How to take clear photos

Beginners know that to take a clear photo, they generally need to: Use a high-speed shutter to reduce the aperture from the largest aperture to four levels; there must be a lot of light on the subject, the object to be taken should remain static, the tripod should be placed stable, and the action should be light when the shutter is pressed. However, even if you pay attention to this, many experienced photographers still feel that the photos are not clear enough. Some photographers also believe that the most difficult thing to grasp when taking dynamic photos is the definition of the photos. So what are the causes of Image Blur?

British photographer D Lynch pointed out: "One of the most interesting characteristics of photography is that it is a combination of multiple factors, one factor always affects another. In terms of image clarity, the choice of the exposure combination can affect the degree of elimination. When we talk about image clarity, many photographers first think about the focus issue. However, Lynch believes: "The reason why the photos are unclear is that apart from focusing on this factor, there are a series of other factors. Such as the movement of the subject, the vibration of the camera, the contamination of the lens, the lack of depth of field, excessive exposure, light leakage, excessive development, film or the moisture on the lens, and so on.

Specifically, Image Blur is caused by the following factors:

First, because the shutter speed is too slow during the shooting of the subject, the image virtual motion is caused. The faster the motion, the slower the shutter speed, and the more blurred the image. American photographer Kepler once introduced how to identify whether motion-caused Image Blur: "In a photo, if some scenes are blurred, especially some parts with a certain angle, it seems more obvious, then, focusing is not the main reason, but the result of motion. If only the subject is blurred, and the subject is active and shaken (such as a tree or flower swinging in the wild) or moving objects, then this fuzzy phenomenon is caused by the subject movement. Kepler warned photographers: "Don't think that the speed of 1/125 seconds is enough to catch the animation as described in some tables, unless you use a high-speed flashlight, it is impossible to make the animation as clear as a static object. That is to say, I/O 1000 seconds to take a picture of a running football player. In the enlarged picture, the picture is not as clear as the picture when the player is standing ."

Of course, if you use a shutter speed that is fast enough, you can still take a clear picture of any animation (at this time, the photographer's response is also quite fast ). The key here is to pay attention to the angle between the tracker and the camera. For example, you want to take a picture of a person running 5 meters away. For example, the speed of a person running is 3 meters/second, and the direction is the line of sight of the photographer. (that is, the direction of the camera) to a 90 o angle, then, using a 50mm lens, you must use a shutter speed of 1/3500 seconds to take. In this way, the Blur range of the image displayed on the photo (acceptable degree of ambiguity) will be about 03mm mm, equivalent to the standard used in the depth-of-field table of the 35mm single-lens reflective camera. However, most cameras do not have such a fast shutter speed. The remedy is to reduce the angle between your sight and the shooting object to 30 ., In this way, you only need to use the shutter shot for 1/1750 seconds to achieve the same clear effect. For example, you can reduce the angle between the sight and the shooting object to 10 ., You only need to use the shutter for 1/500 seconds. Of course, you must take into account other key points for clear photos at the same time.

D. Lynch summarized three things that must be paid attention to when taking clear motion pictures: first, the motion speed is not too fast; second, if the motion speed is very fast, do not make the motion a horizontal motion in front of the camera. If the motion is fast horizontal, use the fastest shutter speed and the shooting distance should be as far as possible. Lynch believes that the third possible use is the least, because the images appearing on the film may be too small; the second may produce clear images and be dynamic; first, there is probably no problem to achieve good results.

The second reason for blurred images is that the focus is not accurate, or the subject is out of focus. If the camera is not properly focused, it will blur the shooting scene, and even the entire picture is not clearly located. There is no clear line between the parts of the subject, and make the four sides of the glare area virtual.

In the following situations, the focus is often false:

1. Due to carelessness and haste, the focus is inaccurate or not adjusted. It is not difficult to overcome this shortcoming as experience increases.

2. Inaccurate focus due to visual impairment. For photographers with poor eyesight, it is best to install a vision adjustment lens on the viewfinder.

3. Improper use of auto-focus cameras. Generally, the automatic focus of these cameras is aimed at the center area of the screen. If you take a picture of two people shaking hands, the focus usually goes from the middle of the two to the distant background, the result subject is not clear. The solution is to align the auto focus area of the viewfinder with the shooting object, or use the auto focus record lock on the camera.

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Some people even think that the auto-focus camera is unreliable, especially those which cannot be replaced.

Auto Focus pocket camera. According to information from the camera design, almost no camera can focus automatically. They can only focus in the area; generally, the autofocus system used by the mirror shutter camera is divided into passive and active. The basic principle of the Passive auto-focus system is to compare the phase of the object to be taken or analyze its contrast. The active auto-focus system emits a bunch of infrared rays from the camera before exposure, and then reflects back when an object is encountered, then the camera reads the video and controls the movement of the camera accordingly. In the early days, the "Auto Focus" mirror asked the shutter camera, most of which had four focal points. In addition to the wide-angle lenses commonly used by these cameras, the depth of field was originally large, so it could basically get enough clarity. However, it is only luck to focus the camera precisely on the plane of the subject. In most cases, focus can only be within the depth of field. A newer type of mirror shutter camera usually has more than four (some have more than eight) focal points, which makes it more likely to achieve better image clarity. However, if you want to achieve extremely sharp clarity at any time, you may still be disappointed.

The third cause of blurred images is that the camera vibrates due to unstable grip during shooting. As a result, even the static body is blurred. Generally, the trembling speed of the hand is about 5mm per second, and the frequency is about 20 cycles per second. The shift range is 0.25mm. If the hand is trembling, the roll will also move around, when the shutter is used for 1/250 seconds, the moving range is only 0.02mm, which is not a problem yet. However, if the shutter is used for 1/125 seconds, the moving range also doubles, which affects the photo definition. Therefore, practicing a camera or using a tripod is an important factor in taking clear photos.

In addition, some people think that the airflow is also a factor that affects the photo definition. If the image is shot through the airflow, the image may be unclear. In this case, try to avoid it. Atmospheric smog also causes a lack of contrast in the photo. A photo with a low contrast may also give you a sense of being in arrears. On the other hand, a high-contrast photo will give people a clearer impression when the focus is slightly false. Therefore, the contrast effect is slightly improved, and the image clarity can also be improved visually.

According to someone's analysis, another factor that affects the degree of clarity is the film. This does not refer to the effect of particles or the degree of photosensitive film, but to whether the film remains straight and motionless During the exposure. If the camera depth is small, the film is slightly curved, and the image in the photo will appear blurred. Studies have shown that if 35mm film has been placed in a tape box for more than an hour, and the film is quickly rolled and exposed, the film is most likely to bend. If you can roll the film up to ten times before exposure, the film will not bend. Of course, if the time permits, it is best to roll the film and start shooting after a period of time, the film will be more straight. On the other hand, it is also important to keep the film static during exposure. Do not place your thumb on the wrench to prevent the finger from moving the film. Generally, the film usually rebound slightly after being pulled. When you press the shutter, the photo will become unclear. This is why the last few photos taken with an automatic slice camera are not as clear as the first one.