Depth of Field

Depth of field is the distance between the nearest and farthest objects in a scene that appear acceptably sharp in an image. 
The DOF is determined by the camera-to-subject distance, the lens focal length, the lens f-number, and the format size or circle of confusion criterion.
If you desire to have the entire image sharp, a large DOF is appropriate. 
In other cases, a small DOF may be more effective, emphasizing the subject while de-emphasizing the foreground and background. In other words, the smaller the Depth of Field, the more emphasis there is on one given subject. 

For a given f-number, increasing the magnification, either by moving closer to the subject or using a lens of greater focal length, decreases the DOF; decreasing magnification increases DOF.








BY- Cricket