• Small problem. I built a fairly simple show recently for a production of midsummer using a matrox triple head 2 go digital edition. I created stage one as left third, two as center third, and three as right third. I built the whole show, and when we got into second day of tech, the image on stage 3 shifted about 6 inches to the right. I figured the projector was bumped by the electrician while focusing so I lined it up and all went well. When I booted up the show the next day the image moved six inches to the left. I was suprised the projector could have moved again so I moved it back. It did it again and I realized it was a software problem, but I don't know where the issue is. It can usually be resolved by rebooting the computer or quitting Isadora, although sometimes this has to be done many times before the problem is resolved. Or occasionally if a quad distort actor on stage three is reset, the problem will solve itself. I don't know why this happens or where in the line the problem exists. The show has already opened and I am out of town. I'm trying to coach the master electrician through troubleshooting but ilthe problem seems to persist. Is this something someone has experienced before? Any ideas on how to resolve it? I'm edgeblending between stage two and three, so its important for the position of the images to be consistent. Please let me know your thoughts. Duncan

  • Tech Staff

    I haven't experienced this, but have only used TH2G a few times.
    What version are you running?
    Since you say that the quad distort being reset can fix things, is it possible that a X setting (of XYZ) are being changed/initialized somewhere that is causing the jump?

  • Running most recent version of Isadora and updated firmware for triple head on mountain lion. Using VGA for all cable runs with vga to dvi adaptors at the triplehead. I don't think its the x setting because the problem exists across all scenes in two different files of Isadora. The reset I was talking about is just turning off visibility and back on to fix it. Although that is not solving the problem right now.

  • Are you using switchres X or just the native display settings?

  • Also - do you have a version of this project with you on the road that you could test?  You could determine if it's a problem in the local hardware talking to the local mac or if its inherent to isadora - don't change your project, just hook up an external monitor to your laptop and see if the problem crops up when seeing the three stages squished into your test monitor.

    This would also help you talk to the production over the phone - having it in front of you visually.

    Maybe also test if it still hapens if you rearrange the stages - ie. set stage 3 to "left third" and stage 1 to "right third..."  see if the problem is coming from your programming or the triple head.

    Is the third projector doing some kind of auto setup when it boots up for the day - trying to reconfigure its resolution and orientaiton etc ?  Maybe a certain order of bootup could solve it - turn on the projector before booting the mac, then starting isadora, etc.  If there's three identical projectors yu could go through themenus and see what is set differently...

  • Just using the native display setting. My problem is the difference is so small its imperceptible unless I'm in the space. Also based on the content and projection surfaces, changing the stsges doesn't let me know if the image is shifted. I've told them to try different boot up orders. I suspect that will solve the problem. I will also suggest checking the menues. Thanks! I'll update when I know something. Meanwhile any other ideas are greatly appreciated. Duncan

  • this sounds like a projector signal alignment issue, with vga connections devices usually rescan the signal and shift them that the signal matches there output

    try to build a calibration setup 
    i suspect that you are working with xga - so it would be a 3072 x 768 px white picture filling the triple head output
    the white gives the device the information that the signal is filling the whole bandwidth 
    try to unplug your signal cables to double check if a shifting appears again whiteout the calibration picture
    i would describe it as an automatic "overscan" calibration, which is not true but perhaps the idea behind