Aperture

F2.8 Aperture

F16 Aperture

1.  Our pupils closely relate to aperture because they dilate to let in more or less light.

2.  The smaller the Aperture the bigger the opening, the higher the Aperture the smaller the opening.

3.  Depth of Field is how much of the background is sharp and in focus.  The larger the Aperture the thinner the Depth of Field.  The smaller the Aperture the larger the Depth of Field.