Camera Exposure and imageProcessing Attributes have no effect



  • Hi,
    i am trying to use the Qt functionality for changing shutter speed iso etc. But whatever I use changing the Values (in qml) has no effect on the Picture coming from the camera.

    For example I tried:

    @
    camera.stop()
    camera.exposure.setManualShutterSpeed(1/itemExposuretime.value)
    camera.start()@

    and the effect on the camera is nothing (except the camera is restarting for the time of a blink)
    If I change the same with bridged Objective C code (referring from qml to a Objective C C++ Hybrid Class using undocumented iOS APIs) it changes the ShutterSpeed as requested.

    Is this a bug or did I miss something ?

    Thanks,


  • Lifetime Qt Champion

    Hi,

    Which version of Qt and OS X are you using ?



  • I am using Qt 5.3 and OS X 10.5.8, I already tried it under Qt 5.2.1 and with Windows 7/Mac OS X 10.5.8, Qt 5.2.1/5.3 and Android 4.0/4.2 (all combinations) all with the same result.


  • Lifetime Qt Champion

    Then it's likely between a bug and a missing feature. You should go on the "bug report system":http://bugreports.qt-project.org to see if it's something known. If not please open a new report providing a minimal compilable example that reproduce the behavior. In your case, you should also post your little native test app



  • Most likely the camera simply does not support that through Qt. I have a Qt camera app for three different Nokia OSs and none of them support this.

    You should check with QCameraExposure::supportedShutterSpeeds whether it is possible.

    And of course: always tell what the device is. Someone might already know what it can do.


  • Lifetime Qt Champion

    If the libs used by the backend (and the hardware of course) provides a mean to do it then I would say it's a missing feature.


Log in to reply
 

Looks like your connection to Qt Forum was lost, please wait while we try to reconnect.