What is depth of field - 上海419贵族宝贝-上海后花园1314-上海品茶网-阿拉爱上海

As for photography, many people will pursue the effect that the subject of the character is clear and the background is fuzzy, which is what we often call clear foreground and fuzzy background. However, this effect is usually easier to achieve on SLR, but it is quite difficult on mobile phones, and the reason for this involves the depth of field.

What is the depth of field

Depth of field is a description of the range of distance that can be clearly imaged in space. Usually, the blurring degree of the image in the photos taken by us within a certain distance is invisible to the naked eye, and we call this distance depth of field.

Benefits of depth of field

When we shoot some scenes, it is better to have a large depth of field, and sometimes it is better to have a shallow depth of field. For example, when we shoot landscape photos, we need a deep depth of field, while when we shoot portraits, we need to use a shallow depth of field.

The shallow depth of field can only highlight the main body, while the virtual background makes things more pure. Especially for some complex environments, the virtual background is more easily accepted by the naked eye.

How to obtain shallow depth of field

The depth of field is related to the aperture, focal length and object distance of the lens,

The larger the aperture, the smaller the aperture value, and the smaller the depth of field;
The smaller the aperture, the greater the aperture value, the greater the depth of field;
The longer the focal length of the lens, the smaller the depth of field;
The shorter the focal length, the greater the depth of field;
The farther the distance, the greater the depth of field;
The closer the distance, the smaller the depth of field

From this, we can know that if you want to shoot a shallow depth of field effect with your mobile phone, you must use a large aperture, a long focal length, and be close to the shooting object. However, for mobile phones, the aperture and focal length are fixed. The only thing we can change is whether we are close to the object. The closer we are to the object, the easier it is to get a clear theme and a blurred background. This is why it is easier to take this kind of background blurring effect when shooting small objects on the desktop with mobile phones. However, when shooting portraits, we can't get the effect of virtualization because the shooting distance becomes far away.

But why is it so easy for an SLR camera to take a virtual effect? This is mainly because the actual focal length of the SLR is longer than that of the phone lens. The phone lens is limited by the body, so the whole lens is only a little thick, and the sensor is only a little big. So we can imagine that the actual focal length of the SLR is very short. Compared with the SLR, it is too far away. Don't think that the phone can surpass the SLR.