How can I take a clear picture with a blurred background?

This is a typical photo with a shallow depth of field. To capture this effect, we should pay attention to the following three points:

1. Try not to take this photo with a fully automatic (stupid) camera, but use a camera with manual function.

2. When taking this photo, you must use a telephoto lens (including a zoom lens) with a long focal length, which is equivalent to 135mm of a 35mm camera.

3. Be sure to use a large aperture.

In addition to adjusting the exposure, the most important thing is to control the size of the "depth of field" of the picture. The so-called "depth of field" means that focusing makes the image clear, and the area within a certain distance before and after the focal length can be clearly displayed. This range is called depth of field. The longer the depth of field, the larger the range that can be clearly presented. On the contrary, the smaller the depth of field, the more blurred the foreground or background, which is a hazy phenomenon caused by poor focus. From the optical theory, under the focal length of the lens, only the plane at the object distance can be clearly shown, and the scenery outside this plane will be blurred.

Image depth of field has three factors:

1, the depth of field is inversely proportional to the length of the focal length, in other words, the longer the focal length of the lens, the shorter the depth of field.

2. The depth of field is directly proportional to the shooting distance of the scene. The closer the camera is to the scene, the shorter the depth of field.

3. The depth of field is proportional to the aperture series.

If it is inconvenient to keep the focal length of the lens and the shooting distance of the object, the larger the aperture, the shorter the depth of field. That is to say, when the aperture changes from f/111→ f/8 → f/5.6 → f/4, the depth of field becomes shorter and shorter, and the scenes outside the depth of field become more blurred. This hazy beauty is different from the blur caused by camera vibration. Full of elegant and soft luster, like rendered colored ink, it lightens the tone, can create a considerable atmosphere, has a sense of transparency away from the theme of depth of field, and has the characteristics of setting off the main body. Therefore, it is often used in portrait photography, and the background of the model is blurred, which makes people focus on the beautiful model. At the same time, because of the use of large aperture, there can be more light. In order to improve the shutter speed, prevent the camera from shaking, and make the image sharper and clearer, if you want to capture the environment and atmosphere at that time without the help of a tripod under the dim light source, or you can't use a slow shutter, you use a place with a large aperture, which destroys the atmosphere of the picture. Therefore, the large aperture lens has always been one of the equipment used by film friends.

If the aperture is smaller, from f/5.6 → f/8 → f/1→ f/16 → f/22 ..., the range of depth of field will be larger, the description of the scene will be more realistic and full of authenticity, and the picture quality will be clearer and Ming Rui than that of a large aperture. Moreover, due to the range of depth of field, In addition, the small aperture can reduce the aberration of poor image connection or poor light transmission of the lens, and obtain high-quality works. There is also a small aperture, which can reduce the shutter speed and create a sense of flow through a slow shutter.

For professional digital cameras, it is generally possible to manually control the aperture and shutter speed of the camera, but for commercial and household digital cameras, because the camera automatically controls the aperture and shutter speed, it is not necessary to control it by itself. ?

Simply put, it is long focal length+large aperture+precise focusing. The longer the focal length of the lens, the smaller (shallow) the depth of field; The larger the aperture, the smaller (shallow) the depth of field. Reasonable use of the two can produce the effect of clear subject and blurred background, which is a photography skill that highlights the subject (theme).

You can try it according to the above introduction, or you can start with the focal length of 100mm, gradually increase the focal length under the same large aperture and the same theme, and take more photos to see how the effect is. The longer the focal length, the better the effect of blurring the background. Of course, there is another one that is particularly important. To master the shutter speed, we should use a higher shutter speed,1125 seconds for ordinary cameras and 1/250 seconds for SLR cameras. The longer the focal length, the faster the shutter speed should be. If the shutter speed is slow, the photos taken may be all blurred.