I wanted to mention that you can use an iPad, and probably even a cellphone, instead of a document camera. Here’s what I’ve done: Place an 18-inch stool or other stable object on the desk. Put the iPad on the stool with the camera protruding over the edge. Have the back camera facing down and aimed at your folding surface. Be sure to have the mic off on the computer and on on the iPad. When it’s time for the conference, log in from your iPad and a second time from your desktop or laptop computer. You will use the iPad video only for demonstrating. The computer will be for images of you. When you teach, pin the iPad, and it will look just like a down-facing camera.
Hope this is useful! Jane