Effectively control the depth of field

Camera depth of field: when the camera's lens is in focus on an object is clear, canvas prints for the position in the center of the lens from the same point in the plane of the vertical axis of the lens can be quite clear images in a film or a receiver, in the plane along the axis of the lens in front of and behind a range of points can also form a eyes can accept more clear image point, the distance of all objects in the front and rear of the plane is called the depth of field of the camera. Generally speaking, the depth of field is the clarity of the subject's background or foreground. Depth of field has an important impact on the visual effect of photos. By understanding its principle and mastering its rules, depth of field can be used as a creative element in photography activities and its imaging characteristics can be controlled to achieve a certain desired visual effect.

1. Use aperture to control depth of field

Aperture size is closely related to depth of field. The effect of adjusting the depth of field by aperture is obvious under the same shooting distance. When the depth of field needs to be reduced, the background should be blurred with a large aperture or even the absolute aperture of the lens, namely the maximum aperture: when the depth of field needs to be increased, canvas australia a small aperture or even the minimum aperture should be selected. Even in the same shooting distance, using the same focal length to shoot the same object, the effect of the small aperture on the depth of field is very obvious. If the aperture is selected at the same time, pay attention to the use of zoom lens to do the focal length and distance changes, the use of depth of field is more flexible and scientific.

2. Control the depth of field by using distance shooting

When shooting ordinary scenes, hanging aluminium prints the depth of field is mostly calculated in meters. For close-ups, the depth of field is often measured in centimeters: when using a macro lens or a portable digital camera in macro mode for close-ups, the depth of field is often measured in millimeters. The closer the camera is, the shorter the depth of field. If you want to shorten the depth of field again on the premise of using a telephoto lens and a large aperture, you should shorten the length of field without affecting the composition. If you still want to increase the depth of field by using a short focal length and a small aperture for macro close-up, you can increase the depth of field by slightly extending the distance back.

3. Use the distance between the subject and the background to control the depth of field

When the distance between the subject and the background is close, the effect of shallow depth of field is difficult to display: when the subject and the background are both in the infinite distance, even the long-focus lens with a large aperture is difficult to effectively blur the background. If possible, the camera should be as close to the subject as possible, while the subject should be as far away from the background as possible. In this way, the effect of blurting the background will be more obvious. Sometimes, the subject is at a close range and the background is at an infinite distance. In other words, shooting with a wide Angle lens and a large aperture can effectively blur the background.

4. Apply the principle that the background is deep in the foreground

In the practice of photography, photographers should make full use of the front and back depth of field according to the formation characteristics of the depth of field. Generally, they can make full use of the depth of field by selecting the focus. For the close-up of a half-profile figure, the focus should be placed on the eyes close to the lens. According to the principle that the depth of the background is greater than the depth of the foreground, when one eye is clear, the other eye will be relatively clear: if the focus is on the eye far away from the lens, the eye close to the lens is likely to appear blurry outside the depth of field, which is a waste of the depth of field. If there are four rows of photos before and after shooting, the focus is on the second row, and the first, third and fourth rows are relatively clear, which is to use all the depth of field.

5. Use "aperture first" and "depth of field ladder exposure".

Whether it's A SLR or A laptop, you can choose the aperture through manual mode "M" and aperture priority mode "A" to maximize the effect of aperture control depth of field. It should be noted that the "large aperture" is not a normal aperture like F5.6 or F4, including the absolute aperture of F2.8. In fact, when it comes to general shooting, the difference of depth of field between medium apertures is relatively small. In many cases, it is difficult to obtain obvious short depth of field if the aperture is not really large.

Depth of field is not the shorter the better, nor is it the longer the better. Sometimes the background needs to be just right, that is, the background can neither be so blurred that it is impossible to understand its specific connotation, nor so clear that it is the most appropriate to produce visual interference to the subject. Since DSLR cameras all shoot at the maximum aperture, there will be some difference between shooting and actual imaging as long as the aperture value is not the same. When using a conventional camera. The "depth of field prediction" button on the camera body is often used to check the depth of field effect. There is also a "depth of field prediction" button on the DSLR camera, and the actual shooting effect can be checked at any time. If necessary, panoramic canvas the aperture priority mode can be used to shoot several photos with different apertures on the premise that the composition and shooting distance remain the same for later selection.