Professional knowledge of photography

Photography expertise, in daily life, we often encounter all kinds of beautiful scenery, and then record these scenery with mobile phones or cameras. But the beautiful scenery is not beautiful. Let's share some professional knowledge of photography.

Professional knowledge of photography 1 1, focal length

When you understand the focal length, you don't have to look at those official terms. Few people can understand it. You only need to understand the focal length as: how far or how wide a lens can shoot. The smaller the number, the shorter the focal length and the wider the viewing angle; The larger the number, the longer the focal length and the narrower the viewing angle.

For example, a lens with a focal length of 300mm has a viewing angle of only 8; And an 8mm super wide-angle lens has a viewing angle of 180. Usually, lenses with focal length below 24mm are suitable for shooting landscape themes; Lenses with focal lengths of 50mm and 85mm are suitable for taking portraits.

Second, the aperture

Aperture is a light hole formed by overlapping small leaves inside the lens, and the light receiving amount of the image sensor can be adjusted according to its opening and closing degree. For example, when the aperture is open, a lot of light passes through; If the aperture is reduced, the luminous flux will be limited. Aperture is generally represented by "F", and the number after F represents the size of the aperture. The larger the number behind, the smaller the aperture; The smaller the number, the larger the aperture.

In addition, the aperture also affects the depth of field of the photo. The larger the aperture, the shallower the depth of field, which means that the background of the photo is blurred. The smaller the aperture, the deeper the depth of field, which means the clearer the background of the photo.

On the left is a large aperture (f/ 1. 4); On the right is the small aperture (f/ 16).

Third, the depth of field

The explanation of the technical term depth of field is that when the front edge of the camera lens is clearly imaged, it can obtain the range of the distance between the subject and the background, which is actually the clarity between the subject and the background.

In addition, there are three factors that determine the depth of field, namely: aperture size, shooting distance and lens focal length. Next, let's talk about how these three elements affect the depth of field.

① pore size

The larger the aperture, the shallower the depth of field, the smaller the aperture and the deeper the depth of field.

② shooting distance.

The closer the subject is to the lens, the shallower the depth of field; The farther the subject is from the lens, the deeper the depth of field. ③ the length of focal length

The longer the focal length, the shallower the depth of field, the shorter the focal length and the deeper the depth of field.

Fourth, the shutter speed

Simply put, the shutter speed indicates the length of time that light shines on the image sensor. Generally speaking, the aperture size determines how much light can enter the camera at the same time: the shutter speed determines the exposure time of the sensor. Shutter speed: the smaller the denominator, the slower the shutter; The larger the denominator, the faster the shutter. For example, the shutter speed is 1/3 seconds, that is, the exposure is one third of a second. This exposure time is very long. The shutter speed is 1/200 seconds, which is one hundredth of a second of exposure. This exposure time is very short.

Shooting the same object with different shutter speeds will produce different effects. For example, the waterfall photo below. The photos taken by high-speed shutter are full of vitality, while the photos taken by low-speed shutter fully show the flowing feeling of water and create a quiet atmosphere.

Fifth, focus

Focusing is the process of changing the distance and the position of the distance through the camera focusing system, so that the photographed object can be imaged clearly. In order to help you master focusing skillfully, the following will explain focusing knowledge for you one by one.

① Single autofocus: This focusing mode is suitable for shooting still objects. When the lens is aimed at the subject and the shutter is pressed for half a time, the camera will focus once.

Single servo mode is suitable for shooting still subjects.

② Continuous autofocus: Continuous autofocus means that the camera presses the shutter half-way, and after focusing, it will lock the target or lock the focus area. Once the focal length of the target and the camera changes, the camera will automatically refocus. Continuous autofocus is most suitable for shooting moving targets, such as sports photography, wildlife photography and automobile advertisements.

Continuous autofocus is suitable for shooting moving subjects.

③ Intelligent autofocus: This mode combines single focus and continuous focus. After half pressing the shutter, the subject at the focus can be locked for single focusing, and when the subject is moving, it can also be switched to continuous autofocus for tracking shooting, which is suitable for shooting objects with random motion mode.

Intelligent autofocus is a combination of single focus and continuous focus.

(4) Manual focusing: Manual focusing is a focusing method that adjusts the camera lens by manually turning the focusing ring to make the photographed photos clear. The letter AF (Auto: Focus) stands for AF (Auto: Focus) and MF (Manual: Focus) stands for MF (Manual: Focus). Manual focusing function is particularly effective in macro photography, special effects shooting or shooting in dim environment.

Sixth, composition

Although many people now say "how to look good and shoot, don't worry about composition", the role of composition can not be ignored. Especially those basic composition skills are the basis of composition. No matter how you want to shoot in the future, you need these basic composition skills to support it. Here are some basic composition methods to help you consolidate your foundation.

① Jiugongge composition

When composing a picture, the horizontal and vertical directions of the picture are divided into three parts, and the intersection of each line is called "interesting center". When we appreciate or watch a photo, the first thing our eyes notice is the "interesting center", so we try to arrange our subject in the interesting center when taking pictures.

② Diagonal composition

Diagonal composition is very flexible, whether it is landscape photography or portrait photography, diagonal composition is used more. Diagonal composition can attract the attention of the audience, attract the audience to see the whole picture, and make the picture elastic at the same time.

③ Central component

The central composition is very simple, that is, putting the subject in the middle of the picture. Although this composition is plain, it is nothing new. But this composition is very useful when shooting buildings or small objects. For many novices who can't compose music, central composition is the safest way to compose music.

④ Picture composition

Frame composition can create a sense of occlusion and effectively concentrate the attention of the audience, which is very popular. In addition, the audience can also feel the photographer's point of view, which helps the audience and the photographer to have the same experience of the scene. Moreover, frame composition is not only through the use of windows, but also many objects can be used in life.

Seven, it's used up

It is said that photography is an art of using light, which is not only a basic skill, but also an important content to reflect the photographer's level. Next, I'll tell you about the skills of using light.

① Smoothing

Shun lighting means that the illumination direction of light is the same or basically the same as the shooting direction of the camera, and there is no obvious relationship between light and shade in the picture composition. Smooth lighting makes the brightness of the subject even and soft. However, the photos taken along the light are very common, which leads to the lack of three-dimensional sense and shaping. Sunlight can well show the shape and color of the subject. If you are not very accurate about the use of light, then I suggest you shoot with sunlight as much as possible.

② Side lamp

The light emitted from the left and right sides of the object at an angle of 45-90 degrees can be called side light. Side lights are ever changing. Just changing the angle of the light source slightly when shooting can create a completely different effect and add drama to the whole photo.

③ Backlight

From the light ratio, the subject and background are both in the dark or 2/3 of the area is in the dark, so the light ratio between light and dark is large and the contrast is strong. From the perspective of light effect, backlight produces contour light for opaque objects; Generating transmitted light for transparent or translucent objects; Produce flickering light on liquid or water. It can make the picture produce an artistic effect completely different from the actual light we see with the naked eye at the scene.

Photography professional knowledge 2 1, should the photos taken by mobile phones be late?

Nowadays, digital devices, such as mobile phones and cameras, are mostly gray because of the imaging principle of photosensitive elements. Then in this case, we should all do appropriate post-processing. There are many people in the society who are disgusted with the later period and think it is fraud.

In fact, photography belongs to art, and art comes from life and is higher than life. Living too much is not art, taking photos in the early stage is equivalent to collecting materials, and the later stage is a necessary means for the author to express his connotation. For example, if you cook at home, adding seasoning is to add soul to the dish, which is the same reason.

2. Is it photography with APP superimposed filter?

Many friends think it is very troublesome to learn manual color matching, so many third-party retouching software appeared at this time. These retouching softwares have built-in a large number of filters. You can import photos into the software and choose your favorite filters to superimpose them. This is a fool's operation.

The process of filter superposition can surprise everyone, but for ordinary people, it is impossible to tell whether the filter really suits their photo style. The filter maker made the filter according to the light, shadow, angle and color of the photo at that time, so it is really difficult to say whether it is suitable for your photo.

3. Why do photos taken by mobile phones look better than those taken by cameras?

Do you have such a question? Why the photos taken by mobile phones are much better than those taken by cameras in the same scene? Because the imaging of mobile phone is optimized by digital algorithm and image processor for many times, it is displayed on the screen of mobile phone.

To put it bluntly, while we are taking pictures with the mobile phone, the powerful system algorithm of the mobile phone will quietly carry out various retouching operations for you in the background, and the final effect you think will be taken directly by yourself. Actually, it's also a post-photo, but you didn't operate it yourself.

This camera can save photos in the original format. RAW format is an unprocessed original format, which can retain a lot of original information. A lot of space is reserved for later work. This kind of file data is very large. After a certain post-processing, his image quality will surpass that of the mobile phone many times.

4. Whether the RAW format of the mobile phone is the same as that of the camera.

Now more and more mobile phone manufacturers add raw format to their mobile phones. RAW is a format. Photos taken in this format are unprocessed documents. It must go through a series of post-operations before it can be published online.

Broadly speaking, the RAW format of mobile phones and cameras is indeed the same. But here I have to mention another knowledge point, that is the size of the photosensitive element. The volume and area of camera photosensitive element are much larger than that of mobile phone photosensitive element. There is a saying in photography that the bottom layer crushes people first, so we still can't use the image quality of mobile phones and cameras to PK.

Photography professional knowledge 3 monocular reflection observer system: this is the most common camera observer at present. It uses the mirror behind the lens to reflect the picture captured by the lens, and then refracts it with a pentaprism, so that we can see the upright image from the viewer.

Perspective observer system: it has no so-called mirror and pentaprism, and the light enters our eyes directly through the observer. When we take a close-up shot, the imaging range of the negative will be different from that of the framing, which is called parallax.

Binocular reflection observation system: This camera has an upper lens and a lower lens. The upper lens is the viewer, and the lower lens is the actual shooting. This system will increase parallax because of the different positions of the upper and lower lenses.

Focus: adjust the focus ring to make the image clearly imaged on the film through the viewer's preview. Manual focusing is to adjust the focus ring by hand to complete the focusing work, rather than relying on camera autofocus. Auto-focus is to adjust the focus ring by using the built-in motor drive without manual operation, but the auto-focus camera must cooperate with the auto-focus lens to play this function.

Principle of photographic imaging: The most primitive camera is a black box with a small hole. The light reflected by the scene passes through the small hole and then hits the photosensitive film. Because the light is emitted, it will continue to diverge through the small hole. The light originally emitted by points forms a circle on the photosensitive film, and the image is composed of many circles instead of points, which is naturally not clear enough. Therefore, a lens was invented to replace the circular hole. Monoconvex lens is the simplest lens, but it is only a little better than pinhole. If multiple lenses are combined to minimize the aberration of each lens, it is a compound lens commonly used by all cameras now.

Focal length: as far as a single lens is concerned, the distance from the focal point to the center of the lens is the focal length; Generally speaking, the focal length of a compound lens is the distance from the focal point to the aperture position, but it is actually the distance from the focal point to the rear node of the lens. The rear node of the telescope head is far in front of the front lens and the wide-angle lens is behind the last lens, so it is different according to the lens design.

Function and function of focal length: The focal length is directly proportional to the imaging size. The longer the focal length, the greater the imaging, and the shorter the focal length, the smaller the imaging.

The focal length of a lens is inversely proportional to the viewing angle. The longer the focal length, the smaller the scene angle, the shorter the focal length and the larger the scene angle.

The focal length is inversely proportional to the depth of field. The longer the focal length, the smaller the depth of field, the shorter the focal length and the greater the depth of field.

The length of focal length is inversely proportional to the strength of perspective. The longer the focal length, the weaker the perspective, and the shorter the focal length, the stronger the perspective. The length of the focal length is inversely proportional to the contrast. The longer the focal length, the smaller the contrast, and the shorter the focal length, the greater the contrast.

Depth of field: Focus on a scene and form a clear area before and after the scene. This blank area is called Quan Jingshen, or depth of field for short. Three basic factors that determine the depth of field:

Aperture-Aperture size is inversely proportional to depth of field. The larger the aperture, the smaller the depth of field.

The focal length is inversely proportional to the depth of field. The greater the focal length, the smaller the depth of field.

Object distance-The object distance is directly proportional to the depth of field, and the greater the object distance, the greater the depth of field.

Brightness: the brightness of the lens is the amount of luminous flux. The greater the amount of light entering the aperture, the greater the brightness, and vice versa. Brightness is calculated by the multiple of aperture coefficient, which is one of the important factors to determine the exposure.

Standard focal length lens: the viewing angle is about 50 degrees, which is also the viewing angle that a person can see with one eye without turning his head and eyes, so it is also called standard lens. The larger the camera frame, the larger the focal length of the standard lens.

Wide-angle lens: named for its wide shooting angle, it is suitable for shooting close-range and wide-range scenes, and can deliberately exaggerate the foreground to show a strong sense of distance, that is, perspective.

Telephoto lens: It is suitable for shooting distant scenes, and small depth of field easily highlights subjects with blurred background. Because the telephoto lens is too bulky, there is a design of telescope head, which is to add a negative lens in front of the lens and move the main plane of the lens forward, so that the lens can be obtained with a shorter lens body, thus obtaining the telephoto effect.

Reflective telescope head: another design of super telescope head, which uses a mirror to image, but because of the design reason, it is impossible to install the aperture, so the exposure can only be adjusted through the shutter.

Aperture: The lens of a camera has a device to control light transmission, which is called aperture. The aperture is large, and the light transmission is large; Turn it down, and the amount of light will be small. Small aperture and large depth of field, a clear sense of Ming Rui; Large aperture and small depth of field can make the subject stand out, showing a sense of blur before and after the subject.

The function of aperture: control the penetration of light and adjust the depth of field. The intensity of light passing through the lens to the film is inversely proportional to the square of the aperture coefficient. The depth of field is the range of clear imaging before and after the lens is focused, which is related to the lens focal length, aperture and the distance of the subject. The shorter the focal length of the lens, the smaller the aperture, the greater the depth of field and the greater the clear range, and vice versa.