Exploring Depth of Field
Unleash Your Creativity

With the proper understanding of Depth of Field You can exercise tremandous control over the look and visual impact of your images. But Depth of Field (DOF) is one of the most important but least understood aspects of photography, especially by beginners. Even when reduced to it's most basic terms, the relationship between aperture and DOF can be confusing at best.

On the bright side, with practice and perserverance the relationship between DOF and Aperture will become apparent to you. Unfortunately there is more to understanding Depth of Field than just adjusting the aperture!

What is Depth of Field?

It is the zone, or range of distances, within a scene, in front of and behind your main point of focus, that will record as sharp. It is one of the most creative and profound effects available to photographers.

The first thing a beginning photographer learns about DOF is that it is controlled by Aperture. The larger the aperture (f/2.8) the shorter the DOF. And the smaller the aperture (f/22) the longer the DOF.

But there is more to Depth of Field than just the aperture. It is also effected by how close the subject appears in your photograph. The closer you are to the subject, or the closer you make the subject appear by zooming with a telephoto lens, the smaller the DOF becomes.

An Easy Exercise

Sound confusing? If this is your first attempt to understand Depth of Field, don't worry! Get your camera, go outside and take some pictures of the same subject, at the same distance, but change the aperture with every shot! Start at f/22 and work down. You will notice as the aperture gets larger (smaller f numbers) the zone of acceptable focus in front of and behind your subject becomes smaller and smaller!

Now set your aperture to f/8 and take a picture of your subject at a distance of about 20 feet. This time, instead of changing the aperture, move closer to the subject, re-focus and take another picture. Repeat the process several times. You will notice that as you move closer and closer to the subject, the zone of acceptable focus (DOF) becomes smaller and smaller!

These are techniques commonly used by Portrait Photographers to make their subject stand out from the background and remove unsightly distractions by rendering them out of focus.

Increasing Depth of Field

This can also be accomplished by using aperture and distance. Imagine you are about to photograph two horses, one fairly close to you, the other farther away and you want them both in focus. If you shoot at a wide aperture you'll probibly get a great shot of one hores but the other may not be in acceptable focus.

You could improve the situation by closing down the aperture a few stops. But the most effective way to solve the problem would to move farther away from the first horse or zoom out to a wider angle. Not only will you capture more of the background, but more of it will be in acceptable focus!

Hyperfocal Distance

Hyperfocal what? Hyperfocal Distance is the point of focus that will give you the greatest range of acceptable sharpness from a point near your camera to infinity. Older lenses used to have a hyperfocal scale right on the lens barrel.

First you would line up the infinity mark with the aperture(f/22) you wanted to use on the left side of the scale. Then look at the corresponding aperture(f/22) on the right side of the scale to see how close your acceptable sharpness would be to you. The mark in the middle would indicate the hyperfocal distance. Where you wanted to focus to achieve the maximum range of acceptable focus.

Our modern lenses no longer incorporate this scale on the lens barrel. Maybe the Engineers feel that this information is no longer useful to today's photographer, but it is a shame that it is gone.

Finding the Hyperfocal Distance Today

There is a formula for finding the hyperfocal distance of all of your lenses. But if your not really into slide rules (for all of you who grew up with pocket calculators, this is what we used before calculators were invented) it's a lot of work!

Then there is the "That Looks Right" formula. Focus about 1/3 of the way into the scene. Or you could use the Depth of Field Preview button on your camera to check the range of acceptable sharpness. The problem here is that if you focus past the Hyperfocal Distance you are cheating yurself out of depth of field. And if you focus in front of the Hyperfocal Distance, your depth of field may not reach all of the way out to infinity!

The Answer

So what if you don't want to go broke hunting through camera shops buying old manual lenses and calculator batteries? Vivid Light Photography has compiled a great chart on Hyperfocal Distances. Click here to download their very handy chart. After you've done that, be sure to visit Vivid Light Photography Magazine and read some of their great articles on all aspects of photography.

Next time you are out making photographs, try experimenting with Hyperfocal Distance. The quality and visual impact of your landscape images may really surprise you! But remember the key to achieving great landscape images is to use a tripod and cable release.

Return toTechnical Info

Return to Quick Tips

Return from Depth of Field to Home Page