How Does Aperture Affect Depth of Field?
Learning about aperture and depth of field will be a heavy focus for your early filmmaking days! While you get to know your camera and how to adjust simple elements to create extreme changes to the shots that you capture. As an aspiring filmmaker, it’s important for you to understand how depth of field can be impacted by simple adjustments to your camera aperture. As well as various other elements. Unfortunately, understanding depth of field, shutter speed, the exposure triangle and aperture isn’t always straightforward and easy to understand. For example, “How does aperture affect depth of field?”
What is Depth of Field?
The depth of field represents the area of an image that is in focus. Thus, the “depth of field” is the degree of depth that is located within the field of acceptable focus.
The depth of field, DOF, is best described as the area from front to back that is in acceptable focus comparative to the total plane of focus.
So what’s the plane of focus? It’s the imaginary plane in which objects are set and the elements on the plane are in critical focus.
What is Aperture?
Aperture is the tiny hole in the camera lens through which light will pass through as it enters the camera to ultimately pass over the sensor. Aperture is measured, generally, in f-stops which ultimately represent the exposure of the camera.
Cameras with lower f/stops, or lower aperture, expose more light to the camera. As they represent larger apertures or holes that are allowing light into the camera. A higher f/stop means the camera has a smaller hole for light to pass through to the sensor which creates less exposure.
How Aperture Impacts Depth of Field (DOF)
As we seek to answer the question, “How does aperture affect depth of field?” we must carefully examine the impact of aperture and exposure on depth of field.
Remember, increasing the aperture, or f/stop, is equivalent to reducing the hole in the camera so that less light can pass through.
Thus, increasing the aperture also results in the plane of focus being increased. Each time the aperture is increased, the area in focus that stands in front and behind the original PoF is deepened. Which results in more of an image being included within that area.
For Example
If you’re focusing on an individual in the plane of focus, increasing your aperture will result in equal increases in the depth of field.
In layman’s terms? As you increase your aperture, you’ll also have more in front of and behind your subject in focus because you increased your depth of field.
Likewise, if you lower your f-stops, or decrease your aperture. You’ll also reduce your depth of field. Resulting in a loss of visibility of what’s in front of, or behind, your subject. This is how aperture impacts depth of field for your production.