What is Depth Of Field?
The terms ‘depth of field’, ‘bokeh’, ‘aperture’, and ‘f-stop’ get thrown around a lot in the photography world. But what does it all mean, and how can you bring you photos to the next level by understanding a little more about this subject? Let’s begin with finding out what depth of field is all about.
For those new to the world of photography, or for those who are looking to take their images to the next level, an understanding of depth of field is essential. So what, exactly, is depth of field (DoF)? Depth of field refers to the distance, from closest to farthest, in a photo that appears extremely sharp or in focus.
How to Control DoF
The main factor which controls the DoF is the aperture. When the f-stop number is small (f/1.4 or f/2.8) the DoF will be shallow and only a small range of the subject will be in focus, but a larger amount of light will be reaching the sensor. When the f-stop number is large (f/11 or f/16) the DoF will be larger and more of the image will be in focus, and a much smaller amount of light will be reaching the sensor. Keep in mind, there are a number of other factors that affect the DoF as well. These include the focal length of the lens, distance from the subject to the lens, along with sensor size. This f-stop is simply the first, and arguably the most important, factor.
For those just beginning to venture out of Auto Mode on their camera, using the Aperture Priority Mode will allow you to manually adjust the aperture while the camera automatically determines the rest of the settings.
When to use a Shallow vs. a Large DoF
As a photographer (and a visual learner), I find that it is easiest to get a point across using image examples.
First, I’ll show what a shallow DoF looks like. A shallow/narrow DoF is responsible for the bokeh effect, as seen here, where the subject is in sharp focus while the background turns into out-of-focus points of light.
A shallow depth of field can be used to draw the views eye to a particular point in the image. Here the camera is close to the subject, and the aperture is set to f/2.8. You can see that the very narrow depth of field draws your eye to the blue and neon green colored pencils.
In this example we have a much wider DoF, allowing most of the path and trees in the image to be in focus. I find that with most landscape photography, shooting with a wider depth of field will produce an image that is more pleasing to the eye.
Learning how to make the most of your camera and lenses, by controlling the depth of field, is a key aspect of taking your photography to the next level. It’s always best to take your camera out and experiment with different techniques to find what works best for you.