Stacking Projectors

edited June 2014 in MAIN
I'm willing to stack 3 projectors together. i don't have the projectors right now so i cannot do any tests. I thought that i could use 4 millumin instances (1 for each projector and one final) but i don't know if that's the best way to do it.


  • Hello @mano,

    If by "stacking" you mean creating a seamless images with 4 projectors, then you could use the edge-blending feature of Millumin (and you don't need 4 instances).Please read this tutorial for more information.

    If you mean adding projectors at the same place, to gain luminosity, you could use the Slide Editor (with one or two instances like in this tutorial).

    Best. Philippe
  • I assume that what @mano wants, is to create a vertical edge blending of 3 projectors, following your tutorial It's usually what the "stack" term means.
    Maybe the main concern of @mano is about the processor, ram, and graphic card consumption of such a configuration.
  • I mean using 3 projectors to gain luminosity. As you can see at this example.

    I was quite sure it's called stacking :/

    @millumin so I will have to use one instance for each projector right? So I could manipulate each one separately.
  • edited June 2014
    Hello mano,
    use syphon out from the instance where you handle the content and one instance for each projector.
    1. Duplicate "" (CMD+D), so you could run 4 instances
    2. Open Millumin "Content" and toggle this output to Syphon
    3. Open Millumin Copie1 "Projector 1" and put the Syphon Out into a column; Open Millumin  Copie 2"Projector 2" ... etc.
    Now you can manipulate each output.
    If you don´t have right now the projectors use just 3 Monitors to test it. :-)
    It´s working very nice.
    best wishes lars
  • @Lars thank you very much! I'll test it on Monday were my gtx 680 will be delivered.
    Thnxz again
  • Keep in mind that if you're going to project on to anything but a flat surface you can only align the image to one depth - anything closer or further away will become distorted due the different focal positions of the projectors.
  • @lotech I;m going to project on a cement floor 10x25 meters long.. I know it will be oyt of focus at some point but it's not a problem. Although i would like to have the same image.
  • edited June 2014
    Hi mano,

    Another option would be to distribute the signal to a distributor or matrix. So perhaps you'd save power of the graphic-card and processor and you have more of your performance for your compositions and another computing tasks. So it would I accomplish. Like that way....



  • I think that @mano wanted to be able to adjust the geometry of the outputs directly from the Millumin instances, and not from the projectors, isn't it?
  • edited June 2014
    @vbaudron it will not be enough through the projectors. As I said its a concrete floor 10x25 meters. I've got 3 identical projectors equipped with 0.9 lens. The height of the ceiling is 8 meters. So the keystone of my projection will be quite huge and the onboard correction won't be enough I think @CitizenCaine (what a perfect nickname)
  • edited June 2014
    @vbaudron & @mano, you could adjust the sum of warping with millumin anyway. For the finer adjustments to superimpose the image among the three projectors you could use the keystone- and lens-shift correction in each projector. If it is for example a larger Panasonic projector, such projectors have a very exact keystone- and lens-shift correction. Just an idea.
  • @CitizenCaine yes that would be great! But they've got some awful home projectors (3000 L) that's why I have to do the stacking. The only good thing about them is that they are new.
  • edited June 2014
    Hi mano,

    The first proposal of several instances of Millumin is very good and budget friendly but under conditions performance hungry.

    For my suggestion, you'd have to lend a signal-distributor. Under certain circumstances, even these small projectors have integrated corrections.

    Try it on all cases before. Since you have low-light projectors and a very large area to play on. The soil also absorbs a lot of light. Due to the strong projection angle much blur will arise.
  • Hello again @citizencaine,

    So you think it would be better to have a triplehead2go than using my graphic card for all outputs?

    I will use a mac pro using a gtx 680 mac edition card (4 outputs- 2xDVI, HDMI, Display port).
    Here are the specifications for the card:
    • Base Clock: 1006 MHZ
    • Boost Clock: 1058 MHz
    • Memory Clock: 6008 MHz Effective
    • CUDA Cores: 1536
    • Bus Type: PCI-E 2.0
    • Memory Detail: 2048MB GDDR5
    • Memory Bit Width: 256 Bit
    • Memory Speed: 0.33ns
    • Memory Bandwidth: 192.26 GB/s
  • edited June 2014
    Hi mano,

    Try it with your new graphic card, this one is powerful. You will see. Tell us later how it went.

    On my new MacPro I would do it with a Triple Head 2Go. Since I got there the need that two Thunderbolt outputs are for the monitors for the stage direction. On this computer you can indeed connect up to six monitors. However, the connections must be in Thunderbolt version.  :-\" But my Director monitors have DVI ports. And from these ports I can only use up to a maximum of two to this computer, unfortunately. With active adapters it looks different again.

    So even consider the outputs for your director monitors.
  • edited June 2014
    So @citizecaine with the new mac pro you cannot connect, par example, 2 DVI monitors and 4 VGA using adapters? Not even the apple adapters do the job?
    Cause on my next big project -this is not a big project ): - i was considering buying the upgraded mac pro just for that!

  • Hi mano,

    the following link explains the options to connect the monitors:

  • So i see, you need the Apple Mini DisplayPort to Dual-Link DVI adapter and a usb hub.
    Thanks for that also @citizencaine
  • edited July 2014
    Hello again. Today i had the chance to run some tests. So the main problem is that i can have 1 syphon output. So it's not helping if i run 3 or 4 instances of millumin (1 for each projector).

    What i want to do is:
    1.Run Millumin 1 for the 1st projector --> Syphon Out Screen 1
    2.Run Millumin 2 for the 2nd projector --> Syphon Out Screen 2
    3.Run Millumin 3 for the 3rd projector --> Syphon Out Screen 3
    4.Run Millumin 4 using the other 3 Syphon Outputs.
    That will help me to manipulate each projector separately and then (when everything is set) to run the whole project through Millumin 4 using the Syphon Outputs/Inputs.

    So when i use "Toggle Syphon Output" i only get the output of 1 screen/projector.

    @Lars any ideas how i could do that?

    Thank you again

    edit: @Millumin in the tutorial you mentioned need only one output so there's no problem for that.
    you can check also this image if it helps

  • edited July 2014
    Hello @mano,

    As said in my previous message, do not use 4 instances.
    Start by using only 1 instance with 3 screens (defined 2 screens in the output popup), and use the Slide Editor to use the same content on every projector (1 projector = 1 layer). Then map/warp every projector as you want.
    As there is one projector per layer, you can easily hide or show them, and separately set up them.

    If you need really it after trying this, run a second instance.

    Best. Philippe
  • edited July 2014
    Oh yes. I was only making it difficult for myself.
    thanks for that @Millumin

  • I am late to the 'party'. Here are my experiences with stacking:

    When stacking projectors best results are achieved using same type of projectors with the same type of lens.
    ( it is implicit that  the projectors has lens shift - if you can remote control them via a web interface even better)
    One note - It if very difficult to achieve good results with short throw lenses and stacking. Even with certified stacking short throw lenses from i.e. christie it is hard to archive good results fast.

    Use a dvi / vga / hdsdi distributer for handling the signal since you want to send the same to all the projectors.
    (and save precious cpu/gpu cycles for the show )

    Like @lotech said, use it for flat surfaces only. 

    Best regards

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