What is focusing, and which part of the distance is adjusted when the camera autofocuses

What is Focus? I'm too professional to say it, but simply focus on the object you want to photograph, that is, only the object you shoot is the clearest. Actually, you don't need to adjust anything, you only need a half-ampered shutter to focus (autofocus).

If you are doing it manually, rotate the focus ring on the lens until the object is clear.

The aperture controls the brightness and depth of field of the picture, and the focal length controls the distance of the subject (zooming in and out).

There is a focus point selection in the camera, and the autofocus generally only focuses on the focus point you choose, and nothing else

When the camera autofocuses, it adjusts the distance from the lens to the image plane (i.e., film or CCD) to make the image clear, and the aperture and focal length affect the depth of field. If the depth of field is small, it is necessary to focus precisely.

Turn the focus ring until the picture in the lens is the clearest.

The autofocus has nothing to do with the distance you are adjusting.

Autofocus. Gently press the shutter with your hand, not completely, and then the lens will autofocus, adjust the position of the lens, gently press the shutter many times, focus to the desired focus, and then press the shutter.

Manual focus. It is to slowly rotate the focus ring on the front of the lens with your hand and adjust it slowly, so that the focus point you want to change from blurry to clear, that is, to achieve focus.

The imaging quality of a DSLR camera is mainly based on the size of the lens aperture and the frame of the image sensor. That is, a lens with a large eye aperture, a full-frame sensor. Multi-point focus is mainly about the area of focus and the success rate of capturing the target. So a 51-point one is better than a 39-point one.

Phase focus. Phase focus literally means "phase detection autofocus". It should be pointed out that phase focus technology is very mature in the field of digital cameras, but it is still in its infancy in the field of smartphones.

The phase difference detection method is a common focusing scheme used in DSLR digital cameras, and it is also applied to the focusing system of mobile phone cameras. From the perspective of DSLR digital cameras, phase focus is applied to the dedicated sensor for autofocus installed in DSLR cameras. This scheme achieves high-speed focusing by detecting how much difference exists in the front and back directions of the focus point.

The above content reference: Encyclopedia - Focus.

The focus system of the camera generally selects the focus point according to the range focus, regional focus, and the part with the greatest contrast, and a good camera can adjust the focus area.

A camera, or camera, is a device that uses the principle of optical imaging to form an image and record it with a negative. The camera is an optical instrument used for photography, and the light reflected by the subject is focused through the camera lens and the shutter that controls the amount of light, and the subject forms a latent image on the photosensitive material in the camera obscura, which is processed to form a permanent image, which is called photography. After 1939 was the third stage of the development of the camera.

In the first half of this stage, that is, before the sixties of this century, the quality of black-and-white and color films was further improved, and the optical industry made new optical glasses containing rare elements, such as lanthanum, titanium, cadmium and other glasses. As a result, the aberration of the photographic lens is better corrected, so that the lens develops rapidly in the direction of large apertures and multiple focal lengths. As a result, a variety of photographic lenses such as zoom, emblem distance, catadioptric and wide-angle have emerged.

Single-layer coating of lenses is widely promoted. Cameras have mechanisms such as automatic counter reset, mirror auto-reset, semi-automatic, and fully automatic aperture retract. The quality and production of cameras began to develop rapidly.

It is believed that for professional photographers who like to play with the camera, focusing.

It is very simple to get started, but for anyone who is new to or has basically never touched a camera, the focus may be more digital camera.

As strange, so what does focusing mean? It means that the camera adjusts the focus distance, so let's take a look at the specific introduction.

Focusing is very simple for professional photographers, but for most beginners or people who have not been exposed to it, it is completely unfamiliar territory, so let's first look at what does focusing mean? The English scientific name of focus refers to the process of adjusting the focus distance of the camera, which enables the camera to image clearly. Guess the object.

Focus is also divided into manual focus and autofocus, so what is the interval between manual focus and autofocus? Artificial focus is achieved by manually rotating the lens trillion focus ring, while autofocus is the camera's use of infrared light.

After precise ranging such as ultrasound and aurora, the lens is automatically moved to achieve focus, but the focus point of the star is more arbitrary, so even with a highly autofocus lens, it is always necessary to set a little more manual focus mode.

In the focus mode, there are six types of AF, 51-point single-point focus, 11-point single-point focus, 9-point dynamic area focus, 21-point dynamic area focus, and 51-point dynamic area focus. Let's take a look at the specific introduction:

1.Auto-area focus, which checks all objects in focus and selects the nearest point to focus, which is suitable for focusing in snapshots;

Single-point focusing, which can choose the focusing position according to shooting needs, is suitable for high-precision focusing;

Single-point focusing, which can shorten the switching time of the focus under the same focus area and accuracy, is suitable for daily shooting;

Point dynamic area focusing, suitable for shooting uniform and slow moving objects;

Point dynamic area focusing, suitable for shooting irregular moving objects;

6.How to choose the focus mode, which is suitable for tracking and focusing on the photographed subject.

Bright liquid coke is very new to most non-specialists, so what does focusing mean? It is the camera to adjust the focus distance, which is a process that enables the camera to image clearly.

Cover pants such as pure sharp focus refers to the use of the camera to adjust the focus distance, the English scientific name is focus, usually digital cameras have a variety of macro focus methods, namely autofocus, manual focus and multiple focus methods. Focusing is also called light and focusing.

Focus refers to adjusting the focus distance when using the camera, and is divided into autofocus, manual focus, and multifocus.

The camera adjusts the focus means that the camera adjusts the focus on the person, so that the ** comes out very clearly.

Categories: Culture Senze Art >> Calligraphy and Painting.

Analysis: Focusing is an act that ensures a clear image is obtained. That is, after ruling out the problem of the camera itself, accurate focus can get a clear **. Focusing can generally be divided into two types: manual and automatic.

Focal length The distance between a point in a curved mirror or lens and its primary focal point. Curved mirrors are counted from their vertices, thin lenses are counted from their centers, and thick translucent round mirrors and lens groups are counted from the main plane on the side where their main focus is located.

The length of the focal length of a photographic lens determines the size of the angle of view and depth of field. The simple family collapse theory: the angle of view and depth of field of the long focal length lens are smaller, and the part of the scene can be shot at a long distance or at the same distance; Short focal length lenses, on the other hand, have a wider angle of view and depth of field, allowing them to shoot a wide range of objects at the same distance.

Photographic lenses are made into long focal length lenses, medium focal length lenses, standard lenses, wide-angle lenses, and ultra-wide-angle lenses (fisheye lenses) according to needs. For cameras with different formats, the parameters of the corresponding long, medium and short focal lengths are different because of the different frame sizes. In the case of 135 cameras, the general long focal length refers to a lens of more than 180mm, which is suitable for shooting wildlife, sports competitions, racing cars and other scenes that are not easy to approach, and is also used to shoot close-ups of scenes at a relatively short distance; The focal length of a mid-focus lens is generally 100 to 150mm, which is suitable for shooting portraits or portraits; Lenses with focal lengths between 45 and 60mm (120 cameras are generally 65 80mm) are used to be called standard lenses because their angle of view is closer to the angle of view of the human eye, and thus become the most commonly used lens; A lens with a focal length of less than 30mm is called a wide-angle lens, which can shoot a wide range of scenes at a short distance, such as in a room of 3 4m, where a group of about ten people can be photographed.

1. The nature of the picture is different between focusing and focusing.

Focusing is to adjust the distance of the picture, the shorter the focal length, the wider the angle of view, and the more things can be accommodated in the picture; Focusing is to adjust the clarity of the picture, and the closer the focus distance is to the actual distance of the photographed object, the clearer the picture.

2. The role of focusing is different from that of focusing.

The focus is related to the distance of the subject, and the focal distance of the lens can be adjusted between the closest point and the farthest point within the lens focus range, that is, infinity; The focal length is related to the angle of view of the picture, the longer the focal length, the narrower the angle of view, and the closer the picture looks.

3. The order of use of focus and focus is different.

The order of taking pictures is to adjust the focal length (zoom to get the right picture); Then focus and finally determine the ** amount (set the aperture, shutter, sensitivity, are all done together).

The focusing speed of a DSLR camera is related to the body, lens, ambient light, and subject.

1. The fuselage, how much is the focus point of the fuselage, and whether the focus point is a word or a cross. However, at present, there are not many focusing methods driven by the body, and they are basically not used. It just sends a drive signal, so it doesn't matter much.

2. Lens, this is the most important factor. The difference in focusing speed between different types of lenses is relatively large.

3. Ambient light, the darker the ambient light, the slower the focus. Scenes of the same color or line are also not easy to focus. When using the camera, the greater the difference between the last focus point and the point where it will be focused, the slower the focusing speed will be.

Generally, the camera is automatically positioned to the farthest point after it is turned on. Therefore, many friends set up the continuous focusing mode in practice, which is expensive to machine, but the focusing speed has also been improved.

4. The subject, if it is too flat and too light, is like a large flat wall, which is relatively clean and flat, and there is no task on it. At this time, it is relatively slow, mainly because there is no reference basis, and the camera will focus repeatedly.

It should be said that there are, different brands and models of machines have different structures, and their focusing speed is also different, some of the focusing driven by the fuselage motor is slower than that driven by the lens motor, and the combination of the same machine and lens is generally lower than when the light is good.

It's mainly related to the lens, first of all, look at the purpose of the lens and the focusing stroke, for example, the focusing speed of a macro lens is relatively slow, because its closest focusing distance is relatively small, and the focusing stroke is very long, so it will be slow.

And then there's the motor of the lens, and if the motor is fast, it's a little better, and if the lens doesn't have a motor, you have to rely on the body.

The focusing speed of a DSLR camera is related to the body and lens, the ambient light, and the subject, the focus point of the body, and whether the focus point is a line or a cross.

Whether the lens is micro motor or ultrasonic focus.

What is the maximum aperture of the lens.

Shoot the illuminance of the ambient light.

All of these factors can affect the focusing speed, but generally speaking, the more crosshair focus points, the faster the focusing speed.

The lens of an ultrasonic motor is faster than that of a regular micro motor.

The larger the maximum aperture of the lens, the faster the speed, and the darker the ambient light, the slower the focus.

Large areas of the same color or line are also not easy to focus.

It should be said that the biggest influence on the speed of focusing is the ambient light and the subject.

Distance sensor and focus motor!

The rules for selecting the focus point of the camera's focusing system are: single-point focus, dynamic area focus, automatic area focus, etc.

1. Single-point focusing

This option is suitable for situations where the subject is stationary or slow, and the position is relatively fixed, such as landscapes, still lifes, portraits, etc. In this option, we can specify a focus point that allows the camera to focus only at that position. This ensures that we shoot clearly and sharply, and we can freely control the composition and visual center of gravity of the picture.

2. Dynamic area focusing

This option is suitable for situations where the subject is moving rapidly or irregularly in the air, and the position is constantly changing, such as sports, animals, aircraft, etc. In this option, we can specify a primary focus point and have the camera automatically adjust the focus points in other vicinity of the hail to assist tracking based on the direction and speed of the subject's movement.

3. Auto area focusing

This option is suitable for situations where the number of subjects is large or widely distributed, and the location is uncertain or difficult, such as crowds, flowers, starry sky, etc. With this option, we can have the camera automatically select all available focus points and focus on the closest or most prominent subject in the frame.

Camera photography skills

One way to add a sense of motion to an image is to zoom in on the lens while shooting to keep the camera still. When panning places vertical motion in **, zooming creates a dynamic 3D effect. When you combine the zoom with the slow-sync flash, you get a very remarkable effect.

You've probably been told that to get a really sharp image, you need to keep the camera still while shooting, and I don't want to dispute that. But sometimes what you want is with a different result. You can add movement to your fight** by moving the camera while shooting.

To achieve this effect, you can pan, rotate, and even throw your camera.

Adjust the shutter speed to excessive** and you can get bright, burnt images. Use this technique if you're shooting colored objects, as it will give you an image on a bright, burnt background. If you're shooting in low ambient light and you want to illuminate the subject with a flash, this technique is your best bet.