For many of us, Depth of Field is not a new term at all. And would be a day-to-day process while capturing the images. While some of the photographers use this term very often. There are a few others who would be new to this. Well, it’s important to know about the depth of the field, before you could apply the same. So, let’s see here what is Depth of Field in Photography? How to Apply? And the factors affecting the Depth of Field.
What is Depth of Field?
Depth of field is the range of subject distance within which the subjects from nearest to the furthest away from the focus plane are imaged with acceptable sharpness. Thus, a focused area as a sharp portion in an image is called depth of field. In other words, the Depth of field is the amount of your photograph that appears sharp from front to back. It is also called DoF in common.
The frame can be divided into three portions. They are Foreground, Mid-ground, and Background, with respect to the camera angle and position.
- The foreground is the area or portion of the frame that comes in front of the camera.
- Mid-ground is the area or portion of the frame that comes just behind the foreground.
- The background is the area or the portion back of the mid-ground or the back portion of the frame.
Types of Depth of Field
By now, it might be clear that the DoF refers to the range of distance that appears acceptably sharp. As per the focus area or portion we want to have in the frame, the Depth of field can be categorized as two types.
- Large or Wide Depth of Field
- Shallow or Narrow Depth of Field
Shallow Depth of Field
Shallow depth of field indicates that only part of a scene is in sharp focus. It is a powerful tool for making great pictures by drawing attention to specific aspects of a picture.
Shallow or narrow DoF has a very small area that is in sharp focus, i.e. at least one of the ground is in the focused plane while the other portions get blur.
If the focus is on the subject in mid-ground and the foreground, as well as background, remains out of focus or blurry as per the placement of the subject, then the DOF is said to be Shallow Depth of Field.
A smaller f-stop number or large aperture opening gives a shallow DoF.
Large Depth of Field
When subjects both near and far are relatively crisp and sharp, we say the image has a wide or large DoF. In such cases, the foreground, mid-ground, and the background all remain sharp and focussed. Thus providing a larger DoF.
High f-stops in the range of f/16 or f/22, which helps keep subjects in both the foreground and background in focus.
What are the factors that affect the Depth of Field?
While taking an image, the subject should be in focus and sharp, thus the DoF is so important to decide the area of focus on the frame. The depth of field mainly depends on the three factors, they are
- Aperture
- Focal Length
- Distance
How Aperture Affects the Depth of Field?
We have often come across several images where the subject is in focus and the entire background is a blur. This effect is caused by the aperture. When the size of the aperture is large it creates more blur or out of focus background with a shallow or small area in depth of field. If the aperture size is smaller it creates a large or deep DoF.
So, the large aperture size or the shallow depth of field will be suitable like in portrait photography. Since here the subject is to be in focus and sharp. Whereas the background will be completely blurred or out of focus. When you require the entire frame is to focus, the smaller aperture size with a large depth of field will be suitable. For instance, in landscape photography where more areas should be in focus and sharp.
So, the large aperture size or the shallow depth of field will be suitable like in portrait photography. Since here the subject is to be in focus and sharp.
When the aperture size is large it produces a shallow depth of field, and if the aperture size is small it creates a large depth of field. In other words, the smaller f/number gives a shallow DoF and larger f/number gives a large DoF.
How Focal Length Affects the Depth of Field?
The depth of field depends on the focal length also, when the focal length is long, we will get shallow depth of field when aperture, shutter speed, and ISO if fixed. When the focal length is short the depth of field will be large when aperture, shutter speed, and ISO are constant. The wide-angle of view gives a large DoF and narrow-angle of view gives a shallow depth of field.
How Distance Affects the Depth of Field?
When the focal distance between the camera and subject changes with a fixed aperture, shutter speed, ISO, and also focal length. With fixed focal length when the distance between the subject and the camera changes, if the distance is close to the subject it gives the shallow depth of field, and if the distance is long between the subject and the camera the large depth of field will be obtained.
According to this, before taking a picture the placement of the subject and the distance between the subject and camera should be made clear to get the required image either with shallow depth of field or large depth of field.
Depth of Field Tips and Tricks
Firstly, imagine the frame and then frame it. According to what DoF is required, adjust the distance between the camera and subject, set the proper aperture, and respective focal length. Remember, that the sensor-size has also an effect on the DoF. For example:
Mostly in portraits, the subject is more important than the background. So to make the portraits more attractive and to make the subject to separate from the surrounding, shallow depth of field is required. As a result, the large aperture size is required like f/2.8, f/2, f/1.4.
In landscape photography, it requires detail as possible from foreground to background. To achieve more focus, the maximum depth of field should be attained. Hence, selecting the large f-numbers or smaller apertures like f/8, f/11, f/16 or even f/22, will make it possible to bring a wide depth of field.
As we know that the larger aperture creates a shallow depth of field and the smaller aperture provides a large DoF. But, on some occasions, we may need a not too shallow or large DoF. In such situations the f/5.6, f/8 will be more worth making a moderate depth of field.
