So: first rig up some kind of a tripod system. Then take a picture of the scene with the camera app, with the flash disabled. Finally, run a little script that waits 5 or 10 seconds then takes a picture, something like Code: sleep 5 gst-launch v4l2src ! ffmpegcolorspace ! pngenc ! filesink location=$1.png Ideally, you should add a gstreamer command line at the end to play the shutter sound, so you know the photo has been taken...
sleep 5 gst-launch v4l2src ! ffmpegcolorspace ! pngenc ! filesink location=$1.png