How to detect rotate in silver light using camera

   I have a silver light control use web camera to capture image.  Browse the silver light page in windows surface, when I rotate the screen, the camera still renders the original picture.

   Such as: first I hold the surface in landscape mode, I access the camera. But when  I rotate the surface in vertical portrait orientation, the camera still renders the picture as if in landscape mode.

Anyone who knows silver light how to use camera render the right picture no matter how you hold the surface?

Thanks.