Super-Visible Beam/Vertical Column of Light Project

Other Types of Lights LED Spotlights
1

Hello everyone,

I’m a noob but have been lurking for a while. I’d like your advice on a project I’m planning. I’m sure others have more experience with this than me. What I want is a vertical column of visible light, i.e. a super-visible beam. It needs to be immediately noticeable in high ambient light conditions since it would be included in a Christmas lights show. And, there’s a street light within 150’ (50m). It needs to be most noticeable at an altitude of 27 ft to 250 ft above ground level. Is something like this possible with a budget around $200 US? If so, what’s the best strategy considering the budget?

Goal: Most noticeable and visible beam possible for $200 or less
Size: N/A, fixed installation, could be the size of an arc-light, who cares
Weight: N/A, fixed installation
Beam width: ideally 5 degrees
Available Power Supply: 10-20 amps @ 120vac, or 30 amps @ 220vac, 60hz (I have both available to drive power supplies & converters/drivers, etc)
Throw: not really important since this will be mounted vertically.
Color: “white” …whatever is the most visible
Distortion/Rainbows: doesn’t matter
Heat sinking: not a problem, I can build a giant one the size of a trash can and add a 400 cfm bathroom “fart-fan” if necessary.

I’ve been looking at several projects. Both the ” dollar store trash can” and the “speaker box” fresnel lens projects look interesting. Would an inexpensive fresnel sheet-lens and multiple “100w” COBs (possibly combined with 60-degree reflector-lens setups) get me where I need to be? As long as I stay within budget, this project could have as many individual “elements” as the $$$ will allow. And they could be grouped together, or set at any spacing that produces the overall effect.

Would some other strategy work better for the $$$ ?

Thoughts and recommendations welcomed. Thanks!

2

Have you looked into just building a carbon arc torch for a light source?

Failing that, the fresnel lens idea with the cob emitter s should do great. The light visibility will have to do with some of the reflectivity in the air, a fog machine may help with that at lower levels. Good luck and let us know what you come up with.

As always, we will want beamshots….

3

OK, I’ve been digging deeper into this rabbit hole…

As awesome as LEDs are, I’ve determined that they may not be the best solution for this project. In terms of budget, I think I can get a lot closer to the goal by using a metal halide HID lamp and an 18” parabolic reflector. I found a project over on CPF where the guy made his own 24” reflector from foam & fiberglass. It was lined with chrome tape from an auto parts store. So, not exactly the best reflector in terms of optics or efficiency. Yet he was getting the type of beam results I want with a 100-watt HID. And his 400-watt HID was what I’m looking for in terms of beam visibility. The 400-watt MH-HID lamps I’ve seen so far are rated at about 36,000 lumens. And those are brand-name lamps like Sylvania and Lithonia (and I personally know the engineer that used to head the photometric lab at Lithonia, so that’s probably an accurate rating and not “internet lumens”. 36,000 basic radiated lumens ain’t a bad start. And I can get that for about $100 shipped from 1000bulbs. (still comparison shopping though). Plus, better quality aluminum parabolic reflectors are now available for under $100 US. I found an 18” listed for around $60, which seemed to be the best deal for the money. NASA Searchlights uses 18” reflectors in their commercial rigs, so that’s probably enough for this project.

Now here’s where the fun begins. For a few dollars more (insert Clint Eastwood meme here), I could step up to a 1,000-watt MH-HID. That would put me in the $150 range for the lamp, ballast, base, and shipping. But it would get me around 110,000 base lumens! I could probably make a searchlight out of a trash can lid with that kind of power.

So, I may end up asking the MODs to move this thread over to the HID forum. But here’s what I’m thinking so far…

18” Edmund Scientific aluminum parabolic reflector
400-watt MH-HID lamp (or maybe 1kw ???)
custom-built enclosure and focal length/focusing rig
Some sort of shutter mechanism (probably made of steel to deal with the heat)

The shutter will be necessary because the effect I need is “instant on”, and that’s not possible with HIDs. The goal of the beam-effect is to punctuate the crescendo of the song that the Christmas lights will be choreographed to. When the song reaches the crescendo, what I want is BAM! INSTANT 1,000 FT TALL TOWER OF LIGHT! The effect will only need to be seen for about 10 seconds. Then it needs to be gone, because the song fades down and the lights will too.

OK, back down into the rabbit hole. Gotta explore the effect of arc length on beam width today.

4

You might have a look at what djozz is doing with his fresnel lens thrower build. That looks to be relatively cheap and portable…

5

Already following!

FYI:
I’ve decided to shut down this thread and possibly re-post in a different forum. In the last few days, I’ve gone down the rabbit hole on LightSward’s HID-based parabolic reflector spotlight projects over on CPF. They look very promising. I think MH HID will be the only way to get enough lumens to achieve my design goal within my budget.

6

9 months later……

I’m finally back after months of Halloween, Christmas, and IRL getting in the way. Regarding this project, HIDs are no longer an option. When my professional Lighting Engineer relatives reviewed my proposal, their response was “DON’T F$%^g DO THIS!!!” HIDs do not play well with sketchy reflectors like the Edmund Scientific “salad bowls”. Any light that reflects back into the arc chamber can cause them to explode. In fact, HIDs don’t play nice at all. They’ve killed people. And when the correct PPE for changing a lamp involves body armor… yeah.

Soooo… round two: a lot more research and a few new projects to follow. I’ve been looking into LED-based solutions. Most notably Enderman’s Lightcanon project. Other than the Wavien collar, there’s no unobtanium in the design. He used an XP-G2 and a FasTTech 100mm aspherical lens https://www.fasttech.com/products/1606/10002523/1583700. His followup project used an Osram black flat and a better lens.

Since the Wavien is now basically unobtanium, I’m wondering what sort of result I’d get with a mildly overdriven Osram CSLNM1.TG (flat white), no collar, Intel heat sink, and the cheap FasTTech lens? Would there be enough visible beam to make building & bundling 5-10 of these together into an array worthwhile? Size is not a problem with this build, but cost is. I can save a few bucks by omitting the batteries and using either an off-line (120vac source) constant current driver, or a conventional driver and an off-line constant voltage power supply.

Enderman, Djozz, your thoughts?

7

For beam visibility you need to put a lot of these modules side by side. Think 7+ in a hexagon shape like a E07

Do you have a C8+ with a flat white? Imagine holding 7 of them and seeing the beams in the air. They beam won’t be super bright but should still be something to behold.

8

one problem is, if the air is dry, and ‘too clean’, it is hard to see any visible light

it has to reflect off something to come back to the person on earth

usually that is dust or water vapor drops

green is the color the eye sees best, and yellow

so i would say green laser, but they are not very wide.

9

Sunnysunsun:
Yes. But instead of a 7-up TIR where the beam angle is 5-10 degrees each, I’m thinking 7 (or more) Enderman Lightcanons/Optofires The OptoFire Searchlight | BEAMSHOTS on page 3 | record-breaking aspheric LED thrower Something like this:

The problem with Enderman’s builds is that they both used a Wavien collar. According to Enderman’s posts, that boosts the Lm/Cd by 2-3x on an XP-G2 or Osram black flat. But Wavien collars are now pretty much unobtanium and were always $$$$. So, is there a way around that bottleneck using a more modern (yet affordable) led and reflector with a sufficient lm/cd? One that would still work with the cheese-grade Fasttech 100mm lens? https://www.fasttech.com/products/1606/10002523/1583700

We shall see.

A recoil design using a very large parabolic reflector would be a better idea. But all of the affordable reflectors (Edmund Scientific, kids toys, solar collectors, etc) have been tried and have failed. Bad optics = salad bowls. And for the price of a quality electroformed reflector ($2,000 US), I could just buy a used single-head SkyTrakker, or a big DMX moving-head and be done. But I don’t have that kind of cash. I have seen large glass reflectors listed on Ebay, but they’re still $$$$ and I haven’t seen anyone use one yet. And for me, that’s too much money to risk. here

I have already tried a cheap “page magnifier” fresnel lens like the ones used in COB projects on YouTube. Using a 300-watt halogen worklight as an emitter, I could focus the hotspot down to the size of the bulb itself. But I couldn’t columnate the beam or more importantly, see it. Made a great flooder and an ok thrower, but utterly failed as a beamer.

I also have an ADJ Pinspot II stage light. It’s got a “3-watt led” of some sort and uses both a TIR and a plano-convex lens. But it’s best beam angle is 6 degrees. On a very foggy night, I can see its beam for about 1000 ft (300 meters). But on a clear night, nothing. The beam is not columinated and is not intense enough. Makes a good thrower though… if you want to light a disco ball.

10

wle:
Yep. And Colorado is a desert. Our relative humidity is often below 10%. We do have dust and smoke, but not usually in December. And counting on fog or a blizzard is cheating. Even a street light makes a beam in those conditions.

11

How about using some sealed beam headlights from an old car?

12

I don’t think that would do it. Based on other projects I’ve seen, what I need is a super-tight columnated beam with the highest intensity I can get… times as many as I can squeeze into the budget. I know that a recoil-parabolic reflector design would be best. That’s what the Sperry/GE carbon arcs used. The problem there is cost. Every inexpensive large parabolic reflector project I’ve seen has failed because of the reflector optics. Pot lids, kid’s toys, solar cookers, satellite dishes, Edmund Scientific 12/18/24”, that thing LightSword made… they all have the columnating ability of… a pot lid. And car headlights are basically designed to spread a beam about 40’ (10m) with a throw of about 150’ (100m). Great for illuminating a road, but not great for a searchlight. Though I do appreciate the suggestion!

I’m looking for a throw of 3,000’+ (1km), with enough intensity that people can see the beam on a clear night. (Jamie wants big beam.) Enderman’s aspheric lens projects (Lightcanon, Optafire) achieved that throw. But not the intensity. They used 100mm and 120mm lenses respectively, which is big for a flashlight but tiny for a searchlight. However, the overall design was simple, effective, and inexpensive. The only piece of unobtanium was a Wavien collar, which concentrated the led intensity by 2.2x. But that was with an XP-G2 and an Osram black flat. LEDs have come a long way since then, and the Wavien may no longer be necessary. Likewise, since my goal is not max lux in the hotspot or max throw, I may be able to use a larger but less intense LED source that has higher overall lumens.

So here’s my plan as it stands:

  1. Continue down the research rabbit hole for a bit, then compile the results and filter for the best combination of stock parts for use with the 100mm lens. (Did I mention I’m a data analyst by profession?)
  2. Build one 100mm aspheric using those parts. Keep the costs and parts-count low and refine that design.
  3. If its successful at a small scale, that becomes the basic unit for the large project. Then I can build more and just bundle them together into a giant modular array.
  4. That would allow me to build additional elements as my budget and schedule allow, instead buying a single big expensive reflector and hoping I succeed.
  5. And, ya know… a 2m diameter “flashlight” powered by a 4kw generator is portable, ain’t it? I’ll bet I can fit it on a 4’x8’ utility trailer.

Now I just need a cool name for this project…
Light-A-Ray? (Larry)?
Big Lumen F-er (BLF)?
Finger of God (ok, maybe I’ll save that one in case I ever have the budget for a Sperry carbon-arc)

13

OK, parts are on order. Here we go…

I’m going to start with an Osram CSLNM1.TG and a 3 amp CC single-mode (100%) driver from Mountain Electronics. That seemed to offer the best combination of die size, intensity, and cost for a thrower. For power, I’ve got a Mean Well 3.3v 60 amp off-line power supply. The lens will be the Fasttech 100x30mm borosilicate plano-convex aspheric (cheez-grade, but less than $8 each). And the host will probably be a 4” (100mm) pvc sewer pipe. The only thing I haven’t decided on is the heat sink. I know a fan colled cpu heatsink would work. But a decent one is around $25. Which would mean $175 in heat sinks alone if I build the large array. I think a better option will be a custom-fabricated liquid cooling system. I can make that out of copper plumbing fittings and a fountain pump and just flood-cool the heat sink. But to start, I think I’m just going to use a big block of 6061-T6 Uh-LOOM-uh-num, because I have one out on the bench right now.

Should be fun. Stay tuned.

14

I hope you have fun here, Dr scott Diabolical - Evil Genius!

That is quite a username to type in.

15

Well if all else fails there’s this open option……… :laughing:

https://www.searchlightsofsandiego.com/rentals.html

I mean if ya really wanna attract extra attention to your unit first of course. :slight_smile: :open_mouth:

PS. The FAQs are an interesting read.

16

Well, this definitely sounds like an interesting build. Will this be able to light up low hanging clouds? I remember when I was little, I used to see pretty fat beams of light from VERY far away shining into the clouds. I would often see them around Christmas time, but I never got to see one in person so I don’t even know what they look like. Every time I saw one it would be literally at least a mile away. I’ve always wanted to do that, shine a very bright light into the clouds. I’m thinking your build will likely be able to light up clouds. Perhaps not to the extent of those batman signals I saw as a child, but definitely enough to eek out a chuckle in awe at least, since some of my flashlights are able to just barely light up the very low hanging ones. It helps that they’re white so they’re very reflective.

We will want beamshots of your build, by the way :slight_smile:

17

Yeah. but you’ll never confuse me with anyone else.

18

I actually found a single-head 2kw SkyTrakker for sale for $1,795. They didn’t say what was wrong with it. Or, how much time the lamp had on it. But to me, $2k for a light is the same as $20k for a light. I ain’t got that much. So neither is possible right now. …still, there may come a point in my life when I become the custodian of a 60” Sperry carbon-arc. It could happen. I have a plan.

19

That is the goal. Now to be fair, I can already light up “low hanging clouds” with my little 700mA pinspot stage light. But only when they’re 300 ft AGL (about 100m above ground) and it’s foggy. I want WAY MORE than that. I want you to see that beam in spite of the Christmas lights, and street lamps, and clear air. I DO want to draw attention. I do want people to see it from miles away.

Fortunately, I live in a little farm town in eastern Colorado (the uncool flat part, not the mountains). Folks out here would think a big light was “badass”. Also, I’m super-mindful of my neighbors. I only run the animated portion of my Christmas display once every 15 minutes, between dusk and 9:00 PM. I do not intend to become “that guy” with the too-big display that creates hassle, traffic, legal issues, etc. for his neighbors. When my Christmas display gets big enough, it’ll move to a commercial location and will be a drive-through experience. Likewise, I’m very mindful of aircraft. I live directly under one of the approach patterns to Denver Int’l Airport. When it’s in use, the searchlight will not be operated. Simple as that.

20

300 feet AGL? sounds more like fog to me :stuck_out_tongue: You’re lucky to have such low hanging clouds where you live! I’m talking about Cumulus clouds. The fluffy, white cottonballs that are several thousand feet up in the sky. (I think by definition, “low clouds” are anything under 6,500 feet) obviously with fog being excluded as that’s a ground level cloud. Anyway the point is I can already hit the very very low hanging cumulus clouds just barely, but I’d love to maybe build a big spotlight that could easily and very noticeably light up clouds several miles up in the sky. It sounds like what you’re building might be able to do that. The carbon arc really is a marvel, that thing can light up ANYTHING!

That last part you mentioned about being mindful of aircraft reminds me of a friend of mine who recently acquired a laser he had lost in the past once again. He sent me a video where he was pointing it around at the sky and then he pointed it straight into a passing commercial aircraft! :person_facepalming: I was like dude do NOT do that! Not only is it illegal, but it’s very dangerous. He took it as a joke and I was like you do realize that there could be potentially 200 people on that flight, right? Now I’m not saying a laser pointer is gonna cause a plane to crash, but still… have some common decency.