Depth of field

Depth of Field (DOF): The zone of acceptable sharpness within a photo, stretching from the closest to the furthest points that appear in crisp focus. When working at close distances under a copy stand, depth of field shrinks dramatically to a sliver just millimeters thin. This thin focus window presents a major challenge when digitizing wavy documents, curled film strips, or thick books that dip into a spine binding. Balancing your aperture is vital: closing it down increases this sharp window to cover physical surface changes, but stopping down too far will run your image straight into the softening effects of diffraction blur.