Mitsubishi ML520G71...Red Holy Grail or Flashlight Fail ??

[hakzaw1]

Excellent photo Jordan +2
can I borrow it? lol

[Stoney3K]

One thing I fail to see:

We're trying to tame this beam with the smallest diameter and divergence at distances of over 100ft possible.

On the other hand, when we actually manage to pull that off, we put a lens in front of the aperture to INCREASE divergence so audience scanning can be done safely.

Somewhere, somebody is over-engineering things a bit.

[taggalucci]

One thing I fail to see:

We're trying to tame this beam with the smallest diameter and divergence at distances of over 100ft possible.

On the other hand, when we actually manage to pull that off, we put a lens in front of the aperture to INCREASE divergence so audience scanning can be done safely.

Somewhere, somebody is over-engineering things a bit.

Well, I'm not sure I see it quite that way. The key thing to me would be realising a situation where all 3 colours are approximately the same diameter and divergence in the mid to far field. Fat 635nm reds are already available, but the red fringe around every beam is less desirable than nice clean whites, yellows etc.

[Stoney3K]

Well, I'm not sure I see it quite that way. The key thing to me would be realising a situation where all 3 colours are approximately the same diameter and divergence in the mid to far field. Fat 635nm reds are already available, but the red fringe around every beam is less desirable than nice clean whites, yellows etc.

But fatting up a beam is a lot easier than narrowing it down.

Given that 445 and 638 are already pretty fat (and quite well matched with the right lenses) you'd only need to expand the green to match.

To be honest, I think we're too critical about ourselves, as somebody pointed out before. Audiences aren't going to notice if you have a red halo around your beam if it's moving through the audience fast or a few feet over their heads. Nobody is going to measure your beams with a ruler on the back wall of the venue.

If there is a situation where you really need a clean, round beam (e.g. graphics) you can always clip the complete white beam right before it enters your scanners. When taming down a beam, you'd lose power anyway at the expense of more initial investment.

[steve-o]

The aixiz lens that I mentioned above clips part of the beam off, hence the better beam but less power. If I had a laser diode that made 1 watt and half of it was lost (clipped) to make a better beam, I'd take it . I dont really care anymore about capturing all the light, and a good profile beam at 500mw would be just very hokey-dokey w/ me .. I mean, compared to the 7mw hene's and 20mw argons I used to put on shows with , hell, I ain't complaining . I think we're all getting pretty spoiled

[taggalucci]

But fatting up a beam is a lot easier than narrowing it down.

Given that 445 and 638 are already pretty fat (and quite well matched with the right lenses) you'd only need to expand the green to match.

To be honest, I think we're too critical about ourselves, as somebody pointed out before. Audiences aren't going to notice if you have a red halo around your beam if it's moving through the audience fast or a few feet over their heads. Nobody is going to measure your beams with a ruler on the back wall of the venue.

If there is a situation where you really need a clean, round beam (e.g. graphics) you can always clip the complete white beam right before it enters your scanners. When taming down a beam, you'd lose power anyway at the expense of more initial investment.

Totally agree! If we can achieve a 4mm x 4mm (or even 5mm x 5mm) balanced white beam at aperture with ~1 mRad divergence and a decent power density (Watts per mm²) then I'm sold.

[kiyoukan]

well i have gotten very close to that.
4.5 with a 1.1 mrad.
However i am using custom made optics .
6x setup.
But i kinda look at it like this.
My beam is 4.5mm raw squared.
i can cut the beam down about 20% with less than 10% power loss.
so after i pinhole the beam down and lose around 10% maybe a bit more i get a 3.6 with a 1.1mrad
Not bad for my use. i thought about using a larger FL diode lens so i had a 5.1mm beam to get a 4.08 with maybe around a 1 mrad.
Its been some time from when i had my laser out i made a video but its gone for the moment.
So i will post my findings and see what interest it generates.

[taggalucci]

well i have gotten very close to that.
4.5 with a 1.1 mrad.
However i am using custom made optics .
6x setup.
But i kinda look at it like this.
My beam is 4.5mm raw squared.
i can cut the beam down about 20% with less than 10% power loss.
so after i pinhole the beam down and lose around 10% maybe a bit more i get a 3.6 with a 1.1mrad
Not bad for my use. i thought about using a larger FL diode lens so i had a 5.1mm beam to get a 4.08 with maybe around a 1 mrad.
Its been some time from when i had my laser out i made a video but its gone for the moment.
So i will post my findings and see what interest it generates.

Cool , and the output power after corrective optics is...

I don't think a few decimal points over 1 mRad is too big an issue (as we've discussed, a divergent beam has safety benefits). The key thing for me would be matching the other lasers to the final beam specs.

[kiyoukan]

I would love to give that to you!
But my meter is a diy calibrated meter.
It was calibrated with a 230mw laser against one of jerry lpms.
So i cannot say what the power is.
If i remember right im driving these around 600MA and i will measure my power after diode lens then after c-lenses and then after pin hole just so you can get a % of loss.
I am trying to get 400mw out after all is said and done.
so i think my loss is below 20% total so i should be hitting that mark but wait till i post the results of my testing.
Here is that video i made before in case some missed it.
http://www.youtube.com/watch?v=R9HX9...eo-mustangbase

[VJ AIWAZ]

hey kiyoukan

you have your video set to private