Digital Photography—Taming the Three-Headed Exposure Monster, Part 4

Part 3 of this five-part series presented information and tips about aperture, the third head of the three-headed exposure monster.

As if your digital photographer’s head was spinning already, aperture also has a direct connection to depth of field, which is what this Part 4 explains. Remember, depth of field simply represents how much of the depth of your picture appears to be in focus. Large depth of field means that objects both close to and far from the camera will seem to be in focus. Generally, you want many of your vacation and landscape pictures to have plenty of depth of field. Shallow depth of field means that a much smaller space in your picture is in focus. This could be a few feet or only inches. This would be appropriate if you are creating a portrait; you want the subject in focus, but not the background. Shallow depth of field is also a good technique for close-up nature photography, such as flowers, insects, birds, etc.

You can control the depth of field by setting various apertures (or f-stops), which in turn provides you with many opportunities to shoot more interesting digital photos. The formula is quite easy:

The smaller the aperture opening (which are the bigger f-stop numbers: f/22, f/16, etc.), the more depth of field.

The larger the aperture opening (which are the smaller f-stop numbers: f/2.8/ f/4, etc.), the less depth of field.

The best way to learn the relationship between shutter speed and aperture and aperture and depth of field, and how to use them, is plenty of practice.

Take your camera outside and determine the shutter speed and aperture for a properly exposed photo, and then shoot a few. Then, change both the settings to another combination that you think will also properly expose your digital picture; and compare the two sets. You can also purposely change just the shutter speed or aperture one or more stops to see how overexposed your pictures look.

Use another practice session to practice and test the relationship between aperture and depth of field. Shoot at various f-stops, as explained above, to see the effect on your digital photos.

Part 5 of this series will take the shutter speed and aperture relationship one step farther by revealing how to use the aperture priority mode and shutter priority mode to help you improve your digital photography.