Basic knowledge content of photography technology

Basic knowledge content of photography technology

With the continuous improvement of people's living standards, more and more people have the conditions to learn new skills in their leisure time. Learning anything starts with the most basic knowledge. For example, if you want to learn photography, you must first master the basic theoretical knowledge, and then share the basic knowledge of photography.

Basic knowledge of photography technology 1 1. Correct camera holding method

In the basic knowledge of shooting, the most important thing is to hold the camera steady. No matter how well other photographic elements and techniques are mastered, as long as there is vibration at the moment of shooting, the quality of photos will be greatly reduced because of blurred images.

Although tripods can be used to reduce the possibility of vibration, most of them are shot with hand-held cameras, and photographers are often not allowed to spend time placing tripods and fixed cameras at "decisive moments".

Compared with traditional cameras, digital cameras require higher shooting stability. This is because electronic components need extra time to store information, which is often called "time lag".

1, the correct posture of the machine.

Whether standing, sitting or kneeling, the correct posture for holding the machine should be:

(1). Hold the handshake position on the camera side with your right hand, and touch the shutter button with your index finger to shoot at any time.

(2) Hold the bottom of the fuselage with the palm of your left hand, and hold the camera with your thumb and forefinger to stabilize the lens.

(3) Keep your hands and upper arms close to your body, and try to keep them drooping naturally and close to your body. Never shrug your shoulders. Because the shoulder is lifted for a long time, the shoulder will feel tired and it is more difficult to stabilize the camera.

(4) When holding the camera vertically, generally, the left hand is down and the right hand is up, but also pay attention to the left arm close to the body.

2. Matters needing attention when standing or sitting down for photography

(1), when standing for photography, you should stretch your feet slightly, or stand back and forth, so that you can put your whole body weight on your feet. If you can rely on some fixed objects, such as leaning against the trunk or wall, the effect is better.

(2) Sitting photography has high stability, but foreign objects can still be used to further stabilize the body. A chair back or a table is a good choice.

3. Precautions for kneeling photography

When kneeling, the left foot should be arched, the right foot should kneel on the ground, and the left hand at the bottom of the fuselage should be lifted and supported on the arched left foot. In general, it is difficult to keep your body steady on your knees. It is best to rely on fixed objects, such as trees and walls.

4. The important role of video tape

Put the camera strap on your wrist, hold it in the tiger's mouth for two turns and then tighten it. After putting your thumb through the strap, hold the camera tightly, so that the camera can be integrated with your right hand, which can not only reduce the tremor of your hand, but also hold the camera when you accidentally let go, so as not to fall to the ground and be damaged.

Second, the use of light.

Photos are artistic products of light and shadow, and it is not an exaggeration to call light the soul of photography. To take good photos, you have to master the key element of light.

1, the properties of light

(1) direct light

On sunny days, the sun shines directly on the subject without any obstruction, and the light-receiving surface will produce bright shadows, while the light-receiving surface will form obvious shadows. This light is called "direct light". Under the "direct light", there will be a very obvious contrast between the light-receiving surface and the non-light-receiving surface, which is easy to produce a three-dimensional sense.

When the sun is blocked by thin clouds, the sunlight will still diffuse through the white clouds, and the resulting illumination contrast will be reduced, which is very suitable for portrait photography.

(2) Scattered light

On cloudy days, sunlight is blocked by clouds, so it can't shine directly on the subject. It can only shine on the subject through the intermediate medium or through reflection, and the light will have a scattering effect, which is called "scattered light". Because the light receiving surface and shadow surface formed by scattered light are not obvious, the contrast between light and shade is weak, and the change of light and shadow is soft, so the effect is flat and soft.

"Direct light" will produce light with strong contrast, resulting in thicker shadows, less tonal changes, and harder lines and tones of the captured image. And "scattered light" will produce light with weak contrast, so the shadow is shallower, the color tone changes more abundantly, and more and more soft image lines and colors will be obtained. So photographers should choose the right light according to different situations.

2. Different directions of light projection

Shooting the same scene, using light projected in different directions will produce different effects.

(1) Guang Shun

The light coming out from the back of the camera and facing the subject is called "smooth light". The characteristics of "Guang Shun" lighting are: most objects are directly illuminated, the shadow area is not large, and the color of objects is relatively clear. The contrast between light and shade formed by this kind of light is weak, and the three-dimensional sense of an object can not be reflected mainly by illumination light, but by its own ups and downs. So the three-dimensional sense is weak.

(2) Front side lamp

The light from the left or right rear of the camera to the subject is called "front light". Most objects that receive light will receive light, resulting in a brighter surface, so the color tone is brighter, and the area of the object that is not exposed to light will not be too large, but it can already show the light and dark distribution and three-dimensional shape of the object. This kind of light can not only keep the bright hue, but also show the three-dimensional form of the main body.

(3) Side lights

The light from the left or right side of the camera is called "sidelight". It will make half of the subject receive light, while the other half is in the shadow, which is beneficial to show the ups and downs of the subject.

Because the "side light" illumination increases the shadow area of the object, the color of the picture is not bright or dark, and the light and dark are mixed, which is not as bright as the "front light" and "front side light", but it is not too gloomy. Three-dimensional form will be better.

(4) Side backlight

The light from the left or right front of the camera is called "side backlight". It makes the object produce a small part of the light receiving surface and most of the shadow surface, so the color tone will be darker. This kind of lighting will have a better stereoscopic effect on the object than "smoothing", but it is still weak.

(5) Backlight

"Backlight" is the light from the back of the subject and the front of the camera. Most objects are in the shadows. Because the light is weak, the three-dimensional sense is weak, and the tone is gloomy. However, "backlight" can be used to sketch the silhouette and outline of an object, and it can also highlight the texture and shape of the object and clearly show the lines of the object. Using "backlight" in clear weather will produce a strong contrast.

(6) dome light

The light from above an object is called "top light". The sunshine at noon is a good example. "Top light" often causes a strong shadow to the subject. If it is used in portrait photography, it will form a dark shadow under the nose, eyes and jaw of the face.

(7) Bottom lamp

The light source of "bottom light" is located below the subject. This kind of light is rare in daily life experience, so it has weird and dramatic effects and is rarely used in general photography.

3. Contrast of light

"Contrast" refers to the tonal relationship between "brightest" and "darkest" on the subject. The so-called "strong contrast" means that the brightest part and the darkest part of the light on the subject are very different, and the change from the brightest to the darkest is very strong, and the contrast is very strong. Relatively speaking, "weak contrast" means that the difference between the brightest part and the darkest part is not too big, and the change from the brightest part to the darkest part is very smooth, which makes the tone very rich.

Third, photographic composition

Composition is a process of dealing with the relationship between people, scenery and things in the limited space of photos, and arranging them in the best position in the picture to form a specific structure of the picture.

The main purpose of composition is how to emphasize and highlight the theme scenery, and at the same time, arrange the trivial things as a foil. Good composition makes photos look even, stable, comfortable and regular, and can guide the line of sight to the theme point. Improper composition will lead to disorder, imbalance between left and right, top-heavy, lack of visual focus and other problems because of too many themes.

1, notes for composition

To get a good photographic composition, we must pay attention to the following points:

(1) The photo should not be too monotonous, otherwise it will look dull. But it can't be too complicated, otherwise it will make people feel very confused.

(2) Choose a suitable background. A good background not only helps to set off the theme and highlight the protagonist, but also enriches the content of the photo and adds color to the picture.

(3) Understand the relationship between people, scenery and things in the photos and make appropriate arrangements, so as to effectively express the theme and avoid usurping the role of the host.

(4) Consider the color contrast of each scene. Sharp contrast helps to highlight the theme, but if the colors are confused, it will have the opposite effect.

(5) It is necessary to master the illumination angle of light and the shadow generated, which will affect the color and effect of photos.

(6) We should make more use of the changes of illumination, perspective, overlap and light and shade, which will help to increase the three-dimensional sense in plane photos.

2. Create different compositions from different shooting angles.

Most themes are three-dimensional, and they present many faces. There are front, side, back, top and bottom. Different shooting angles of the same object will also make the picture show a variety of composition effects. Therefore, before shooting, we should choose different directions and angles to observe the comparison object, find out the best, most expressive and vivid viewpoint, and find the most suitable composition.

(1) Frontal shooting.

Frontal photography is one of the most commonly used photography angles. Frontal shooting can produce a solemn and smooth composition effect. However, smooth lines and symmetrical structures will also be dull due to lack of perspective. Moreover, in many cases, because the light receiving conditions of objects are similar, the stereoscopic effect of objects cannot be highlighted.

(2) side shot.

With the inclined photography angle, the original parallel lines on the picture become diagonal lines, which gives people a sense of depth and can lead people's eyes to the depths and enhance the three-dimensional sense. And the line of sight extending along the diagonal will also make the picture vivid. With the change of oblique azimuth, the perspective effect will also change interestingly.

(3) look up and shoot.

Looking-up shooting refers to shooting at an oblique angle, which is mostly used to shoot tall scenes. This shooting angle can not only capture the panoramic view of the tall scene, but also form a sense of perspective in which the lines perpendicular to the ground converge upwards. It can also highlight the towering characteristics of objects and increase the sense of oppression.

(4) Shoot from above.

Looking down means shooting from top to bottom. Aerial photography can shoot a wide range of scenery, so it is often used for wide-angle landscape photography. Using overhead photography in portrait photography can bring slim effect to the protagonist.

3. Composition of "Three Points"

The "trichotomy" was put forward by Greek mathematicians. Photographers can often take many harmonious and pleasing photos by applying it to the composition of photos. The specific method is: divide the picture into 9 squares with the same size with two straight lines and two horizontal lines. When shooting, put the subject at the intersection of a straight line and a horizontal line.

Basic knowledge of photography technology Content 2 Typical application of exposure compensation in real shooting

1 Increase exposure compensation to shoot fair-skinned portraits.

Portrait photography, exposure compensation is increased by +0.3EV~+0.7EV, which can shoot beautiful human skin color. The method is to measure the exposure value of the skin (especially the spot metering method is more accurate), and then increase a certain EV value, which can make the skin look whiter.

The above is only for shooting beautiful women and children. If you want to photograph old people or people with dark brown skin, or people in mines or underground coal mines, you should make negative exposure compensation to make their skin look more saturated and deeper, so as to highlight their own age, race and professional characteristics.

Increase exposure compensation and shoot white clouds, white fog and snow scenes.

Shooting white clouds and fog scenes is different from ordinary landscape photography, and usually the pictures to be shot are high-profile types. Therefore, when shooting in evaluation metering mode, the picture may become dark, so the fog in the picture should be measured and the exposure compensation should be increased appropriately.

The same problem exists in shooting snow scenes. Because the brightness of snow is very high, exposure according to the photometric value calculated by the camera itself will lead to underexposure, which will make the photographed snow gray. Therefore, exposure compensation function is generally used to correct exposure when shooting snow scenes. According to the proportion of snow in the picture, it is usually necessary to increase the exposure compensation of 1 to 2 blocks. The left side shows the beautiful scenery that can only be taken by adding exposure compensation.

3 Reduce exposure compensation and make the picture more colorful.

Exposure parameters have a great influence on the color of the picture. The more exposure, the brighter and lighter the color of the scene in the picture. On the other hand, if the exposure is insufficient, the color of the scene in the picture will appear dull and rich.

Therefore, on the basis of normal exposure, properly reducing the exposure compensation can make the color of the subject look richer.

If you shoot the blue sky, you can make the sky in the picture look bluer by reducing exposure compensation. If you shoot flowers, you can compensate by reducing the exposure, so that the colors of flowers in the picture look brighter.

4. Reduce exposure compensation and take simple pictures with dark background.

When shooting flowers, still life and other subjects, in order to make the picture more concise, we can use the spot metering mode to aim at the relatively bright area of the subject in the foreground for metering, so as to ensure the accurate exposure of the subject. Then, by compensating the negative exposure of the photo, the background becomes dark or even pure black due to underexposure, thus highlighting the subject in the foreground.

5 emphasize contour effect by reducing exposure compensation

When shooting backlit works, exposure control can not only show the overall environment including details, but also treat the picture as a silhouette. The former needs to increase exposure compensation, while the latter needs to decrease exposure compensation.

Basic knowledge of photography 3 1. The wider the light source, the softer the light. Conversely, the narrower the light source, the harder the light.

A wide range of light sources can weaken shadows, reduce contrast and suppress textures, while a narrow light source has the opposite effect. This is because the wider the light source, the more directions the light shines on the object, which will increase the lighting in the scene and reduce the shadows.

Tip: Arrange the portrait theme next to a big bright window to avoid direct sunlight. Windows can play the role of soft boxes, and the studio does not need special equipment.

The closer the light source is, the softer the light is.

Conversely, the farther the light source is, the harder the light is. This is because the closer the light source is to the subject, the bigger it is, and the wider it is; The farther the light source is from the subject, the smaller it is, that is, the narrower it is.

Take the sun as an example. The diameter of the sun is 109 times that of the earth. It's a fairly wide light source! However, the sun is 93 million miles away from the earth (about 65.438+0.5 billion kilometers), accounting for only a tiny part of the earth's sky, so the light is very hard when the sun shines directly on objects.

Tip: When you shoot a portrait indoors with existing lighting, you can change the distance between the light source and the subject to make the light of the photo more moving.

3. Diffuse reflection can disperse light, making the light source wider and the light softer.

The essence of using diffuse scattering to disperse light is to broaden the light source, so as to achieve the purpose of softening light. When clouds block sunlight, the shadow on the object will be obviously reduced, and if there is fog, the shadow will disappear. Clouds, gloomy skies and fog will diffuse light, and diffusion will spread light in all directions. On cloudy and foggy days, the whole sky will become a very broad light source and a natural soft box.

Tip: materials such as translucent plastic or white fabric can be used to diffuse strong light. You can add a soft mask in front of the artificial light source, such as a studio flash; If you are in bright sunlight, you can also use a hood or soft box to soften the light.

4. Reflect diffused light

Shooting a narrow beam on a large frosted surface (such as a wall, roof or frosted reflector) will spread to a wider area when reflected.

But if you use a smooth reflector, the light will still be narrow after being reflected. A mirror is an extremely smooth reflector. The light it reflects is almost as narrow as the incident light.

Tip: Knead a large piece of aluminum foil into a ball, spread it out and wrap it on a piece of cardboard, and a soft light reflector will be made. Although the diffusion effect of this self-made reflector is not as good as that of the white matte reflector, it can add shiny spots to the photos.

5. The farther the light source is, the faster the light decays and the darker the subject is.

This law points out that the illumination of an object is inversely proportional to the square of the distance. It sounds complicated, but it's actually very simple. For example, if you increase the distance from the light source to the subject by 1 time, the light falling on the subject is only a quarter of that before increasing the distance.

In other words, the light will decay rapidly with the distance from the light source. We should remember this rule. If you want to move the light source or the subject, you must change the quality of the light.

It should also be noted that even if a smooth reflector is used, the distance traveled by the reflected light will increase.

Tip: When shooting portraits outdoors in bad weather, you should use a flash (hot boots or pop-ups), which can eliminate the shadow on the face of the person and will not affect the exposure of the background, because the light emitted by the flash can be ignored when it reaches the background.