Depth of Field (DOF) is the range of distance in a photo that appears to be in sharp focus ... Depth of field is a creative decision and one of your most important choices when composing nature photographs.

We can achieve critical focus for only one plane in front of the camera, and all objects in this plane will be sharp. In addition, there will be an area just in front of and behind this plane that will appear reasonably sharp (according to the standards of sharpness required for the particular photograph and the degree of enlargement of the negative). This total region of adequate focus represents the depth of field.

If you set the camera's focus to the hyperfocal distance, your depth of field will extend from half of the hyperfocal distance to infinity—a much deeper depth of field.

Another important control for landscape photography is depth of field, the amount of sharpness in a scene, from close to the camera into the distance away from the camera. It's sharpness in depth.