Scheimpflug

This is what happens if a 5x4 camera is set up in parallel:
Focused 1/3rd of the way in (the front of the white plate) and exposed at f11 - focus falls away towards the back


This is what happens when the scheimpflug principle is applied:
Focused on the front of the plate (again) and exposed at f11

There is much more depth of field, because the new line of focus runs through the new subject plane: from the front of the book up to the top of the bottle. Like this:


The camera will allow many other movements - one which is particularly useful is a reverse tilt - away from the subject, instead of sympathetic to it. The opposite of scheimpflug. Focused on the edge of the gilt bookbinding and exposed (once again at f11)

You will notice that in all the diagrams - the back of the camera is not upright. This causes the bottle and glass to lean outwards a little. This can be corrected by keeping the back vertical - as in the diagram below.

See the full misery of a technical explanation of the Scheimpflug principle for yourself

Sinar have useful info on their website