Depth of field In Photography is the distance in a photo and its focus point. Shallow in depth of field is the focus point of a photo well the background is blurred. Good depth of field is the depth and length of a photo that is visual and clear with no blur. Some images appear to be sharp well some are meant to be captured out of focus. The closer the lens is on its subject the deeper the background. The three important things in depth of field when capturing your image is the aperture, the focus length and distance from the subject.