When adjusting the white balance color temperature, please use the aperture first. Why do you drive to show a single shot when you take three photos?

SLR cameras (SLR cameras) are also called SLR cameras. Refers to a camera that uses a single lens and reflects light through this lens. The so-called "single lens" means that the photographic exposure light path and the framing light path * * * use one lens, unlike the paraxial camera or the double-reflex camera, the framing light path has an independent lens. "Reflection" means that a plane mirror in the camera separates the two light paths: when taking a view, the mirror falls, reflecting the light of the lens to the pentaprism and then to the viewing window; When shooting, lift the reflector quickly, and the light can shine on the film or photosensitive element CMOS or CCD.

Operation mode of single-sided camera

1, automatic (fully automatic mode)

This is the most convenient shooting mode. All you have to do is take a picture, focus and press the shutter. As for white balance, shutter, aperture, ISO value, etc. , all to the camera for automatic processing. In this mode, because of the inaccurate parameter setting, the imaging is very general and has no characteristics.

2, P (program automatic exposure mode)

This mode allows the camera to automatically set the shutter speed and aperture size, which is the same as the automatic mode. If the correct exposure cannot be obtained, the shutter speed and aperture value on the LCD screen will be displayed in red. At this time, many parameters can be adjusted manually.

For example, in the case of incorrect exposure, the image can be exposed correctly by turning on the flash, manually changing the ISO value, changing the metering mode and making exposure compensation. You can also set the white balance to display more realistic image colors.

You know, photo effects (such as black and white) and continuous shooting mode cannot be adjusted in automatic mode.

3. TV (shutter priority shooting mode)

In shutter priority mode, first set the shutter speed, and the camera will automatically select the appropriate aperture value. Faster shutter speed can capture instantaneous images of moving objects. A slow shutter speed will produce a flowing effect, which is often used when shooting night scenes.

After setting the shutter speed, press the shutter half way. If the aperture value is displayed in red when focusing, the image exposure is incorrect. At this time, you need to change the shutter speed value until the aperture value is displayed as white. This is because the aperture value also has a certain range.

4.Av (Aperture Priority Shooting Mode)

Aperture priority, that is, the required aperture size is set in advance, and the digital camera will automatically adjust other parameters according to the shooting conditions. Using this mode, the depth of field can be effectively controlled. Choose a lower aperture value (increase the aperture), the depth of field becomes smaller and the background becomes softer. Choose a higher aperture value (reduce the aperture), the depth of field becomes larger, and the whole foreground and background are clear.

If the shutter speed is displayed in red on the LCD screen, it means that the image exposure is incorrect, and the aperture value needs to be changed until the shutter speed is displayed in white.

5, M (full manual shooting mode)

This mode requires us to manually adjust the parameters of shutter and aperture, and it is difficult to expose correctly without considerable photographic experience. But learning photography in this mode is the fastest progress.

The automatic exposure function will automatically calculate the standard exposure according to the selected metering method. When the shutter button is half pressed, the difference between the standard exposure and the selected exposure will appear on the LCD screen. If the difference exceeds plus or minus 2 steps, "-2" and "+2" are displayed in red. At this time, the shutter or aperture value must be modified until the exposure is correct.

6. Portrait shooting mode

Use this mode if you want to make the subject clear and the background blurred. In order to obtain the best effect of gradually softening the background, the upper body of the subject should occupy the viewfinder or LCD screen as much as possible when composing. When the zoom magnification is set to maximum, the effect is more obvious.

7. Horizontal mode

When shooting in this mode, the aperture and shutter value are moderate, which can make people and scenery image clearly.

8. Night shooting mode

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This mode is also called "slow shutter flash synchronization mode", which is most suitable for taking night photos with foreground people. The camera will shoot at a slow shutter speed and flash, so that the subject and background can be properly exposed.

Light. In order to prevent photos from blurring, a tripod must be used to keep the fuselage stable and ensure sufficient exposure and image quality. In addition, when the flash flashes, people can't move immediately, otherwise the image will be blurred. such as

If you just shoot at night, don't use the flash. Because the effective distance of the flash is short, it is easy to ignore the scenery behind the subject.

9, high-speed shutter shooting mode

This mode is used to shoot fast moving objects, such as catching water droplets or moving objects.

10, slow shutter shooting mode

This mode is used to shoot moving objects and make them appear blurred, thus creating soft effects, such as streams and rivers.

1 1, SCN (special scene mode)

There are six modes to choose from: plants, snow, beach, fireworks, diving and indoor.

12, panoramic shooting mode

This mode is mainly used for landscape shooting. It can combine several pictures taken into a panoramic image.

When composing, make each connected picture overlap 30% to 50%, and the vertical error is limited to 10% of the image height.

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After shooting the first image, the first image will remain on the LCD screen of the camera, and the second image can be shot by composition. Panoramic images can also be taken in the same way. For best results, water is generally used.

Move (rotate) the camera horizontally to take continuous images. Of course, a tripod is indispensable. Don't change the focal length when shooting, otherwise the adjacent pictures will be deformed and cannot be connected.

To create a panoramic image, it needs to be spliced on the computer. This can be done by using the included PhotoStitch software.

13, camera mode

This mode can shoot audio short films and record them in AVI format with the highest resolution of 640x480. Because the capacity of the memory card is limited, it can only be meaningful and experience the happiness of shooting dynamic images.

From the point of view of general professional control, taking Nikon camera as an example, four modes are mainly used: P, S (Canon is TV), A (Canon is AV) and M. I believe A(AV) and M are the two modes used by most photographers. In A(AV) mode, the user only needs to control the aperture size at any time according to the need of depth of field, and the shutter value of the camera will be adjusted at any time according to metering. If the shutter value is lower than the safety shutter (the reciprocal of the focal length of the lens), the ISO sensitivity will increase (the higher the ISO, the greater the noise generated by the shutter). Of course, if the light is too dim, you need a tripod to fix the camera. M mode is based on the user's flexible control of the camera according to his own ideas. Of course, by adjusting the aperture and ISO, you can shoot while ensuring the shutter speed.

SLR cameras also have white balance to control the color temperature of images. Let's know about white balance. First, let's assume that there is an incandescent light source in this scene. The color temperature of incandescent lamp is about 3200K, and the light it emits contains red and orange components.

At the same time, there is a white paper in this scene, which can reflect all the light shining on it, so the white paper will appear red and orange, but when our eyes look at this white paper, it will still be white instead of white.

It is red and orange, because our eyes have strong visual compensation in physiology. It can be compensated by cyan complementary color, so that the white paper is still white under the irradiation of incandescent lamp, which is white balance. Then the human eye.

How is this color temperature compensation function realized? To understand this problem, we should start with the structure of the human eye. Physiologically, the human eye consists of cornea, anterior chamber, iris, lens, vitreous body and retina.

When the human eye observes the scene, the light from the scene passes through the cornea, aqueous humor, pupil, lens and vitreous body and reaches the retina. The visual cells of the retina are stimulated by light, converted into nerve impulses, and then transmitted through the optic nerve.

Leading to the visual center, until the visual cortex of the brain, people have vision. Among them, the retina is the key to produce vision, and there are many visual cells on the retina, which are mainly composed of cone cells and cylindrical cells.

Cells do not distinguish colors, but are sensitive to weak light. Cone cells can distinguish colors and feel strong light, but they are not sensitive to weak light. They are composed of red sensitive R(700~600nm), green G(600~500nm) and blue.

B(500~400nm) color light consists of three kinds of cells. We know that white is achromatic, and black, white and gray are achromatic. They do not selectively absorb and reflect the spectral components of the light source, but equally absorb and reflect them.

Reflect various spectral components. When all spectral components are absorbed, the surface of the object looks black; Part of it is equally absorbed, and part of the surface with equal reflection is gray; Reflect most, but absorb a very small part.

Is white, then we can approximately think that white reflects all the colored light. In our hypothetical scene, white paper looks red and orange because there are many red and orange components in the light of incandescent lamps. In order to produce a white paper

To present the original white, our eyes need to automatically increase the number of blue light and green light, so that the number of red, green and blue light reflected by them is equal, thus restoring the original white of white paper and supplementing it with this color light.

Quantity is the correction factor of white balance. Under the irradiation of this incandescent lamp, if the white color of the white object is accurately restored, then the colors of other objects will be accurate by using the determined white balance correction coefficient.

Reduction and reproduction.

We know that any camera is an imitation of the human eye, and SLR cameras are no exception. In order to simulate the red-sensitive, green-sensitive and blue-sensitive cells in human eyes, Bayer filter is set in front of CMOS, the imaging component of the camera. This filter consists of many red, green and blue squares, and each square corresponds to a photodiode (also called a pixel) on CMOS. When light passes through the Bayer filter,

The light passing through the red square will turn into red light, the light passing through the green square will turn into green light, and the light passing through the blue square will turn into blue light, so that the light will be decomposed into three colors: red, green and blue.

It is recorded by the photodiode on CMOS and finally converted into an electrical signal for storage. From the recording process of colored light, each photodiode can only record one of three colors: red, green and blue, but we know that in the final form.

Every pixel in the finished image consists of three colors: red R, green G and blue B. How can the camera change from monochrome on the actual pixel (photodiode on the camera CMOS) to three colors on the image pixel?

This conversion process is realized by an algorithm built in the camera. Different cameras have different algorithms, so the color photos taken by the camera are actually from the adjacent red, green,

Calculate blue pixels. Like the human eye, the camera should also consider the problem of white balance when recording red, green and blue. There is a white balance adjustment mechanism inside the camera. In most cameras, enter white.

Balance menu, you will see a variety of white balance setting options, which can be roughly divided into three categories, one is automatic white balance, which is a way for the camera to automatically set white balance, and the other is some built-in common white balance, such as

For sunshine, shadows, cloudy days, tungsten lamp, fluorescent lamps, etc. , you can choose the corresponding options in the corresponding shooting occasions. There is also a custom white balance that allows users to shoot reference white objects or input directly.

Sets the color temperature of the white balance. Automatic white balance of the camera automatically measures the color temperature of the scene through the camera's built-in color temperature measurement system, and then automatically controls the camera to obtain correct color reproduction. The essence of automatic white balance is to compare with "scene"

The light with the same relative spectral power distribution as the object illumination source is compensated to be visually neutral, with high brightness being white, medium brightness being gray and low brightness being black. When you customize the white balance, you can not only shoot a square with reference to a white object.

Formula to determine the white balance, you can also directly enter the color temperature value manually. When the color temperature value is input, the camera regards the input color temperature as white light. If the actual lighting source in the shooting occasion is lower than the color temperature, the photos taken will be biased.

Warm, photos taken above this color temperature value will be cold. When the white balance of the camera is directly set to the color temperature value of the lighting source, the white objects in the scene are faithfully represented as the original white in the taken photos.

In this way, the colors of other objects in the scene will be accurately restored. Suppose that the color temperature of the light source we use to shoot the scene is 5500K, then when the color temperature of the camera is also set to 5500K, we shoot.

The colors of all objects in the scene will be faithfully represented. If the color temperature of the camera is set to 6500K, then the camera regards 6500K as white, because the actual color temperature of the light source is 5500K, which is less than.

6500K, so there are more red and orange light components in the picture, and the whole picture is warmer. On the contrary, if the color temperature of the camera is set to 3500K, then the camera regards 3500K as white light and actual light.

The source color temperature of 5500K is greater than 3500K, so the photo contains more blue and cyan light components, and the overall picture is cold. In the previous explanation of the color temperature, we mentioned that the color temperature of the light source gradually increases from low to high.

The color will gradually change from dark red to red, then to orange and yellow, then to white and finally to blue. However, when the color temperature is set in the camera, the larger the color temperature value is set, the warmer and smaller the photo is.

The colder the photo, it seems to violate the law of color temperature. In fact, from the example we gave above, you can understand why this is the case. It does not violate the corresponding law between color temperature change and color.

Summarize color temperature and white balance:

First, in a shooting scene, only the inherent white of white objects is faithfully reproduced in the photo, and the colors of other objects will be truly reproduced.

Secondly, the same white object shows different colors under the illumination of light sources with different color temperatures (here, it refers to the color presented, not the color seen by human eyes). Under the high color temperature light source, due to the light emitted by the light source,

There are relatively many blue and cyan light components in the line, so the proportion of blue and cyan light reflected by the white object is more, which makes the white object appear cyan objectively and the overall tone is cold; Under the illumination of light source with low color temperature

Under irradiation, because the light emitted by the light source contains more red and orange light components, the white object reflects more red and orange light, which makes the white object objectively appear red and orange, and the overall tone is warmer. for

In order to make the white object still appear as its own inherent white at different color temperatures, it is necessary to readjust the proportion of red, green and blue signals received by the camera, which is the white balance setting of the camera.

Thirdly, when setting the white balance of the camera by inputting the color temperature value, the color of the object in the whole scene will be truly restored and reproduced only when the input color temperature value is consistent with the color temperature value of the actual light source. If the input color temperature value is higher than the actual light source, the photos will be warmer; If the input color temperature value is lower than the actual light source color temperature value, the color tone of the photo taken will be cold.

Finally, accurately setting the white balance is only used to help you accurately and truly restore the inherent color of the subject. Sometimes we need to do this, such as taking pictures of clothes and products, and sometimes we need to take pictures.

We deliberately set the "wrong" white balance to create an atmosphere in the photo to meet the needs of artistic expression. What kind of white balance to set is determined by the shooting requirements, but in any case, understand the camera white.

The principle of balance setting will help you quickly master the use of white balance and take photos that meet your needs. Of course, if you are too troublesome, as long as you shoot in RAW, this is not a problem, and you can adjust it at any time in the software later. (The original file is in an unprocessed and uncompressed format. It is a file that records the original information of digital camera sensor and some original data (such as ISO setting, shutter speed, aperture value, white balance, etc.). ) camera shooting production.

RAW is a format commonly used by professional photographers, because it can save the local shooting data information, so that users can design photos greatly in the later stage, such as adjusting white balance, exposure, color contrast and other settings.

It is not suitable for novices to remedy failed photos, and no matter what changes are made in post-production, photos can be restored to their original state, and they will not be lost, and they are not afraid of losing photos because of mistaken storage.

RAW also has the advantage that it can correct the loss of light and the distortion of the lens through software. )