# how bright and long can spotlight beams get in real life?



## redberet (Apr 2, 2015)

Never seen a powerful one like some posted here irl.
Saw some photos in this forum of 70,000 or so lumen spotlights.
The photos are cool, but are there any photos anyone could show me with no long exposure and other camera settings/photoshop which make things brighter?
One like this one





from a similar distance,
but with closer-to-real life camera settings?
(the picture is beautiful btw, dont get me wrong)

Then I would have a better idea about what powerful spotlights are capable of and whether they are my cup of tea, or whether the brightness and throw distance is not enough for me and I should stick with tight laser beams.


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## FRITZHID (Apr 2, 2015)

Lol, well..... Idk about other people but my maxabeam looks like a fat white laser on spot mode. If you keep searching around, you'll find that some ppl do actually take "as the eyes see it" photos. 
The xenon short arc lights are particularly impressive.
I think you'd be surprised if held one in your hand. Lasers are cool in their own right but lighting up a power tower at 1.5 miles like it's daytime makes one giggly.


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## redberet (Apr 3, 2015)

Can you link to a thread or photo? I can't find any shots from a distance, just from behind the spotlight. That doesn't give a good idea about the beam throw distance and brightness... same with lasers, video of a guy pointing his 5mW to the sky seems like it goes to infinity, as well as videos of people pointing their 1000mW to the sky. But a side photo from a distance shows the 5mW fades away rather quickly.

So yeah, please a link or photo.


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## PolarLi (Apr 6, 2015)

Well, for that particular light, I can tell you how bright or visible the beam was to my eyes that night. And when I say that night, It means perceived brightness will vary with the light conditions outside, not to mention distance to the light.
Anyhow, because there is some vignetting in the picture (dark corners) you can take a straight line from the moon up, now follow the beam to the left where it pass the two bright stars. That point is very close to perceived brightness from the place I was standing, some 400 meters away from the light. The beam will also appear to have the same brightness all the way til it disappears in the sky. 
Color is another thing. It's definitely a lighter blue to the eyes. I will say it's similar to the first 1/3 of the beam in the pic above.
When that is said, I have not compared this light to other "sky beams" so I don't know how it would match up with some bigger xenon units.

Hope this cleared up a bit for you.


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## Onestep (Apr 7, 2015)

What is your intended usage?


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## redberet (Apr 10, 2015)

PolarLi said:


> The beam will also appear to have the same brightness all the way til it disappears in the sky. Color is another thing. It's definitely a lighter blue to the eyes.


 Thanks, this is really valuable info. If the beam appeared to you to be then same brightness all the way until it disappeared, and you weren't looking straight from the back of the spotlight, than that means it went pretty far before fading. Same thing with lasers.


Onestep said:


> What is your intended usage?


 The project is to create a nest of beams shooting from one hill to another hill on the other side, for the view from the small town in the middle, total distance is 3 km from the hill to the mountain. I can already do that with lasers, know how to build ones with enough power and know the the required paperwork/govt permission. But powerful laser beams, while can look pretty bright even after 3 km, are comparably thin beam. If spotlights can be built to have the same throw distance and remain bright enough, they might be more eye pleasing because of their fatter beams. These lasers at Avicii's show will explain better what I mean by nest of beams



Of course outdoors an at that distances the beam doesn't look as bright. I'm still trying to figure out what spotlights are capable of and whether I should switch to them for this or not. I'd also want to have different colored beams, so I'd need to filter some colors which would cut some of the brightness as well. And of course then there's the cost of building a single spotlight which can shoot this far if every other criteria is met. Laser parts have dropped in price recently, it's more about the long time it takes to build such devices.


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## FRITZHID (Apr 10, 2015)

Using any color filter is going to dramatically reduce output of any white light source. In that aspect, laser is far superior to xenon or any other spotlight like device, the only way I've heard this combated is with color specific LEDs and the use of projection optics, but I'm not thinking that LED will hit the distances you need. I'm not sure what the minimum x° that LED+ optics can preform at currently, not to mention, bigger light source = fatter beam.... hence why xenon S.A. is ideal for long, thin, bright beams, small point light source.


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## redberet (Apr 10, 2015)

Thanks. Even if 80% of the light is lost by filtering, it might still work. Depends more on how much the xenon spotlight beams diverge and look after few km, not just few hundred meters. For lasers it depends but will be around 10 or so meters in diameter after few km, which is still kind of thin when the beam is viewed from few hundred meters below and very thin where it starts which is another reason I'm thinking of trying spotlights. Lasers are easier to animate with tiny and fast galvanometer mirrors but I don't need animated beams this time either.


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## FRITZHID (Apr 10, 2015)

80% huh? That's like looking at it thru a welding helmet.
You'd never see that beam at that percentage.
Tbh, for what you're trying to accomplish, laser is your best bet.
Espc for color.
LED won't project that far without insane power and die(beam) size.
Xenon won't do color very well.

Perhaps a focus mechanism for laser so you can get the spot size you desire at x distance?
I don't see a way for you to get the light amount you need, at distance, in color..... unless you want to jump into insane S.A. wattage.... +2kW minimum with color.
Ecycle old movie projectors or theatrical spotlights Might do it.... Idk.


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## redberet (Apr 10, 2015)

FRITZHID said:


> unless you want to jump into insane S.A. wattage.... +2kW minimum with color.


 Yeah, that's what I had in mind. I don't know much about high power LEDs, all I've heard is the size of the emitter and angle of the beam will require a giant focusing lens and the power per cubic cm will still be comparably weak (in other words, a focused beam might be possible, but a very fat but dim one). Are there even coherent high power LEDs to consider them over say xenon though? I've only heard lasers being coherent until now.


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## FRITZHID (Apr 10, 2015)

Um.... in answer to your laser statement....
L.A.S.E.R = Light Amplification via Stimulated Emission of Radiation.... in layman's terms, coherent light. That's What a laser is. Light of one frequency (nm) in which is 'naturally' collamated (sp?).
Hence why the nice, tight, (usually*) single color beam.

*argon/argon ion lasers can be spectrum fractured to produce several spectrum lines of colors


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## redberet (Apr 11, 2015)

I didn't ask (state) about lasers, but LEDs.


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## FRITZHID (Apr 11, 2015)

My point was lasers naturally do what you need. Spotlights do not. Even with fancy optics, filters, etc.... you're not going to get the same effect with white light sources, espc when you start filtering to achieve diff colors.


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## redberet (Apr 11, 2015)

I guess I need to be more clear myself then.
I'm posting this here because I'm not sure if lasers would be a good choice for this or xenons, or something else you can suggest.
My reasons boil down to this:
While lasers aren't very expensive, if you need wide, fat beams, the laser which is bright enough for a thin beam will become dim when fattened, the extra cost on large ar optics to fatten the beam and price of much higher power (50W+) laser to not be so dim when fattened might make xenon lamps/other + color filters more cost effective. Besides, if you want fat beams, using laser seems counter intuitive since they're good for the exact opposite, thin beams.

Now if no spotlight can have a throw distance of 3 km than that's another story and I'll have to limit my project with what our current technology allows and go with thin beams (lasers).


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## TEEJ (Apr 11, 2015)

redberet said:


> I guess I need to be more clear myself then.
> I'm posting this here because I'm not sure if lasers would be a good choice for this or xenons, or something else you can suggest.
> My reasons boil down to this:
> While lasers aren't very expensive, if you need wide, fat beams, the laser which is bright enough for a thin beam will become dim when fattened, the extra cost on large ar optics to fatten the beam and price of much higher power (50W+) laser to not be so dim when fattened might make xenon lamps/other + color filters more cost effective. Besides, if you want fat beams, using laser seems counter intuitive since they're good for the exact opposite, thin beams.
> ...



Spot lights with extremely tight beams exist, but even the best of the them have far more divergence than a laser, say around 1º - 1.5º.

So, if you plug in 3 km, the beam is quite fat compared to a laser, by a wide margine literally and figuratively....and while a maxabeam, etc, has a somewhat dowel-like in profile compared to a std flashlight beam, it will still be fanning out into a cone-shaped beam over distance.

The intensity of the spot beams compared to a laser also means that there would need to be moisture or particulate matter in the beam path, sufficient to get an air-glow effect.


Using beam expanders for the lasers to make the beams fatter might be the way to go if feasible...compared to the cost of the spot lights that could get close in performance.


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## FRITZHID (Apr 11, 2015)

If I had some colored gels to work with, I'd drag my maxabeam out and snap some good pix for ya so you can see the degradation with filters. 
Theatrical spotlights have color options but idk what kind of distances they can achieve. Member BVH may have more insight on this.


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## redberet (Apr 11, 2015)

TEEJ said:


> Spot lights with extremely tight beams exist, but even the best of the them have far more divergence than a laser, say around 1º - 1.5º.


That doesn't sound that bad to me.



TEEJ said:


> Using beam expanders for the lasers to make the beams fatter might be the way to go if feasible...compared to the cost of the spot lights that could get close in performance.


I think with laser it will be around $10,000 per beam then. Any ideas around how much a spot light with a filter will cost?


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## Mr. Tone (Apr 11, 2015)

Here are current prices on new gen. 3 Maxabeams. http://www.brightguy.com/Maxa+Beam/Maxa+Beam+Package+MBPKG-B 

You could get one of these and try appropriate color filters to see if you get the effect you are looking for. My guess is that nobody here has tried to accomplish such a task yet. I was very shocked at the loss of output on an Eagletac LED light that I had with multiple color filters. When putting on the filters it was a very significant amount of output reduction. However, the beam was not very tight like the type of spotlight beams you are referring to with 1 degree or so.


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## SemiMan (Apr 12, 2015)

At 3KM, 1 degree divergence means a 50 meter spread. Unless the air is unnaturally high in particulate, from a few hundred meters below, that would look at best as a slightly bright haze. You would actually see it easier farther away.


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