Chapter 3: APERTURE AND DEPTH OF FIELD
Along with the other two points on the exposure triangle—shutter speed and ISO—aperture is a way of managing the amount of light coming into your camera. Aperture is how much light hits your sensor (or film) via the opening in your lens.
If we look at the exposure triangle again (see Figure 3-1), we see that aperture also affects depth of field (DOF). Depth of field refers to how in or out of focus the foreground and background are in your image.
As you change your aperture to let in more or less light, you are also changing the depth of field. Be sure to keep that in mind when you are choosing your aperture because aperture impacts more than just your exposure. In other words, just like changing shutter speed affects motion blur and changing ISO affects noise, changing aperture also affects how your image looks via depth of field.
As we move through this chapter, we will tackle what aperture really means, how it is expressed, and how it affects your exposure. After that, we’ll explore the way aperture affects your depth of field.
FIGURE 3-1 In the exposure triangle, aperture controls depth of field.
WHAT APERTURE OR F/STOP MEANS
The terms aperture and f/stop are interchangeable. The aperture of a lens is essentially the opening ...
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