You mean the call to QGraphicsView::render() ?
Well, I want to copy the contents of my scene, or to be more precise: I want to render my scene as it is shown by the view into an image . Eg. a qImage, or a Printjob could be such a target.

What I found out meanwhile is QGLWidget::grabFramebuffer(), which partly does the job.
The big disadvantage of this funtion is that it just gives you exactly the resolution of the QGLWidget as it is shown.