I compare two approaches:
- Traditional focusing where the film and lens plane are parallel leveraging the depth of field proportional to aperture so that the near and far subjects are in focus.
- Tilt to focus on the plane of sharp focus which passes through the near and far subjects.
The diagrams below demonstrate each technique:
Traditional focusing techniques may be simpler; they certainly are more familiar. However, not every lens can stop down enough to get both near and far in focus. For my 150mm I needed to set the aperture to f/64 and a correspondingly long exposure. As one will notice, on this mildly breezy day motion blur can be seen in the leaves of the trees.
Tilt focusing introduces some complications; or at least until the technique becomes familiar. Like traditional focusing techniques the depth of field lies on either side of the plane of sharp focus. However, when the lens is tilted so is the plane of sharp focus. Thus the depth of field projects along the plane and perpendicular to it. The second diagram shows this by highlighting the areas in focus.