Strongest beam ever :)

Enderman · 2018-05-18T17:56:15.000Z

lawallac:

What current are is your driver supplying the CFT-90? Are you using a wavian collar on this because you need light recycling?

Even with a collar and a perfect focal length lens the most he will get out of it is ~4mcd and 2500 lumens.
Moving heads often do 10-20mcd and about 20000 lumens.
if he wants something that makes a similar beam he will need to use short arc.

zak.wilson · 2018-05-19T01:17:40.000Z

This moving head is a bit under 9 Mcd. 4 Mcd might be close enough visually when it comes to beam effects like this.

Enderman · 2018-05-19T01:26:51.000Z

zak.wilson:

This moving head is a bit under 9 Mcd. 4 Mcd might be close enough visually when it comes to beam effects like this.

Not just candela, also lumens matter.
If you have a 1mm^2 LED making 1000 lumens or a 2mm^2 LED making 2000lm they will have the same intensty and cd/mm^2 giving the same throw (assuming same polar distribution and other stuff).
The second LED will have a beam 2x brighter (initially) because of double the lumens.
The down side is that the beam will diverge more too due to the larger LED area.

ma_tumba · 2018-05-19T11:11:16.000Z

What would the light scatter on? Just air with natural dust? Are you allowed to use smoke to make the beam denser?

MaximeH · 2018-05-19T11:57:41.000Z

Thank you for all your answers !

Iawallac:

My driver is supplying 4.0v / 15A. I can’t get more right now. The LED should handle 4.2V / 27A … I’m not using any wavian collar. We can’t find them anymore, can we ?

ma tumba:

It would be used in a concert hall. Rather dark and with smoke. It would be quite optimal.

Just a quick picture of the first optic. It's on this strange position that I get the narrowest beam (with the 120mm aspheric lens on top)

So what do you think I should do ?

find a more powerfull driver ? (That I'll do)
find some kind of wavien collar ?
work on the first optic ? (maybe a full spheric one ?)

djozz · 2018-05-19T12:13:52.000Z

My feeling is that you should check leaving the first optic out and see what you get with just the 120mm lens.

But if a condensor lens is used to get more light in the hotspot (mind that with it the hotspot will be wider, not brighter), in this position it does not work as a condensor, it is way too far from the led to collect a significant amount of light. I reckon it should be right on top of the led.

Zelda · 2018-05-19T12:16:07.000Z

The connected wire in the picture from first optic looks very thin to me, I estimate around 0.75mm2.
Thats perhaps not enough for suppling 15A+ current to the led? (Depends also on driver type…)

Enderman · 2018-05-19T19:04:00.000Z

Nice setup, here’s what you can do to get the maximum performance in the beam:

1) replace that aluminum heatsink with a NH-D15, you will get MUCH better cooling performance.

2) Use some MX-4 thermal paste between the heatsink and the LED (if you want to go all out, use some Thermal Grizzly Conductonaut liquid metal)

3) Use a more powerful driver. Even though the LED is rated at 27A you can get to 40-50A if you have good cooling like I mentioned above.
https://www.mouser.ca/ProductDetail/MEAN-WELL/UHP-350-42?qs=%2Fha2pyFaduiKYJ07tagxAKyrsCEh8RRLF8%2FREeUojk8YCOnKM04Pfw%3D%3D
Just an example, up to 60A power supply.

4) Remove the first optic and use a wavien collar instead, you can buy this flashlight and rip the collar out of it:

Marinebeam

Marinebeam Ultra Long Range LED Illuminator Flashlight

High Lumen, 700 Meter ANSI FL1 Beam Distance | Over 100,000 Candela

Average Rating: 5

Price: USD 129.95

5) Use an A037 lens instead of the A380. (beam will be brighter but not as tight)

ma_tumba · 2018-05-20T11:33:54.000Z

I wonder if there are “smokes” that would fluoresce under uv light? In this case you could use an uv laser instead of a flashlight. More efficient in terms of beam divergence, brightness and there could be a choice of color, too

Enderman · 2018-05-20T19:29:23.000Z

No there is no fluorescent hazer fluid.
Also a lazer has a far thinner beam making it less visible, even if it is brighter.

lawallac · 2018-05-21T17:12:06.000Z

What color temp of the led is this? I see mouser lists instock the 7800k, stage white, and even 8500k. I would expect these bluer whites to provide greater scatter and a more visible beam.

The_Driver1 · 2018-05-21T20:15:37.000Z

Enderman:

Remove the first optic and use a wavien collar instead, you can buy this flashlight and rip the collar out of it:
Marinebeam Ultra Long Range CREE RLT Illuminator

The collar in that light (probably the small one) might be too small for this LED.

Enderman · 2018-05-21T21:49:51.000Z

The_Driver:

The collar in that light (probably the small one) might be too small for this LED.

What would it be too small?
It has an inside diameter of 25mm, the LED is only 3mmx3mm.
It will have the exact same effect as a larger collar, projecting an inverted image on the die.

MaximeH · 2018-05-22T07:34:56.000Z

Thanks Enderman for all these advices ! I’m gonna test these.
Iawallac, mine is 7800k

Enderman · 2018-05-22T07:45:57.000Z

Good luck, please post results I love moving heads and strong LED beams.

Let me know if you need any help with the collar stuff.

This is the difference between A037 and A380: Optolife review - the best aspheric flashlight lens

The_Driver1 · 2018-05-22T10:13:28.000Z

Enderman:

The_Driver:

The collar in that light (probably the small one) might be too small for this LED.

What would it be too small?
It has an inside diameter of 25mm, the LED is only 3mmx3mm.
It will have the exact same effect as a larger collar, projecting an inverted image on the die.

Because sma, the only guy who actually studied them in detail here , noted this possibilty. He says that they only focus good in the center which might lead to a reduced effect with large LEDs and/or small collars.

Enderman · 2018-05-22T10:43:09.000Z

The_Driver:

Because sma, the only guy who actually studied them in detail here , noted this possibilty. He says that they only focus good in the center which might lead to a reduced effect with large LEDs and/or small collars.

The reflected image is exactly an inverted projection of the die.
It doesn’t “only focus good in the center” in terms of lateral movement.
What he means is that the die needs to be in the center of the sphere such that the inverted image is projected directly onto it.
The projection will only be sharp when it is focused on the die itself, which is why it is important to get the height right and line it up on all 3 axis.
.
This does not mean that the size of the LED or collar matters.
A larger LED produces the same effect, an inverted image on the die of the exact same size of the die.
The reflected image is of uniform brightness, just like the die.
A larger collar performed slightly better because there is a larger distance from the LED to the surface, making surface imperfections less intrusive, and possibly having a better coating due to manufacturing process.

Enderman · 2018-05-22T10:54:23.000Z

The only possibility where having a large LED and small collar would be an issue is if the LED is so large that part of the lens can’t see a portion of the die due to the collar opening.

The red lines won’t be able to reach the lens, making the outer portions of the lens far less effective.

I don’t think this will happen with a CFT90, small collar, and A037 lens but I can double check if OP wants me to.

The_Driver1 · 2018-05-22T13:43:39.000Z

Enderman:

The_Driver:

Because sma, the only guy who actually studied them in detail here , noted this possibilty. He says that they only focus good in the center which might lead to a reduced effect with large LEDs and/or small collars.

The reflected image is exactly an inverted projection of the die.
It doesn’t “only focus good in the center” in terms of lateral movement.
What he means is that the die needs to be in the center of the sphere such that the inverted image is projected directly onto it.

I understand what you are saying, but it’s definitely not what he wrote. I don’t how strongly your translator is changing the meaning.

Enderman · 2018-05-22T20:50:16.000Z

The_Driver:

I understand what you are saying, but it’s definitely not what he wrote. I don’t how strongly your translator is changing the meaning.

If you take the collar and shift it on the x-y plane the image stays sharp as long as the height does not change.

A larger LED is basically this but in all directions at once ^

This is how a spherical reflector works.
It does not become unfocused at different locations.
You can see that the projected image has uniform brightness, it is not any more intense in the center than it is on the edges.
If if was more intense in the center, first of all, how the heck would SMA have measured that (does he have a 0.1mm diameter luxmeter?), and second, that would violate the laws of physics because you can’t concentrate light to a smaller point than the source.
The ideal scenario when using the collar is to have the die image just as sharp as the die (so completely in focus) and directly on top of the die.
As shown below.