Strange random colored pixels

  • Hi all,
    Sorry, it's not an Isadora question but I'm a little bit lost and wonder if anyone experienced the same.
    I've done a show running like this :
    Live camera -> BM intensity USB3
    tripplehead -> 2 x 1024*768 projectors via VGA
    BlackSyphon -> Isadora Syphon -> QLab
    Using live camera, PhotoJPEG movies and JPEG pics into QLab on 3 three different surfaces.

    Everything worked fine, until one day I had to use only one Projector (skipped tripplehead, direct 1920*1080 DVI output from Mac to Projector)
    I noticed some little random colored dots on my projector. But only when movies or live video is sent, not on JPEG images (I think !). I thought it was a projector problem.

    Two weeks later, back to standard configuration, tripplehead - 2 x VGA 1024*768 - 2 projectors and I had again these little dots. Thought It was a QLab issue, tried to play some movies directly from Isadora or Modul8. Dots are still here.. I though it was a GPU issue.

    Back home today, I tried to plug my mac to my screen (1920*1080 DVI), run the show. No dots...
    Is my GPU dying ?

    Any idea ? Comment ?


  • ey philippe.

    I dont know much of the set up that you mention, but I wanted to share with you that I use a Live Camera connected to the computer via firewire, and when I use a long (10mts) cable, I have some quality loose, and as a result of this, I see some colour pixels once in a while. perhaps this is the direction to search?

  • It doesn't comes from the live capture, because strange pixels also occur when a movie is played.
    But not with static images (jpeg).

    After another show in another theatre, everything went well. The only difference in the setup was the 2 projectors and the output resolution used : 2 x 1280*720 with vga connections.

    Still no idea..

  • Tech Staff

    Sounds like it might be a video card issue... hard to nail down though.