I don't know anything about view cameras and have never even seen one used. I understand that you can look at the back of the camera and see the image upside-down on the ground glass, and then you use that to focus the camera.

So that means the lens is focused on the ground-glass surface. So how, when you put in a film holder and retract the darkslide, is the lens focused on the film then? It would seem that due to the thickness of the film holder, it would be in front of the ground glass surface. Do you remove the ground glass before inserting the film holder?