Photography Depth of Field Explained

In my almost twenty years of teaching photography at universities, I have learned that depth of field is the most difficult area for students. While beginning students can usually work well with their cameras in manual mode, which allows them to choose apertures and shutter speeds for their images, many of my students overlook the value of creating images with a narrow area of focus. This is a valuable tool that can be used to create striking images.

This is probably because they don’t get out enough to explore the possibilities. They spot something interesting in the distance, and they often just take the shot at that point without looking further.

What is a depth of field (or DoF)? It’s simply the term we use for the area of a photograph that is in acceptable focus between the closest point to the camera and the farthest point. This concept is interesting because it can vary based on the settings and choices made.

What creates different ranges of focus?

1. Size of the aperture.

Large aperture openings, such as f two and f 2.8, will offer the most focus. As the opening gets smaller, smaller apertures such as f 11 or f 16 will produce a greater depth of field.

2. Lens type. Lens type.

Wide-angle lenses are more likely to offer a wider range of focus than telephoto lenses. This is true for zoom lenses as well. If you set your lens to a wider angle, such as 35mm, the depth of field will be greater than if it was set to 100mm.

3. Focal distance.

It can have an impact on how narrow or wide your focus is. A focus point that is less than one meter away from the camera will result in a shallower depth-of-field.

Therefore, an aperture of f2.8 that allows you to focus on a subject within a meter of the camera will result in a narrower field of focus than one with a smaller aperture (f 8, 11, 16, or so). Because the camera is focused close to the subject, they will have a shallow DoF.

As one gets closer to objects, the DoF will likely become smaller. Why is this so important? It is obvious that a focus draws more attention to a subject than one that is not. A shallow focus can direct the viewer to the most important parts of the image. A shallow DoF that limits the focus to the subject and reduces distractions would be a good option to capture a portrait with a background that is distracting.