different gamma levels in jit.qt.grab?

    Mar 09 2013 | 1:52 pm
    i am having a problem here which is driving me nuts: the output of a jit.qt.grab object (live camera) and the file written to disk when using a write message have different brightness and/or gamma settings: the live output is darker then the file written to disk.
    if i feed the jit.qt.grab output into a second jit.matrix and write this one to disk, i even get a third variation but none of these match each other in terms of brightness/contrast.
    i know about this legacy-gamma problem with quicktime but it seems to be something different.
    i tried it with different cameras (hv20 over blackmagix express and onboard macbook pro webcam) but the problem is persistant and reproducable.
    what can i do to solve this?
    thanks a lot for help!