Practical Artistry: Light & Exposure for Digital Photographers

52 Working with Aperture

Aperture and Depth of Field

Aperture and Depth of Field

As a photographer, it’s important to have a good gen-

eral sense of how aperture relates to depth of field. Add

to this a sense of where you should focus for maximum

depth of field, and you’ll have a great head start in us

-

in

g aperture creatively in your photos.

But the rubber meets the road, or the finger meets the

shutter release, when you are actually taking photos.

How can you get a sense in real time, while you are tak-

in

g photos, of the impact of your aperture choices (so

that you can adjust aperture as necessary)?

In Chapter 1, I explained that aperture, one of the three

components of an exposure, refers to the size of the

opening in the camera lens. Aperture plays a crucial

role, along with shutter speed and sensitivity, as one of

the three components of an exposure.

As I described in Chapter 1, the notation commonly

used for aperture is the f-stop, written f/

n.

n is called

the f-number, and corresponds to the diameter of the

opening in the lens. Unlike the other two exposure

components, you can’t use f-stops or f-numbers in a

direct arithmetic calculation to adjust exposures.

These two photos of a Dahlia taken from the same position in the same light

illustrate the impact of aperture on depth of field.

The photo on the left, taken with the lens stopped down all the way for ...