These domes unfotunately halve the luminance! This is why "de-doming" an LED increaes throw. Stray photons are reflected back into the phospor and re-exite it (photon recycling). A better, more in depth explanation can be found here.
The Wavien collar is a way to increase the luminance of a LED by reflecting 75% of the light back onto the Die allowing it to be "recycled" and emitted in a different angle. sma studied the collars here. A maximum of 120% gain was observed, so with the best current LED 660cd/mm^2 would be possible. TSome downsides are that it can only be used with aspheric lenses (so no spill), the hotspot will always be very small and that they aren't available anymore without buying a 120$ flashlight.

Other light sources:
The light sources with the highest luminance are Xenon and mercury short-arc HID bulbs. They concentrate extreme amounts of power into a very small arc. They operate on the physical limits of what materials science has to offer (especially regarding maximum temperatures of the Wolfram elctrodes and the quarz glass envelopes). The highest achievable luminance is around 6000cd/mm^2 which is 20-times as much as the best LED. They also produce more lumens compared to LEDs with high luminance values. 

So, to answer your question, you will only get more throw with 8000 Lumens compared to 2000 in your TN-42 if the brighter LED is of similar size. If it gets larger than the luminance stays the same or even goes down and thus you might actually get less throw.

Here I have built a flashlight with the precision reflector of a Maxabeam and the Osram Black Flat LED at maximum power. It's very extreme for an LED flashlight, but still falls well short of the the real Maxabeam with it's Xenon short-arc bulb. 

Here Enderman built a light with Osram Black Flat, a Wavien collar and a large aspheric lens. He got 4.6Mcd which only some guys with much larger fresnel lenses have beaten. It shows what can be done if all you want is a farthest throwing LED flashlight.

Here I have compiled a list of the farthest throwing portable lights regardless of the used light sources. Lets just say - LEDs are still pretty dim compared to short-arcs!


----------



## ssanasisredna (Sep 28, 2017)

Very nice post.

If I remember correctly, the BMW laser headlights which are 3 blue lasers fiber-optically coupled to a single white phosphor point achieved a surface brightness on the order of 2,000 CD/mm^2. Stokes losses and optical losses in the phosphor limit efficiency so keeping the phosphor cool becomes an issue.

For LED, from a practical standpoint, depth of the reflector is important if the LED is at the back of the reflector due to the lambertian forward emission pattern. If you don't have a deep reflector, you won't collect any light and while that may not improve "throw" from a raw number standpoint, it is needed to have any size to the hotspot. However, if you point the LED back into the reflector then this practical limitation goes away.


----------



## Bazar (Oct 4, 2017)

marinemaster said:


> I can somewhat see in daytime at 400 meters, what do you need to see at nighttime at 1600 meters ?



Well that is ansi. And a 400 meter flashlight only throws useable light 200m. Then from there more intensity might be needed, like in the rain when 80% of light bounces off the ground, in which case producing light with 4 times the intensity will do what a 400m light does in the dry.
Which is not 4 times the distance to clarify, more like roughly 900 meters.

Further out the less meters you get per intensity matters.
For example to go from 15,000 candela to 30,000 you get per say 180 meters to 280 meters, but from 1000meters to 1100 meters you need much more than a 15,000 candela increase.


Lumens make throw worse for leds because they decrease the surface intensity. Or rather, typically higher lumens means less throw, even, with the exact same reflector.
So lumens doesn't equal throw, candela does. And higher surface intensity is more easy to throw with a parabolic reflector since parabalas need to use a small object to reflect.


----------



## Bazar (Oct 4, 2017)

Further as for the original question the answer is the target market. Things like the maxabeam(12,000,000 candela, literally, real not fake) actually use an expensive amount of raw materials, legitimate silver and solid blocks carved out for the reflector, as well as (get this) optical lenses that refocus the parabola of the reflector to an even tighter beam, are the best handheld throwers in earth, and though large, if you really want throw, you want alone of these, which will for added bonus, typically be able to be defocused into a floody beam with 6,000 lumens or more which is compared to LED lights absolutely overpowering, even the huge 17 LED 47s light can hardly keep up with despite being much larger. LED is great for efficient flood, but only a very wide big light, like the huge 47s light, is able to put any throw up to other lights, these super throwers exist in the thousands, but none are small or LED, because small LED lights usually aren't what you want when you want throw you really want it, for military, search and rescue, and similar.

The very narrow range of Night Time Base Jumpers, cheap boaters, and flashoholics, that want small LED super throwers does not meet the market demands of being worth it to produce for.

A real good one, would use optics with a reflector, or, be like, a weird shape, with 10 leds that each have their own deep reflector and optic, with a sideways battery and strange handle, and would be just as heavy and bulky and expensive as much better hid short arc superthrowers.


----------



## Bazar (Oct 4, 2017)

The answer here is clear. Lights go up to a rediculous 50,000,000 candela for short arc 300mm hand helds, and portable battery powered all the way up to 100,000,000 candela. LED lights will not do that unless the technology surprises us with a rediculous leap.

And, LED flashlights have yet to really use, a super super deep reflector (cost would be in the thousands, for manufacture and raw materials) which would have to have no flaws at all, and, an optic to top it all off the re-focuses the light to laser perfection. The technology exists but no one has made it yet. And a short arc would probably still do better.


----------



## The_Driver (Oct 4, 2017)

Bazar said:


> And, LED flashlights have yet to really use, a super super deep reflector (cost would be in the thousands, for manufacture and raw materials) which would have to have no flaws at all, and, an optic to top it all off the re-focuses the light to laser perfection. The technology exists but no one has made it yet. And a short arc would probably still do better.



Please read my post above.

The depth of a reflector is not relevant for throw, only the diameter. 

Adding a lens to a reflector will not increase throw, it will at best decrease it slightly (because of lens transmission losses), but probably decrease it by a lot. 

Large reflectors can be made cheaply. The BLF GT a 118mm diameter reflector and only costs 111-200$!

Also the Maxabeam is not made out of silver and does not produce 6000 lumens when defocused (more like 1500). :thinking:


----------



## scs (Oct 4, 2017)

The_Driver said:


> ...
> The depth of a reflector is not relevant for throw, only the diameter....



I'm guessing this statement needs some qualification, because I can't imagine a 600 mm wide by 30 mm deep parabolic reflector will cast much of a beam. Most if not all of the light will not even hit the reflector, if the reflector is wider than the emission angle of the LED.


----------



## The_Driver (Oct 4, 2017)

My longer post above explains why. 
Depth has almost no effect on the area of the reflector (as seen from the hotspot) because the area of a circle increases with the square of the radius. So increasing the depth for a given diameter will make the LED hole a bit smaller, but the increase in reflector area and thus the effect on the luminous intensity (throw) will be absolutely minimal. This can easily be checked by doing some example calculations. 

Of course there are practical limits, but this is all based on simple math and physics.

Interestingly a really deep reflector will actually create a smaller hotspot compared to a less deep one (both having the same diameter). Instead it creates a larger, brighter corona around the hotspot compared to a flatter one. Both will have essentially the same throw.


----------



## ven (Oct 4, 2017)

I would have thought the depth helps focus the LED in the reflector, surely if it was not important to have a deep(and wide) reflector, all reflectors would be shallow to be more compact.


----------



## The_Driver (Oct 4, 2017)

No, it really doesn't.
A deeper reflector might create a more useful beam profile though for throwers. That might be a reason. The spill is less wide and the larger corona enlarges the lit up area in medium distances. 

Also a lot of people mistakenly believe that depth is good for throw. If you want to sell lots of lights you better make that reflector deep and market the light accordingly...


----------



## ven (Oct 4, 2017)

If more light is focused into the hot spot(all things same other than reflector depth), surely the intensity would be greater in the hot spot. 3" wide reflector, one reflector 2" deep, other reflector 6" deep. The 6" deep reflector would surely the light into the hotspot(tighter/smaller) making it more intense due to less loss(spill).


----------



## ven (Oct 4, 2017)

Will have a read up The Driver, i am always keen to learn!


----------



## The_Driver (Oct 4, 2017)

ven said:


> If more light is focused into the hot spot(all things same other than reflector depth), surely the intensity would be greater in the hot spot. 3" wide reflector, one reflector 2" deep, other reflector 6" deep. The 6" deep reflector would surely the light into the hotspot(tighter/smaller) making it more intense due to less loss(spill).




Nope


----------



## ven (Oct 4, 2017)

:laughing: 

Right, i have an OR mule, can make out the hot spot very faintly up close in the wide flood. 




Being p60 size, i also have a reflector same diameter but deeper(obv as one is a mule). How come the reflector p60 throws light much much further than the mule? 

So what am i missing, same diameter, both p60 format, yet reflector or LED is sat further back into it. I know there is no reflector on the mule, but as it does not matter how deep it is...........this should not effect the LED focus..........So what would be the minimum depth of a reflector to give me the same kcd as one that is 6" deep(all things the same, diam and LED etc other than depth).


----------



## The_Driver (Oct 4, 2017)

Your Mule does not have a real reflector. It's dull and I can't tell if that silver part of the body is actually parabolic and if the LED is sitting at the correct height. That is not a fair comparison.

Also you need to be very precise with all of this! They need to have excatly the same diameter and use exactly the same LED in the same bin at the same current with the same heatsinking at the same temperature.


----------



## ven (Oct 4, 2017)

Yes, all things the same, LED etc etc other than depth. The mule is to give an idea of depth(say 10mm deep). I can not get into my stupid head how this would throw light as far as the same yet 50mm deep reflector.

So the mule style, but in reflector, arguments sake both LED's are 219b's. All same width, all driven at 1.5a(everything same). I can not see how the 10mm deep reflector focuses the light as much as the 50mm deep reflector. As with the 10mm reflector..............its not even focused.


----------



## The_Driver (Oct 4, 2017)

But it's true...

The calculation I posted above (post 13) shows this. You can actually calculate the throw if you know all the details. You would be amazed how accurate it is. 
Now just try to think about the equation. Think about how the depth of the reflector will influence it.

Imagine that you are shining the flashlight around outside. Now imagine that you are standing where the hotspot is and are looking straight at the flashlight. What do you see? You see a glowing circle, i.e. the reflector reflecting the light of the LED (and also the LED itself) into your eyes. You cannot really see how deep the reflector is (for a given diameter). So why should it make a difference?


----------



## Bazar (Oct 4, 2017)

The_Driver said:


> Please read my post above.
> 
> The depth of a reflector is not relevant for throw, only the diameter.
> 
> ...



No that isn't what j meant. The reflector has a pure silver coating or rhodium which is more expensive than silver, and from the original maxa beam the 12m candela not the 45m candela one it is 6000 lumens.
100-200$ alone is not cheap. That along with other costs make it way to much money. Raw production cost of maxa beam is so high at 1200$ most would never consider buying one. The original poster's point is to find a 400 dollar light or cheaper that throws well, not the 2000 dollar maxabeam.


----------



## Bazar (Oct 4, 2017)

The_Driver said:


> But it's true...
> 
> The calculation I posted above (post 13) shows this. You can actually calculate the throw if you know all the details. You would be amazed how accurate it is.
> Now just try to think about the equation. Think about how the depth of the reflector will influence it.
> ...



The deeper it is the less you have waisted wash light, ditto for not having a lenses.


----------



## BVH (Oct 4, 2017)

Remembering my 60" Carbon Arc as best as I can, the 60" reflector had a maximum depth of about 9"-12", so pretty shallow I'd say. But obviously it threw like no tomorrow.

Matt from Peakbeam Systems posted on one of the Maxabeam threads recently and I'll try to find it but IIRC, maximum Lumens from the latest gen3 MB is about 1,300 Out The Front.

http://www.candlepowerforums.com/vb...eam-question&p=5053478&viewfull=1#post5053478


----------



## Bazar (Oct 4, 2017)

BVH said:


> Remembering my 60" Carbon Arc as best as I can, the 60" reflector had a maximum depth of about 9"-12", so pretty shallow I'd say. But obviously it threw like no tomorrow.
> 
> Matt from Peakbeam Systems posted on one of the Maxabeam threads recently and I'll try to find it but IIRC, maximum Lumens from the latest gen3 MB is about 1,300 Out The Front.
> 
> http://www.candlepowerforums.com/vb...eam-question&p=5053478&viewfull=1#post5053478



Yes. They significantly reduced the lumens to get more throw, version I spoke of wasn't even short arc and I was wrong, the 6k lumen version had 1m candela, not 12.

Also short arc is completely different than LED


----------



## Bazar (Oct 4, 2017)

Bazar said:


> Yes. They significantly reduced the lumens to get more throw, version I spoke of wasn't even short arc and I was wrong, the 6k lumen version had 1m candela, not 12.
> 
> Also short arc is completely different than LED



I.E. deeper reflector helps LED but hurts short arc.


----------



## Illum (Oct 4, 2017)

optically.... its not possible ruling a monstrously heavy aspheric, you'll simply need a bigger reflector, but there's a practical limit with that.


----------



## The_Driver (Oct 5, 2017)

Bazar said:


> The deeper it is the less you have waisted wash light, ditto for not having a lenses.



A deeper reflector does not put more light into the hotspot. It makes the corona around the spot larger and actually makes the spot smaller. It's rather subjective to say this is always better. Especially since a deeper reflector means you have a longer, heavier flashlight.



BVH said:


> Remembering my 60" Carbon Arc as best as I can, the 60" reflector had a maximum depth of about 9"-12", so pretty shallow I'd say. But obviously it threw like no tomorrow.
> 
> Matt from Peakbeam Systems posted on one of the Maxabeam threads recently and I'll try to find it but IIRC, maximum Lumens from the latest gen3 MB is about 1,300 Out The Front.
> 
> http://www.candlepowerforums.com/vb...eam-question&p=5053478&viewfull=1#post5053478



Yes, it throwsmainly because of the very large diameter and also the somewhat high luminance of the carbon arc (the luminance of the carbon arc is actually very similar compared to the 75W Xenon bulb in the Maxabeam, but much lower compared to the best large Xenon bulbs in the KiloWatt range).

Thanks for the link! 1300 lumens seems very realistic. 



Bazar said:


> Yes. They significantly reduced the lumens to get more throw, version I spoke of wasn't even short arc and I was wrong, the 6k lumen version had 1m candela, not 12.
> 
> Also short arc is completely different than LED



Who is "they"? Peakbeam doesn't offer a light with high lumens. They also never reduced anything. They actually made the Meaxabeam brighter over the years by increasing the power to the bulb and using better reflectors. 



Illum said:


> optically.... its not possible ruling a monstrously heavy aspheric, you'll simply need a bigger reflector, but there's a practical limit with that.



There is actually a point where a large reflector is of no use. The important thing here is the ratio between the diameter of the light source (the LED) and the diameter of the reflector. You only get a higher luminous intensity (=>throw) with a larger reflector if it’s completely lit up by the light source (looks at this picture => the reflector is yellow everywhere => this is important). The bigger the reflector becomes when using the given light source, the more precise the parabola shape needs to be.

The best example of this is the Maxabeam. It has the same size reflector as the BLF GT, but a much smaller light source. The bright spot inside the arc of the Xenon bulb has a diameter of around 0.125mm. Only when the entire surface of the reflector is lit up by this tiny spot in the arc, will the light have 12Mcd. Because of this the Maxabeam has an electroformed precision reflector.

The Die of the Cree XHP-35HI in the BLF GT has a “diameter” (distance from corner to corner) of 2.9mm (size measured here(link is external)), 23x as much. So the reflector doesn’t need to be as precise as the one in the Maxabeam.

LED flashlights usually don’t have this problem because most LEDs are rather large (optically speaking) and the reflectors use are rather small. Common cheap aluminium reflectors are easily good enough for them.


----------

