Results 1 to 10 of 10

Thread: Multicolor projectors - minimum requirements?

  1. #1
    Join Date
    Jul 2007
    Location
    Knoxville, TN & Huntsville, AL, USA
    Posts
    3,094

    Default Multicolor projectors - minimum requirements?

    OK, for those of you who haven't seen my other posts, I'm basically a newbie just getting ready to jump into this hobby. Right now, I'm in the planning stage (I'm overseas and can't do much else!).

    I'm leaning towards the Pangolin LA Freak package as my interface / controller (I want to be able to control from my XP laptop) and DT-40's for my scanners. I haven't decided on the lasers yet, but I have a couple of good ideas I want to pursue based on what I've already read in this forum.

    So, to get computer-controlled multi-color graphics and beam effects - is it possible to get 2-color effects using only green and red lasers, or is a full complement of green / red / blue lasers required? Also, what additional optics, if any, would be required?

    Thanks!

    RR
    RR

    Metrologic HeNe 3.3mw Modulated laser, 2 Radio Shack motors, and a broken mirror.
    1979.
    Sweet.....

  2. #2
    Join Date
    Jan 2007
    Location
    Peking
    Posts
    1,199

    Default

    Quote Originally Posted by Stuka View Post
    OK, for those of you who haven't seen my other posts, I'm basically a newbie just getting ready to jump into this hobby. Right now, I'm in the planning stage (I'm overseas and can't do much else!).

    I'm leaning towards the Pangolin LA Freak package as my interface / controller (I want to be able to control from my XP laptop) and DT-40's for my scanners. I haven't decided on the lasers yet, but I have a couple of good ideas I want to pursue based on what I've already read in this forum.

    So, to get computer-controlled multi-color graphics and beam effects - is it possible to get 2-color effects using only green and red lasers, or is a full complement of green / red / blue lasers required? Also, what additional optics, if any, would be required?

    Thanks!

    RR
    Welcome!StuKa
    Used green and red laser with TTL mode you can got three color,green ,red and yellow.but used green,red and blue lasers with analog mode ,you can got full color,the only you could do is combine the three lasers to be on beam,you can use pbs cube or dichroic coating.and contorl it through software and drive the scanner.
    wish you got happy at there.
    Best regards!
    Bridge

  3. #3
    Join Date
    Jan 2006
    Location
    Charleston, SC
    Posts
    2,147,488,218

    Cool

    Hi Ryan;

    If you go with analog modulation on your lasers, you will get better color mixing. (Fortunately, the LA Freak / Flashback 3 setup you're considering supports analog color.) With a red and green laser w/ analog color, you're looking at multiple shades of red, orange, yellow, yellow-green, and green. This is the most common 2-laser setup.

    Likewise, if you go with red and blue lasers, you'll get many shades of pink and lavender inbetween the two primary colors. I've only seen a couple systems set up this way. A blue and green mixture offers perhaps the least benefit, since the shades of teal and aqua between blue and green all sort of look the same.

    But as Bridge mentioned, a 3 laser setup (RGB) is the cat's meow. Then you get *millions* of colors to choose from. (For example, you can mix various amounts of red and green to get that perfect shade of yellow, and then add some blue to it to make it even brighter... Endless possibilities!)

    To mix the beams you use a dichroic mirror. Basically it's a piece of glass that reflects one band of wavelengths while passing another band. You'll need 1 dichro for a 2 laser setup, or 2 dichros for an RGB setup. They cost about 45 bucks each from Edmund Optics. (You'll also need an adjustable optical mount for each dichro.)

    You want the beams to be perfectly superimposed on one another. They need to be at the same height, parallel to each other, and aimed in the exact same direction. Alignment of 3 different lasers can be a pain in the ass, but once you get it dialed in you normally don't have to mess with it much afterwards. (The key is to mount the lasers on adjustable mounts. Then you get everything as close as you can with the laser mounts before tweaking the final alignment with the dichro mounts.) There are a few threads here on PL that talk about various ways to go about this process.

    Adam

  4. #4
    Join Date
    Jul 2007
    Location
    Knoxville, TN & Huntsville, AL, USA
    Posts
    3,094

    Default

    Adam -

    Good info!
    SO, now that I know what I need - does anyone have a crash-course available on WHICH specific filter I would need to go with the lasers I purchase?

    Thanks!

    RR
    RR

    Metrologic HeNe 3.3mw Modulated laser, 2 Radio Shack motors, and a broken mirror.
    1979.
    Sweet.....

  5. #5
    Join Date
    Jan 2007
    Location
    Yorkshire, UK
    Posts
    4,557

    Default

    Hi Stuka

    Welcome to the Forum, it's a great place that's full of really nice, err.... Educated and well informed people

    Like yourself, I too started from knowing very little about how to set up a projector. I did have a knowledge of lasers as i'm into holography, so that helped a little, particularly with safety. I also work in optics, so again, I had a little knowledge about lenses etc. but this hasn't really helped much with regard to this particular hobby.

    Could I respectfully suggest that you have a search through all my postings. I've asked some really dumb questions, but they were all relevant to me at the time and I think that you will probably benefit from them.

    A lot of decisions that you will have to make will depend on how much money you have available to spend on this hobby. Things such as optics mounts. You *can* make your own if you enjoy doing that sort of thing OR you can buy ready made ones from suppliers such as Edmund Optics, but these obviously cost more money. Some things you just have to have, such as dichroic filters, there is no money saving tip for these, buy the best you can afford.

    I've used a 12mm thick aluminium plate for my optics table, but others on this forum have used wood, although I wouldn't recommend this long term as you'll quite probably run into heat problems.

    Same goes for a case, i've bought one 'off the shelf', but others enjoy doing that sort of fabrication.

    There's loads of things that you can save money on by doing it yourself. It all depends on whether you have the time and rescources to be able to do them yourself. Above all though, have fun! This is a BRILLIANT hobby and when you fire up your projector for the first time nothing can describe the feeling of seeing all those coloured photons Unfortunately though, it IS a drug and you'll always want more

    I would suggest that when planning your projector you leave enough room in there for a full RGB setup - trust me on this one, you WILL want to upgrade as soon as finances allow!!

    Best of luck, and if I can help in any way from my limited experiences please do not hesitate to PM me or ask on the forums. No question is too daft and nobody will criticise you for asking, we've all had to start somewhere.

    Cheers

    Jem

  6. #6
    Join Date
    Apr 2007
    Location
    Toronto Canada
    Posts
    1,120

    Default

    This is a BRILLIANT hobby

    You forgot to mention.....it's quiet a pricey hobby!

  7. #7
    Join Date
    Jan 2006
    Location
    Charleston, SC
    Posts
    2,147,488,218

    Default

    Quote Originally Posted by Stuka View Post
    WHICH specific filter I need to go with the lasers I purchase?
    Hi Randy!

    Which dichro you buy depends on the layout of your projector. (More specifically, the order in which you combine the lasers.) In turn, this order is dependent on the power levels of the lasers you buy and how important a perfect color balance is to you. However, for the two most common layouts, you need the same two dichros. One that reflects blue (and passes everything else), and one that reflects red (and passes everything else).

    The thinking goes something like this: Green photons are relatively cheap. Red photons are cheap up to a point, and beyond that they're expensive and the beam quality goes to shit. Blue photons are always expensive and should be protected from loss at all costs.

    So, given that a dichro reflects with greater efficiency than it transmits, you don't want your expensive photons (the blue ones) passing through several dichros on their way to the scanners. So lots of people put the blue laser at the end of the chain, just before the scanners. That way the blue beam hits one dichro (a reflect blue, pass green and red dichro - just like the first two listed on that link to Edmund's in my post above) and reflects with very little loss and then goes straight to the scanners.

    They put the red laser in the middle (with a reflect red, pass green and blue dichro - just like the 5th and 6th items in the chart in that Edmund's link above) so the red beam reflects off one dichro and passes through another (loosing around 5% power in the process) before hitting the scanners.

    The green beam is at the start of the chain, and it has to pass through both dichros (thus it has the greatest total loss) before hitting the scanners. But like I said - green is cheap, so you just get a slightly larger green laser.

    The other way to look at this is that once you get above 500 mw, red becomes very expensive - especially if you want to maintain a tight beam diameter. So some folks put the red laser last in the chain and stick the blue one in the middle. This reverses the order of the dichros, but you still use the same two dichros.

    Make sense?

    Adam

  8. #8
    Join Date
    Jan 2007
    Location
    Peking
    Posts
    1,199

    Default

    Quote Originally Posted by Stuka View Post
    Adam -

    Good info!
    SO, now that I know what I need - does anyone have a crash-course available on WHICH specific filter I would need to go with the lasers I purchase?

    Thanks!

    RR
    PM me,I had the dichroic mirror thay you want.

  9. #9
    Join Date
    Jul 2007
    Location
    Knoxville, TN & Huntsville, AL, USA
    Posts
    3,094

    Default

    GREAT info - thanks!

    Randy

    RR

    Metrologic HeNe 3.3mw Modulated laser, 2 Radio Shack motors, and a broken mirror.
    1979.
    Sweet.....

  10. #10
    Join Date
    May 2006
    Location
    Norway, Fauske
    Posts
    1,206

    Default

    If you want mirror mounts, I got 2 left.
    Look here at buy/sell/trade

    Pangolin FB3 QS/LivePro/SMS2Laser
    Riya MultiBus
    Pangolin LD2000 Pro

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •