Beam size issues RGB

As my first green machine is now operating (sorta!) .. my mind keeps turning to the RGB system.
One point of confusion seems to be the beam size. Greens abound in the 2-3mm size. Even blues and reds at lower power.
The moment you look at blues and reds over say 100 mw you get a FAT beam. Like 5mm plus
I am quite keen to look at one of Marconi's twin jobs but am hanging out hoping his new four beamer will show up soon.
Obviously the red sets the game plan for the rest of the design (I think) as this is where the money has to go first.
Any ideas ??
How important is it or am I reading too much into fat beams for an RGB given that I do want it to do graphics.
How do you compensate for say a nice 2mm green with a 2mm red and then a 5mm blue ?? how does that translate into white nicely ??
Thanks guys

Ray
NZ

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Originally Posted by Pitts

As my first green machine is now operating (sorta!) .. my mind keeps turning to the RGB system.
One point of confusion seems to be the beam size. Greens abound in the 2-3mm size. Even blues and reds at lower power.
The moment you look at blues and reds over say 100 mw you get a FAT beam. Like 5mm plus
I am quite keen to look at one of Marconi's twin jobs but am hanging out hoping his new four beamer will show up soon.
Obviously the red sets the game plan for the rest of the design (I think) as this is where the money has to go first.
Any ideas ??
How important is it or am I reading too much into fat beams for an RGB given that I do want it to do graphics.
How do you compensate for say a nice 2mm green with a 2mm red and then a 5mm blue ?? how does that translate into white nicely ??
Thanks guys

Ray
NZ

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The first RGB I built the blue was about 1 to 2mm bigger then the rest of the beams. When doing beams you will not even notice it at all. On graphics you will see a little fringing but the untrained eye will not notice. The white is still white because it is so bright the glare covers the fringing.
Now on the second the red is a little bigger and the effects are a little more pronounced due to the fact the eye is more sensitive to red.

actually my red starts off as 5mm but by the time it hits the wall it is the smallest of the three. The 100mW 650nm diode is set up to produce a convergent beam (at first) that beats the blue and green after 2 or 3 meters in terms of diameter.

My red and green beams when combined (with the green attenuated) look just that- red speckles in the air/ beam and green speckles. It's not a yellow beam. I guess it's the fog/ smoke that mixes them due to more photon collisions? I'd really like a pure orange beam, but that cost$$$.
Too bad there isn't an optical "mixer" that could be put in the output to combine them before they hit the scanners..

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Originally Posted by steve-o

My red and green beams when combined (with the green attenuated) look just that- red speckles in the air/ beam and green speckles. It's not a yellow beam. I guess it's the fog/ smoke that mixes them due to more photon collisions? I'd really like a pure orange beam, but that cost$$$.
Too bad there isn't an optical "mixer" that could be put in the output to combine them before they hit the scanners..

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Isn't that what a PCAOM does? :confused:

I find my beams are fairly close at the wall, but my wall is only 8 feet from my projector... :D

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Originally Posted by steve-o

Too bad there isn't an optical "mixer" that could be put in the output to combine them before they hit the scanners..

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You could use fiber to do exactly this.

You mean if I put R/G into a fiber, it would come out yellow or orange??
Can you give details, cost, level of difficulty Dave?
I suppose you have to re-collimate at the fiber end coupler?
How about losses?

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Originally Posted by steve-o

My red and green beams when combined (with the green attenuated) look just that- red speckles in the air/ beam and green speckles. It's not a yellow beam.

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That's strange. My red and green mix together to make a yellow beam, and it's clearly visible as yellow, not red speckles and green speckles.

My guess is that you need to adjust your alignment. Have you checked your alignment in the near and far field? (IE: place a card a foot away from your projector and look at the overlap of the beams, then move the card 15-20 ft away and see if the overlap changes...)

Also, what sort of fog machine are you using? If it's making monster particles (more like dust and less like fog) then that could contribute to the problem.

But seriously, when I mix colors with my RGB rig, I can't see the individual color components that make up the final color. I only see the final color. As an aside, I think the human eye is better able to detect the "fringing" of a mis-aligned optical table than a camera is. For example, most of the pictures I took of my old setup (Argon, Hene, and DPSS pointer, which were *not* very well aligned at all) still showed the mixed color beams, but if you looked with your eyes you could see the two or three individual beams that were mixing together to produce the final color.

If you mix red and green and your alignment is good and the beam profiles are close, you should see a yellow beam, not a partial red and partial green beam. Something is wrong...

Adam

Adam,
In normal air without any fog it looks like top picture. Wish it would look like bottom pic. Will a fiber do this? (I know i need fog)
When it hits the white wall though it is bright yellow.

Steve, you're so good with paint :D
I have what you have in normal air, at least close to the projector. Haven't really looked at it further away. Once the beam starts moving the colors mix.
I contribute this issue to the fact that my red beam is much wider than green and close to the projector. So a lot of particles cross only the red beam, showing red. Since the green beam diameter is still very small the green intensity is very high in the center of the mixed beam. Thus the particles that cross the center of the beam get hit by an ovewhelming amount of green making the red not show that much.

Thanks Zoof :o <blush> :)
Ok moving beams mix. Great. Problem solved. My green is a WL and is about 3mm beam dia :/ The Marconis are of course their fantastic-- what-- < 1mm?
The "illustrations" were from memory at about 6-8 ft. from the projector head where they are approx the same size. Yes my alignment is probably not perfect- some stuff is not bolted down yet:eek: I better get my ass in gear B-4 SELEM! Only got <2 months to go:D
Thanks

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Originally Posted by steve-o

Adam,
In normal air without any fog it looks like top picture. Wish it would look like bottom pic. Will a fiber do this? (I know i need fog)
When it hits the white wall though it is bright yellow.

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What type of dichro are you using? Can you post a picture of your setup?

EO dichro. The ouput looks yellow in the pics but not in real life. The green is not attenuated here so it's 'slightly' overpowering the red.

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You could use fiber to do exactly this.

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Dave,
Would a short fiber mix the red/green like mixing a martini- shake all the photons around together until they're mixed thorougly making for a smooth (but dry) beam?:)

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Originally Posted by steve-o

EO dichro. The ouput looks yellow in the pics but not in real life. The green is not attenuated here so it's 'slightly' overpowering the red.

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Like Buffo said you need to check the alignment in the far field as well to see if you are truly combining the beams or just converging the beams.

Theyre 'spot-on' from the dichro to the field across the street (200 ft)

Laser Sam says: "You'll get light that appears orange or yellow but an actual change in
wavelength due to non-linear effects won't show up except at high power.
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My question is (without going into the photon duality particle/ wave theory) is that you will have elements of both 532 and 658 but not a wavelength inbetween (e.g. 590nm) except in appearance due to photon collision (in fog or contact with a solid or liquid object--I'm assuming)? Or am I missing something or completely out in far left field?
Dave- Is this what you are referring to - a non-linear reaction within the fiber?

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Originally Posted by steve-o

Adam,
In normal air without any fog it looks like top picture. Wish it would look like bottom pic. Will a fiber do this? (I know i need fog)
When it hits the white wall though it is bright yellow.

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I noticed that speckle when the beam is in "normal" air, but if I blast some fog out the beam turns a nice deep yellow.

I'm guessing dust & other airborne matter reflect different wavelength light with differing intensity causing the effect, so I keep my workshop filled with fog 24/7 to avoid seeing it :D

Good idea!
I'll have to try that.
I wonder if that'll work in my yard so the neighbors wont see that mowing is overdue:)

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Originally Posted by steve-o

Theyre 'spot-on' from the dichro to the field across the street (200 ft)

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Thats close to perfect in my book.
I have never noticed it in any of my beams. I am running close to a watt of white light now. 330mw of 532nm,460mw of 650nm and 120mw of 473nm. I will try to see if I can get the same effect as you are seeing.

Well I think i've figured it out. I was looking at the beam with no fog/smoke real close (1 inch) and it's kinda like looking at your tv screen @ 1", you can see each individual RGB 'pixel'. Far off though they all blend together mixing like 1 color. I was just kind of disappointed that on a semi-clear night the beam wasn't more of a yellow or orange -it was kind of a dim gray color. I guess that's normal. I'll have to wait for a foggy night--stupid question tho i guess:o oh well, back to work :/

I would like to figure out how to mix colors using fiber unless too complicated/ expensive.. probably have to deal with numerical aperature numbers and calculations -things I know nothing about:rolleyes:

buy a fog machine!

I'm mainly into outdoor beam-shows! BIG fog machine..

Sorry for my late reply (been busy as hell at work), but it seems that you've already discovered the solution. (fog)

Yeah, really close to the scanners I can sometimes see a HINT of the green and red speckle that you refer too (though never as distinct as your rendering above), but most of the time it's foggy (or dusty) enough in my house that I get the yellow beam to show up even before the light leaves the optical table. Of course, I rarely have the lasers on without also having a fog machine running. (Then too, I have two cats and two kids, so the house isn't exactly up to clean-room standards!) :D

As to your other commend about being mostly interested in outdoor beam shows, I'd caution you to always keep this in mind: If you want to do outdoor shows, you need one of two things - either a *huge* freakin' fog machine, or a *huge* freakin' laser! If you don't have fog, you need power, and lots of it. Sorry, but that's the nature of the beast.

While I love the red beam from my Maxyz module, there's no way I'd attempt an outdoor show with it. (Or even with a pair of them...) You need several watts of red, and at least a watt each of green *and* blue, to even think about an outdoor show. (And truthfully even 5 watts of whitelight can look lame when you're outside with no fog - especially if there is any other light in the area.) Most of the guys I know that do outdoor shows start at 20 watts and go up from there. And damn few of them try to pull off an outdoor whitelight beamshow. Mostly they save the whitelights for graphics, and just use a big argon (or even a DPSS green) to do beams.

On the other hand, if you can control the outdoor venue somewhat (fences, walls, trees, to keep the wind down), there are some large fog machines available that will work even with a modest breeze blowing. You just need to place them strategically to use the wind to your advantage. Big air movers (ducted fans) can also help some. Not exactly a cheap solution, since large fog machines are expensive and you'll still need several of them, but it will probably be cheaper to go that route vs buying and operating a 20 watt laser...

Adam

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do outdoor shows start at 20 watts and go up from there

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Now you sound like the guys at .alt- "Go big or go home"
Actually, surprisingly a 30 mw argon 488nm thru a foggy night and lots of fireworks smoke ( a Jul 4 party) was bright enough (outdoors) to ger a few ooohs and ahhhs, (it was probably for the fireworks) so I'm thinking it's more of a visual perception thing epecially with a nice color like 488. Maybe rods and cones and nite-time perception or sumpin?

Hi Steve-o

Well, doing a backyard laser show for your neighbors is something different. After all, if the lasers don't look great - who cares? It's not like you're charging admission or anything, so the people probably won't bitch about it if the lasers look lame.

Then too, if you really control the crowd... Keep them within a 10 degree arc immediately downrange of the projector, for example... You might be able to get some effects to work.

I, too, like to set off fireworks (the powerballs video in my gallery is ample proof of my pyromania), and I've always wanted to combine lasers with fireworks. But the few experiments I've done in my backyard have taught me a lesson. Namely, I don't have enough power. Not with 40 mw of 488nm blue. Or with 100 mw of 532nm green. Or even with 200 mw of red, 75 mw of green, and 40 mw of blue from my whitelight rig.

I can just barely pull off a graphics show in my yard, but even then the streetlights are a problem. As for beamshows - well, they just don't work in my yard. My two fog machines aren't enough to fill my yard with fog (even with no wind), and you can't always rely on the smoke from the fireworks to provide the rest.

I'm not a perfectionist, but I do like my laser shows to be "memorable", in that they're powerful enough that people say "wow! I've never seen anything like that before!" And I just can't get that reaction with an outdoor show - at least not with my current equipment.

Now, having said that, I know exactly what you mean about some of the guys on alt.lasers. I've heard the "go big or go home" line before, and yeah - it bugs me when they say it. But I understand that they do have a point. In the commerical business, there are a lot of yahoo's out there trying to pass off a 1 watt projector as "outdoor capable". When the show turns out lame, all the producer learns is that "laser shows are lame". So the next time, when a really good laser company comes along and promises to light up the world with 20-30 watts of power, the producer says "go to hell", because he's already seen it and it sucked. But of course, what he saw was some cheezy aproximation of a real show.

While I can understand why the "big guys" in the industry are pissed off about this development, I still can't condone their condescending attitude towards the hobbyist community. (This is why I don't spend much time on alt.lasers anymore.) If they could find a way to get their message across without sounding like a bunch of dicks, maybe they could stop people from bidding on larger outdoor shows until they have the equipment they need to do it right.

I will say that in a *completely* dark room with lots of fog, just about anything looks great. (Even 14 mw of red from a hene, and just 8 mw from a green pointer!) So again, if you can control the venue, maybe you can create some cool effects. But I haven't bothered to try it outside beyond the few experiments I've attempted. I get much better results inside. (Plus it's not nearly as hot inside as it is outside!) ;)

Adam

Edited to fix link. Need to click on the movie camera icon to play video.

OHHH i see. The nearest streetlight from our house is 25 miles away. We live wayyy out in the sticks. Telescope viewing is also good from Floyd, Va. Darker is probably better, then, for outdoor shows.
Re: .alt
Yeah they can come across as assholes. I visit there if I cant find an answer here, which is rare.

I couldn't see your vid from here at work- I'll have to wait till Thu when the DSL is finally connected at the house :)

Steve-o

I just realized that the original link to the powerballs video was broken. Try it now. (You still need to click on the movie camera icon to play it.) It's hosted here in the PhotonLexicon gallery, so you should be able to view it at work. (Well, assuming you can view a movie in Windows Media Player, that is...) Do they have the desktops locked down that tight?

RE: living in the sticks. Yeah, that would help some. I actually live in a fairly dark subdivision. Street lights are spaced out about one every 10 houses or so. (!) But then you've got lights from the house to contend with, plus passing cars, etc. But I can see how living in the country would help.

And yeah, darker is *always* better when it comes to a venue for a laser show. I used to live in the country back when I lived in Wisconsin... That would have been a good place to try an outdoor show. But there's no way I could have afforded it back then. (Sigh.)

Adam

Hi Steve-o;

The "powerballs" are actually 1 inch mortar shells. You know, the one's that look like mushrooms with about 9 inches of green candy fuse on them... You're supposed to drop them into a launch tube before lighting them. The first "pop" that you hear (and see) in the video is actually the lifting charge going off. If I had put it in a launch tube, the pop you hear would have sounded a bit louder (more like a thooomp!) as the lifting charge explosion propelled the shell roughly 100 feet into the air. The delay between the two explosions is caused by the remnants of the fuse burning through the shell to the very center, where it sets off the burst charge.

The burst charge is the *big* bang you hear. Normally a mortar shell isn't nearly this loud, because the burst charge only needs to be large enough to ignite the stars in the head and dispurse them in a symetrical pattern.

But in the case of these shells, there isn't anything inside the head except a whole bunch of powder for the burst charge. So that's why they're so freakin' loud. (Nothing but bang!) In fact, I strongly suspect that these little babies are actually in violation of the spirit, if not the letter of the law regarding class C fireworks. I have no doubt that if you held one of these in your hand it would amputate it at the wrist when it went off. They remind me a lot of the original M-80's from the 1970's. That's a lot of explosive power for a class C firework. But they were purchased legally at a reputable store, so I figure I'm in the clear. (On the other hand, I've never seen them anywhere else, and the store I originally bought them from has been unable to get any more of these things despite the fact that it's been nearly a year since I bought them...)

I've still got 1 box of twenty left. I'll probably shoot most of them this 4th of July, but if I get the green light from our host for SELEM, I might save a couple to bring along...

Adam

Sorry Adam I was deleting to add and then your reply popped up
oh well--

Prev. post:
Adam-
I remember that video- F'ckin AWESOME!!
I too am a pyro-fan.. Done some wild shit in my time
What is the first mini-exlosion B4 the BIG BANG??
That was cool!!

I used to do the pyrotechnics for the band I was in. There was this stuff called concussion powder that came in 2 parts. You'd mix them together, put the powder in a heavy open-topped thing ( I used the ends off of the bass players bar-bells- he didnt use them anymore) and ignite it with a punk. (well i used a small piece of a stranded wire that blew when 120VAC was put on it and )---BOOM!
Ahhh.. the good ole days..

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for SELEM, I might save a couple to bring along...

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That would be awesome.
I cant see this happening around a church..
Uhh- it is out of the city limits?

When your pan is flying it looks like a ufo! I was trying to figure out how to transfer that aerial footage and loop it...
I've set off a few M-80s:D
"mortar shells" as in military with the fragmentation devices removed?
Cool!

For certain the pyrotechnics will only be detonated at the private residence, and then only if I get the green light from our host. (Fireworks are not stricktly legal in North Carolina - at least not to the extent that they are in South Carolina.) But I believe the house is far enough from the interstate that I think we'd be OK. (For sure the chuch would be out for that sort of the thing though!)

Concussion powder sounds cool... Similar to flash powder I'll bet. Got a recipie for that stuff lying around here somewhere, but never got up the nerve to actually make any. (My wife would kill me...)

RE: the flying pan... Yeah - it's pretty damn cool the first time you see it. You can't imagine it flying that high! As for the "mortar shells" - eh, that's just the industry term for them. Technically they're "reloadable aerial shells", but some dude in marketing must have decided that "mortar shells" sounded cooler, so that's what they print on the box.

And technically they are a type of mortar, in that the shell is propelled from a tube that is sealed at the bottom end by an explosion that is separate from the main charge in the head of the shell. But beyond that the shells I have bear little resemblence to actual military mortar shells. (For one thing, the Army doesn't use fuses to light their mortars!) These things have a few tens of grams of explosive that is tightly wrapped in paper. Nevertheless, they are quite powerful. (The bottom of the 1 quart saucepan that was sent flying in the last part of the clip is now bent into a slight hemisphere!)

Basically they're smaller cousins of the shells that professional pyro guys use for your typical 4th of July show. Except that the smallest "professional" shell I've ever seen was a 3 inch, and I've seen them as big as 12 inches. (I've read that they get even larger, but once you get past a 12 inch shell you're talking stupid money for each shot.) These little 1 inchers are toys by comparison, but the design (and the underlying physics) are identical.

Adam

Adam-
Well I hope the private residence comes through then..
Concussion powder is more of a 'knock ya back' thing more than a sound thing- I had a tape recorder going and you couldnt even hear it on the tape, the only thing you could hear is the girls screaming after the shockwave passed:p:D
I think that's when the neighbors called the cops..

speaking of alt.lasers tho--somebody put this up..:)

Hi guys,

Have enjoyed all of your posts... even learned the spectrum of Tampax and Depends pads...
Greatly enjoyed the back and fore as the thread wandered here and there..

All good but guess what !! I am not a lot better informed than when I started this on the actual question of beam size and issues related..:confused:

Have I been hijacked or what ??;)

Anyway enjoyed it all..

Hey whats the thought on Marconi's twin beamers they get good right ups no worry, I am referring to the 'apparent' brightness when compared to 635 units ( with fat beams of course) which is the best way to go ??

Cheers

Ray
NZ

Oh.. hey Ray..we wandered a bit eh?
I got the dual Marconi rig and I like it a lot but I can't compare to 635. My 7 mw he-ne's not running and I dont think that would be adequate for comparison so I cant comment on that. The Marconi's are great, they have a thin bright beam and color mixes well , also heard 635 fat beam and lousy beam quality, FWIW
-Steve

Hi Ray;

Yeah, we hijacked your thread big time. Sorry about that. :o

So, back on topic - which is beam quality... If memory serves, you currently have two high power DPSS green units - a 1.5 watt and a 1.7 watt. To get enough red to mix with that is going to be difficult. Even if you dial the green down to a watt, you're still going to want 2-4 watts of red to mix with it. That really limits your choices, simply because there are so few lasers that can make that much red.

The dual Maxyz module rigs that Marconi sells will only give you around 450 mw. (I've heard of people pushing them to 500 mw, but that is an absolute max.) Even his 4-diode experimental rig only makes 800 mw, which is still way too low for your application. (And isn't available yet in any case.)

To get several watts of red, you're looking at a pair of 635 nm diodes and a PBS cube, or a krypton ion laser. (OK, a DPSS red at 671 nm is another option, but that red is so low in the spectrum that it's hard to see, so you'd need even MORE power.)

Given that the high power 635 nm diodes are really expensive (once you get above a watt) and that beam quality is important to you, I'd say you might want to seriously consider the krypton laser. (Find a deal on E-bay and you might actually come out quite a bit cheaper for the same power level.) Sure, it will be large, heavy, water cooled, and need lots of juice, but the beam quality will more closely match your green laser. Plus you'll be able to ramp your green way up without shooting your color balance all to hell.

Now, if you're only looking to build a low-power RGB rig, then I'd recommend the Maxyz modules because they have very good beam specs and will look great. But that means you only need around 150 mw of green to balance it. Sorta wasteful considering that your weakest green laser is putting out 10 times that much power!

If you go with the 635 nm diodes, you're going to have to live with the large beam diameter. I've seen one 500 mw diode where the beam was so divergent that it spilled off the mirrors of the galvos! (We're talking about a throw of less than a foot, and already it was big enough to spill!)

To the untrained eye the larger beam diameter from that unit wasn't all that easy to see during a beam show, but it was *plainly* obvious when doing graphics - even to a newbie. One solution would be to increase the size of the green beam to match the red. But then you're probably going to want larger mirrors on your scanners...

Adam

Thanks Adam,
You have confirmed my fears..
However, no I don't intend to use the 1.7 and the 1.5 for the RGB.
I think it was you way back that pointed out to me that nothing beats an RGB with two bright green beams on the sides. The big greens are for that job.
I now understand that I need to be more modest with my RGB power (so does the bank manager and "she who would be obeyed" ) .. Probably thinking in the 1 to 1.2 watt area (total). So I would be buying three more lasers + galvo etc.
I guess my concern with the Maxy's is the wavelength (based entirely on my ignorance and a photopic list I have donwloaded from PL here).. the Maxy's look great to me and I am sure they are well made but the chart seems to suggest they will be way down in brightness by comparison to 635. .. But then who wants a giant fat beam that looks yuk ?? ( like 5 or even 6mm)..
Any ideas.. I also like the idea of using CNI's Green and blue. What do you think.
Thanks
Ray
NZ

Thanks Steve-O. appreciated.

Sure thing, Ray
I actually wanted to try a 622 diode, but the best they could do was $500 for the bare diode. (well, w/ the C block.) Just for kicks. But-
635 is a little too orange for good color mix from what I've read. I believe Adam uses 650 if I'm not mistaken. Is that right Adam?

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Originally Posted by Pitts

nothing beats an RGB with two bright green beams on the sides. The big greens are for that job.

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Ahhh yes. I see where you're headed now Ray. OK - that sounds pretty cool. Only problem I see is that if you try to do RGB *beams* from the center projector, they might end up being washed out (overpowered) by the monsterous greenies you'll have on either side. But if you're thinking of doing graphics with the center RGB unit, then you'll be fine.

For RGB beamshow, I think you're going to want more than 500 mw of red, considering how much power you'll have on either side of it. And right now, 500 mw is the absolute limit of what you can get from the Maxyz modules in a dual-laser configuration.

But this also depends on how large of a show you're going to do. Tell me: what sort of venues will you be setting your lasers up in? Are we talking about a nightclub that is maybe 50 ft square tops, or are we talking about something much larger?

In a smaller venue, if you can keep the rest of the lights down low and you have a really good fog machine (or better yet a hazer like the DF-50; see if you can rent one because they're *stupidly* expensive to buy), then you might be OK with 500 mw of red, 200 mw of blue, and 200 mw of green. Color balance won't be great, but the beams will be visible. (Though, admittedly, the greens on either side will still be super bright!) This is a projector that you could put together for a reasonable cost (using the Maxyz modules for red), and it would probably serve you quite well so long as you didn't try to book too large of a gig with it.

On the other hand, if you're looking at setting up in larger venues, or in areas that will have lots of other lighting effects, then you may have to bite the bullet and go with 700-800 mw 635 nm red just to stay visible. Then you could add 250 mw of green and as much blue as you can afford (figure 300 mw as a starting point), and you'd have enough power for a pretty good sized venue. Only drawback would be the larger beam size of the red. (and the greatly increased cost, of course!)

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I now understand that I need to be more modest with my RGB power (so does the bank manager and "she who would be obeyed" )

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I hear you there, pal... (Boy do I hear you!) I ended up with 200 mw of red, 70 mw of green, and 110 mw of blue in my RGB rig. (Well, right now my blue is only making 40 mw, but Lasever is supposed to be sending me a replacement.) So I'm pushing less than 400 mw total whitelight power. And even so, this rig managed to stretch my budget right to the limit. I get around the (relatively) low power problem by always projecting in a completely dark room with lots of fog. Under those conditions, it looks *fantastic*, even in a pretty big room.

But I wouldn't want to try and do a show in a larger venue (like a school gymnasium, for example) using this rig... Even with a ton of fog it would still look lame. In fact, I'm not even sure that I'd be able to pull off a show in a nightclub with this rig - because of all the excess light. Maybe if I only did graphics and no beams it would work... Eh - it's a moot point I guess, because I have no plans to do any commercial shows with my rig. (I'd much rather work with someone else that has better equipment and has already gotten the variance! Then I can learn from them while playing with some really nice gear!)

I've got a second red laser that I could combine to get 400 mw of red, and I might do that later this summer, but for now my color balance is pretty decent. (Plus I'm afraid that once I jump up to 400 mw of red I'll feel the need to bump up the blue to 170 mw or so, and I really can't afford that.) Sigh... Why is green the only color that is cheap? (This really is a money-pit hobby, isn't it?):D

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I guess my concern with the Maxy's is the wavelength (based entirely on my ignorance and a photopic list I have donwloaded from PL here).. the Maxy's look great to me and I am sure they are well made but the chart seems to suggest they will be way down in brightness by comparison to 635.

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It's true that 635 nm is going to appear brighter than 658 nm. However, given that the Maxyz modules have a tighter beam (well, tighter than your average 500 mw 635 nm diode anyway) the power density is higher. That helps to make the beam appear brighter. I've seen 185 mw of 658 side-by-side with around 85 mw of 635 nm with nearly identical beam characteristics, and the two lasers looked about the same as far as brightness is concerned. So as a coarse rule of thumb, 635 nm will look twice as bright. But once you get above a few hundred mw of 635 nm, your beam specs start to go to shit, so at higher power levels that thumb rule doesn't hold true anymore.

Bottom line: I'd put a pair of Maxyz modules up against just about any 635 nm diode up to between 350 mw - 400 mw or so and be satisfied that the two lasers would look aproximately equal in terms of overall brightness. But the one 500 mw 635 nm diode that I've worked with is definitely brighter than a pair of Maxyz modules. Unfortunately the beam is *really* big on that one. (And highly divergent too; over 10 times worse than your average DPSS green.)

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I also like the idea of using CNI's Green and blue. What do you think.

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Funny you should mention that. :o I am currently in the process of reviewing a blue DPSS laser from a member here on the forum. (No, I didn't buy it. They sent it to me to test, and when I'm finished I'll send it back to them. I'm basically doing the review for free, to satisfy my own curiosity. They're paying the shipping both ways, and I'm donating my time.)

I expect to be finished with the review in about a week or so, and once I am done I'll post a lengthy write-up of my findings. While it's still very early in the testing process, I have to admit that I think I've found a laser company that can compete with CNI - excellent quality and a competitive price. Details to follow in a week or two.

Adam

EDIT: PS - Just noticed your post Steve-o. I use the Maxyz module, which technically is 658 nm. It's a very pretty red; it mixes well with just about everything.

Adam,

Once again I am in your debt. I do appreciate all of your effort in these replies, as I am sure other 'newbies' who may read will also find this most helpful.

One of the problems I face is having little to reference 'power' output sizes to being new to the laser game.
Your comments on venue sizes are of real interest as that is part of sorting my system out.

I thought primarily that I would use the RGB for graphics oriented things more so than beams.

The RGB also means I have to buy another QM2000 card (ouch!.. good stuff ain't cheap in this game) to get some control as I can run the two greens of of one card doing the same things, maybe inverted X as you suggested a week or two back.
Also will need to consider high quality Galvos also not cheap.

Look forward to your review on the lasers.

It may pay me to to see if Marconi is likely to produce his four laser job in the not too distant future.

Cheers

Ray:):)

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Originally Posted by Pitts

The RGB also means I have to buy another QM2000 card (ouch!.. good stuff ain't cheap in this game) to get some control as I can run the two greens of of one card doing the same things, maybe inverted X as you suggested a week or two back.

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If you ran a preprogramed show I think you could get an Aelis Blackface ADAT and mod it to play laser shows. Just program everything in Pangolin first. I'm not 100%, but I think this may be an option...

Hi Ray;

Always glad to help. ;) To expand on what Aaron mentioned, another option would be to purchase a Flashback III controller and use the DMX output from your QM-2000 board to trigger effects that you've loaded on the Flashback III's memory card. That would be a little more expensive than an ADAT deck, but significantly cheaper than a second QM-2000 board.

RE: using the RGB rig for mainly graphics. That's good, in that it will allow you to get by with a significantly reduced power budget.

What you may want to try is to build your projector with slightly less power to start with (say, a pair of Maxyz modules, 150 - 200 mw of blue and 150 mw of green). Then see how it performs in various venues. If you find that you're wanting more power, you have two choices: 1) sell the lasers for a slight loss and upgrade to larger ones, or 2) sell the whole projector (possibly making a slight profit because it's completely assembled) and start from scratch on a new one. You're not planning on immediately doing commercial shows, are you? If not, then you'll have some time to experiment with various venues so you can get a feel for what you can and can not do.

Another way you can save some $$$ is to put 20Kpps galvos in the green-only beam projectors. Since they won't be doing graphics, you don't need to have really fast galvos. And once you step down to 20 Kpps the price really drops. Should save you around $600... (And again, you can always trade up later.)

Adam

Once again thanks for the advice guys.:):)

I have decided to buy one of Marconi's twin jobs complete. Then maybe down the track update when he gets the four beam unit sorted.

Adam... I think I will wait until you have posted your review on the blue laser. There seems to be so much trouble with blue at the moment. CNI which seems to enjoy an excellent reputation is quite expensive. Still, I suppose, as we all know there is no such thing as a free lunch... you want good, ya gotta pay !!

Cheers
Ray

Hi Ray;

I'm going to try to finish the testing this weekend. I received my replacement blue laser from Lasever late last week so I plan on doing a side-by-side test of the two lasers. I need to make up a temporary jig to hold everything in alignment first. Hopefully I'll have that done later today so tonight I can do the tests when it's dark. (Some of them need to be done outside.)

Adam