Practice of Depth of Field

The aim of these photos is to compare the difference between the sizes of aperture and the relationship between aperture and depth of field.  I used tripod in order to keep the camera in a same position.  I shoot some objects on my desk and adjust the aperture from F4 to F20. 

1. 

2. 

In conclusion:

The lower the f/stop—the larger the opening in the lens—the less depth of field—the blurrier the background.

     The higher the f/stop—the smaller the opening in the lens—the greater the depth of field—the      sharper the background.