How to take pictures with a mobile phone that blurs the background?

In portrait photography, many people like portraits with a blurred background. So how are such photos taken? In fact, it is not difficult to take photos with this kind of background blur. The main thing is to grasp the relationship between aperture, focal length and shooting distance. Let’s take a look below.

(Portrait works with blurred background)

1. How to determine the depth of field

The concept of depth of field has been introduced in the previous chapter. When we shoot any When it comes to objects, we need to focus on them before shooting. Only when the focus is "real" can we trigger the shutter. Then, when the object is in focus, it is actually quite clear at a certain distance in front of the object and a certain distance from the object to the back. Generally speaking, we call this distance in the front and back clear range or The depth is called depth of field.

(Control of depth of field when shooting portraits)

In photography and portrait photography creation, we need to determine the depth of field according to the theme and intention of the shooting, for example, shooting travel souvenirs Not only do the photos need to be clear about the characters, but the flowers in front of the characters and the background behind them also need to be clearly recorded to tell the audience the feeling of visiting here. This requires shooting with depth of field. Another example is to shoot a table tennis player taking a shot. At the moment of the ball, the entire shooting scene may also include the audience behind the athletes. At this time, in order to highlight the people and actions of the subject, it is necessary to exclude all factors that interfere with the subject, and a shallower depth of field is required. Take the shot.

2. Three major methods to master depth of field and blur the background

Next we will talk about the three elements that affect depth of field and their application in portrait photography.

First, the larger the aperture value of the lens, the shallower (smaller) the depth of field. For example, the photographer uses a large aperture such as F1.8 to keep the characters within the clear range of the depth of field, while the background is outside the clear range of the depth of field. In this way, the background is completely blurred, effectively highlighting the characters in our picture. .

(A large aperture achieves a shallow depth of field and blurs the background)

Second, the longer the focal length of the lens, the shallower the depth of field. If two lenses with different focal lengths use the same aperture and are shot at the same distance from the subject, the lens with the longer focal length will take a photo with a shallower depth of field.

(The large aperture of a telephoto lens can blur the background very well)

In this portrait photography, the photographer used a telephoto lens to record a beautiful model , it can be clearly seen that the telephoto lens and large aperture can blur the background environment of the characters, thus completing the blurring of the background well, and thus highlighting the subject of the characters we photograph.

(Shorter shooting distance achieves shallow depth of field and blurs the background)

Thirdly, the closer the lens is to the subject, the shallower the depth of field is. If two lenses have the same focal length and the same aperture are set at the same time, in this case, the depth of field is related to the last factor, which is the shooting distance between the lens and the subject. We call it "shooting distance" for short. ". If the shooting distance is shorter, the photos taken will have a shallower depth of field; conversely, the depth of field will be larger.

In addition to using the three techniques we mentioned above to control the depth of field and blur the background, a professional portrait photographer should also pay attention to the selection of the background of the characters. Although objects outside the depth of field are blurred, the general outline and color of the object will affect our subject to a greater or lesser extent. Therefore, it is very important to choose a background that is clean and consistent with the subject of the photo. It is also an important criterion for measuring whether a portrait photographer is professional.

The following three techniques are shared to control the depth of field in portraits. I hope it will be helpful and inspiring to everyone when they encounter bottlenecks in shooting. In many cases, in order to obtain photos with blurred backgrounds and highlighted human subjects, these methods are often used in combination to achieve the most ideal effect.