Basic knowledge of photography for beginners

1. About the aperture and shutter aperture of digital cameras:

The size of the aperture is a parameter that controls the light of the camera lens. To put it bluntly, the size of the aperture will determine the strength of light passing through the lens. So you can easily imagine that the larger the aperture, the stronger and weaker the light projected onto the CCD photoreceptor of the digital camera through the lens. Then its size will directly affect the imaging quality of the digital photos we take. For example, when the shutter time is the same, the larger the aperture, the brighter the photo. If the aperture is too large, there will be overexposure. Whether it is a traditional camera or a digital camera, the aperture is made of letters. f？ And the size of the central aperture of the aperture is expressed by the corresponding value, that is? F+ value? . It is worth noting that the smaller the aperture value, the larger the aperture, and the more light entering, and vice versa. So, what do you usually say when shooting? Increase the aperture? It means reducing the numerical value of the aperture and increasing the aperture. For example, from f5.6 to f4, or a higher level of f2.8. The difference of aperture from closed to open, and the influence of using different aperture values on aperture size. From the upper left to the lower right of the figure, the aperture size is in different states of closed aperture, f 1 1, f8 and f4 respectively. From this, we can also understand that the larger the aperture, the stronger the light projected on the CCD photoreceptor of the digital camera.

Shutter:

Shutter speed is also a parameter to control exposure time when taking pictures. In order to make it easier for everyone to understand, we can also say that the shutter is the control time for the camera to keep the currently set aperture size. For the expression of shutter speed, it is also set with corresponding numbers, such as1/4s,1/60s, etc. They represent the time to keep the currently set aperture size at 1/30 seconds and 1/60 seconds respectively. Therefore, it is not difficult to see that using different shutter parameters to maintain the aperture length of the unit aperture can also control the amount of light entering during shooting, that is, exposure. The above-mentioned 1/30 seconds is twice as long as 1/60 seconds, and at this time, the amount of light passing through the aperture of the unit aperture is twice as high, so conversely,115 seconds is half as long, and the amount of light passing through the aperture of the unit aperture will be reduced by half. In actual shooting, we can achieve different effects by adjusting the shutter speed, such as seemingly flowing? Car and? Or solidified water droplets, respectively, with a slow shutter and a high (fast) shutter. Of course, when using, we should pay attention to the reasonable cooperation between shutter and aperture, which is what we should focus on in the future. Let's talk about how to coordinate the relationship between them in practical application to better achieve the best exposure effect of photos. First of all, it depends on our creative thinking. For example, if we intend to capture a faster moment, the first factor to ensure is the shutter speed. For example, the shutter speed of1125 seconds can basically capture the walking movements of pedestrians without making the characters virtual. After determining the shutter speed, select the aperture size according to the current light and the required depth of field effect. In fact, through the combination of different shutters and apertures, the exposure is the same, but they are suitable for different shooting environments and shooting effects. For example, if you use the shutter of 1 1 25 seconds and the aperture of f11in sunny conditions, you will get the same exposure as the shutter and aperture of 1/250 seconds and f8 respectively. Depth of field, which we mentioned in the last paragraph? Depth of field? Reasonable use of the concept of depth of field effect in shooting can play a very important role in our photos, because it can highlight the object you want to shoot. Depth of field refers to the distance between the farthest part of the image and the nearest part in a lens focus adjustment, and this part of the picture should have acceptable clear details. In practice, the larger the aperture, the smaller the depth of field; The smaller the aperture, the greater the depth of field. In addition, the depth of field has two important functions: 1, the depth of field is smaller when the subject is in a far position; 2. If the distance between the aperture and the scene is the same, the longer the focal length of the lens, the smaller the depth of field. So now we can know that the control of depth of field (also known as depth) is actually the control of aperture size.

Summary:

Operation: In addition to automatic shooting mode (aperture and shutter are automatically adjusted by the camera), there are three operation modes for using aperture and shutter: aperture priority, shutter priority and manual mode. Aperture priority: As the name implies, aperture priority is based on the aperture value set manually by ourselves, and then the digital camera automatically gives the shutter parameters according to the environment and light at that time. In the same environment, the smaller the aperture, the less light enters, and the camera will extend the exposure time of the shutter.

Digital cameras generally use aperture first? Answer? To show. Shutter priority: similar to aperture priority, shutter priority means that we set the shutter speed manually, and the aperture size is automatically matched by the camera. Under normal circumstances, if you shoot by hand, the shutter speed should not be lower than1/60s, otherwise the camera will be unstable and the picture will be blurred. Of course, if you have enough strength or use a tripod, you don't have to worry about stability.

Digital cameras generally use shutters first? s？ To show. Manual mode: The aperture and shutter of the camera are set by yourself, which is a full manual mode. However, the level and requirements for users are relatively high, but fortunately, digital cameras can take pictures for free and can be taken immediately, so sometimes they may be used to try their hands. Digital cameras generally use manual mode? m？ To show.

2. Explanation of basic camera terms about ISO (1)

First of all, let's talk about the adjustment of ISO. The adjustment of ISO setting is mainly affected by two aspects. The first is the trouble of insufficient light, and the second is the slow shutter speed. In this case, if a tripod or digital camera can be fixed, you can shoot by adding an aperture shutter or a slow shutter. But in the absence of tripod support or hand-held digital camera can not guarantee stable shooting, you have to choose a higher ISO to solve this problem. Remember, if you want to get a clear picture, you should try to shoot with a low ISO setting. For example, if you want to shoot a moving object on a cloudy day or at sunset, the shutter speed setting is preferably1125s. However, under the setting of ISO50 or ISO 100, even under the maximum aperture setting, the digital camera will not reach this shutter speed, but shoot with a slow shutter. At this time, we can only improve the ISO setting to get a fast shutter, so as to capture fast moving objects. However, the adjustment of ISO should be gradual. First move to the nearest gear to see if you can achieve your shooting intention. If it's not ideal, move it up one notch, so as to ensure the best ISO setting for shooting. Of course, in any case, the increase of ISO will lead to the increase of noise, so we have to understand the advantages and disadvantages of ISO changes.

In short, the increase of ISO setting will lead to the increase of noise. Of course, in the case of poor lighting conditions, the increase of ISO can improve the shutter speed and realize the reliability of shooting. Remember, in the dark part or monochrome area of the photo, the performance will be more prominent and the noise phenomenon will be more obvious. The photos taken at low ISO are clean and neat, but it is best to use a tripod for low-light assisted shooting.

(B) About white balance

Photos taken in the fluorescent room will appear green, while photos taken in the shadow of the sun will appear blue inexplicably. I think all my friends who have just played with digital cameras have probably encountered this situation. What is the reason? White balance? In terms of settings. What is the function that can compensate for this phenomenon? White balance? . you like

If you don't want your skin to be weird when shooting, then come with us to learn what white balance is. White balance control is to make the color of photos taken under various light conditions completely consistent with the color of the scenery seen by human eyes through image adjustment. Simply put, white balance means that no matter what the ambient light is, it still puts? White? Defined as? White? Function, so as to ensure the accuracy of color reproduction. Generally speaking, when adopting the automatic mode, the digital camera we use will also adopt automatic white balance, which is easy to make mistakes in special circumstances. At this time, it is suggested that you call the preset white balance value in the digital camera, including indoor incandescent lamps, outdoor sunny days, hotels and other common environments. After setting the white balance correctly, the color performance is more natural than that on the right. However, white balance has many other uses. For example, different white balance values will cause color cast in photos, and using this feature, we can produce some special effects in our works, which is often more natural and convenient than using small accessories such as color filters. Using yellow custom white balance to produce blue light and light blue custom white balance to produce warm orange red light, we can artificially control the color shift of photos. To make the photo softer, use light blue objects to define the white balance. To make the photo deeper, use yellow to define the white balance.

In some shooting environments, the preset white balance value of digital camera may not be enough, and white balance is a very abstract concept, which is difficult to describe with simple values. In addition, you can use the white balance capture function of digital camera, which is also the most accurate way, but it is relatively cumbersome to use. First, find a white object that you think is the most standard, usually a white paper or plaster sculpture. Then turn on the white balance capture function of the digital camera and aim the lens at the standard white object. At this time, the digital camera can accurately capture the white balance parameters in the environment at that time. Mastering the white balance, the photos will have accurate color performance.

(3) About exposure compensation

Concept of exposure compensation (EV): Photography is actually a process in which a photographer uses his own photography technology to calculate the ambient light and capture the scene image through photographic equipment. This process is related to the aperture value of the device (controlling the luminous flux entering the camera per unit time), shutter speed (exposure time) and ISO (sensitivity to light). Nowadays, traditional devices and DC will calculate the ambient light through their own internal programs, and automatically adjust the aperture, shutter and even ISO value. However, in the Gao Fancha environment with complex light and strong contrast, the photos taken by P (programmed automatic exposure) blocks are often unsatisfactory and the effect is not the best. At this time, the photographer needs to manually adjust the exposure parameters of the equipment, that is, the exposure compensation EV (exposure value).

There are many ways to compensate and adjust the light, such as flash lamp, photographic lamp, off-mirror light and so on.

Compensation; Adjustment of aperture value and compensation of luminous flux parameters for exposure time. The above compensation methods, strictly speaking, should be classified as? Light compensation or exposure control? In the concept of. There is also the adjustment and compensation of EV unique to digital cameras. In the absence of other supplementary light sources, it is hard to compensate the flash light with external light sources, which often leaves obvious shadows on the background of the subject, and at the same time makes the quality of the subject dangerous and embarrassing. /span>。 Photographic lighting can create a good shooting effect, but it is often limited to the studio due to the limitations of conditions.

Reflective plates with soft light and supplementary light effect are widely used in portrait photography in small scenes, mostly for supplementary light on the main face, and their limitations are self-evident. The adjustment of aperture and shutter luminous flux parameters is often due to the need to consider the influence of depth of field and moving objects in the shooting process, which will have a feeling of being stretched in practical application. For popular digital cameras, the most common method is to adjust EV to achieve the purpose of exposure compensation. Most consumer digital cameras have them? 2.0EV adjustment range, high-grade DC can reach? 3.0EV. One of the indicators for testing a DC is its manual regulation function, and the regulation accuracy is also an important factor in EV regulation, generally 0.3 or 0.5. The smaller the grade difference, the more satisfying the photographer's creative intention. For beginners, exposure compensation is generally used for still life and scene shooting. This situation is suitable for you to adjust the parameters calmly, shoot many films with different compensation values, and choose the best works from them. Correctly adjust the EV value: use EV+ in typical underexposed scenes (objects have many bright areas, such as water surface, snow scene, sunrise and sunset scene, etc.). ), and use EV- in typical overexposed scenes (dark areas with many objects, such as dense forests, shadows and close-ups of black objects, etc.). ). In a nutshell, that is? White plus black minus, bright plus dark minus? .

It should be noted that the aperture/shutter parameters of the camera will change when the EV value is adjusted, regardless of whether the DC is in the P file or the S/A file: when the EV is adjusted in the P file, the aperture and shutter of the camera will be automatically adjusted; The fixed aperture under the adjustment of block A and EV will change the shutter speed; When the shutter is fixed under the S-stop and the EV adjustment is linked, the aperture size will change. However, these changes of aperture and shutter will not affect the exposure compensation effect after final imaging.

If you want to use the camera handy, it is essential to master the adjustment of ISO and exposure compensation.

These are all the knowledge that beginners need to know and remember. I believe that with this knowledge and corresponding photography skills, photography technology will certainly be able to go to a higher level.