@SGaist looking at the QCamera example gave me a lot of info to fix my issue.
I was using the QCamera wrongly.
Too many start/stop followed by lock/unlock etc.
Now the image is captured correctly.

Try adding m_imageCapture.setCaptureDestination(QCameraImageCapture::CaptureToFile);.

P.S.

QCheckBox *cam = new QCheckBox(ci.description()); vailableCameras->setItemWidget(lwi, cam);

Hurts my feelings. See https://forum.qt.io/post/486329 it applies also to QListWidgetItem with the only difference that you don't, obviously, specify a column

Hi @michelson !

Yes, i finally found this bug report too, but i forgot to post it yesterday. The table which Yoann Lopes gave (in your link) explains what is possible or not to do : http://wiki.qt.io/Qt_5.5.0_Multimedia_Backends.

Thanks for your help again ! I'll use my camera API then.

Have a nice day !

Thanks for the Tip , will keep digging...