Projector Image Alignement Changes Each Time Computer Connected

  • Dear All,

    A user wrote this to me "Lately, every time i connect the computer to the projector the out put changes.  For instance, two images that are a foot apart are now overlapping.  No settings have been changed.l, the project had been saved, and yet the output changes.  This is very distressing as I have to adjust the projections before every performance."
    I myself, during the recent Schmiede gathering in Austria, saw the same thing happen. In all my time using Isadora (and even before), I'd never experienced this before.
    Have any of you faced similar problems? I really was mystified by this, as it seems impossible.
    Does anyone have any ideas how this could happen?
    Best Wishes,
  • Tech Staff

    I remember another forum post with this issue. In that case it was a matter of the projector auto calibrating when it was turned on. My only thought related to isadoras output is, is it possible the high dpi screen stuff is changing the output resolution and messing up the projectors calibration. For perhaps a split instance?

  • I have sometime that when I work with VGA, the projector search to calibrate. Normally my solution is to send a full colored screen before to start the beamer.

  • Beta Platinum

    @mark, It is a bit unclear what the actual scenario is in your question. I have had some experiences like this using multiple stages and beamers. Using a 3rd party software to arrange the output i.e. TouchOSC affecting QuadDistort positioning. Using projection interfaces like DisplayLink, that behave in bizare and irratic ways with multiple beamers. Another scenario where somthing like this has happened, is in the settings of Virtual Stage - where multiple instances of the VirtualStage with different resolutions and aspect ratios are routed through scenes and sub-scenes to be finally composited in layers to a Projector input. I think in this scenario, I was able to get all the ratios to settle down and maintain their discrete position, by methodically working through each setting that included a screen resolution, starting with the application preferences. Cheers Bonemap

  • Izzy Guru


    Yes this is actually an issue you often encounter if your image really has to be precise (for example if you are mapping onto something). The solution actually is to send a pure full screen white image when you startup your projector, so the projector calibrates properly and doesn't try to crop away dark pixels at the edge. Lots of projectors also have an auto adjust button, send full white and hit the auto adjust button to get all pixels of the projector.
    Best Michel
  • Beta Platinum

    @michel great tip, thanx