Aperture priority photography skill

Introduction: The quality of a photo is related to the exposure, that is to say, how much light should be passed for ccd to get a clear image. Exposure is related to light passing time (determined by shutter speed) and light passing area (determined by aperture size). The following are the aperture priority photography skills I brought to you, hoping to help you.

Shutter priority refers to the exposure value calculated by the automatic metering system of the machine, and then automatically determines how much aperture to use according to the shutter speed you choose. Aperture priority refers to the exposure value calculated by the automatic metering system of the machine, and then automatically decides how many shutters to use according to the aperture size you choose. Manual mode means that you specify the aperture size and shutter speed yourself.

The larger the aperture, the more light passes through per unit time, and vice versa. Aperture is generally expressed as the letter "F+ value", such as F5.6, F4, etc. It should be noted that the smaller the value, the larger the aperture. For example, F4 is larger than the aperture of F5.6, and the difference between two adjacent apertures is twice, which means F4 is twice as big as that passing through F5.6. Relatively speaking, the definition of shutter is very simple, that is, the time allowed for light to pass through the aperture is expressed by numerical values, such as 1/30 seconds, 1/60 seconds, etc. Similarly, the difference between two adjacent shutters is twice.

The combination of aperture and shutter forms exposure, which is not unique under certain exposure conditions. For example, the current normal exposure combination is F5.6 and 1/30 seconds. If the aperture is increased by one step, that is F4, the shutter value at this time will become 1/60, and this combination can also achieve normal exposure. Although different combinations can achieve the same exposure, the pictures taken have different effects.

The concept of "depth of field" is involved here. The so-called depth of field means that when the lens focuses on the subject, the subject and its scenery before and after have a clear range, which is called depth of field.

After understanding the basic concepts of aperture, shutter and depth of field, it is not difficult to use aperture limit or shutter first.

Aperture priority is to manually define the size of the aperture, and then use the camera's metering to obtain the corresponding shutter value. Because the aperture directly affects the depth of field, this mode is most widely used in ordinary shooting. When shooting portraits, we usually use large aperture and long focal length to blur the background and get a shallow depth of field, which can highlight the subject. At the same time, a larger aperture can also obtain a faster shutter value, thus improving the stability of hand-held shooting. When taking photos such as scenery, we often use a smaller aperture value, so that the range of depth of field is wider, which can make the distant and nearby scenery clear, which is also applicable when shooting night scenes.

Contrary to aperture priority, shutter priority is to obtain aperture value through camera metering when the shutter is defined manually. Shutter priority is mostly used to shoot moving objects, especially sports shooting. Many friends find that when shooting moving objects, the subject is often blurred, mostly because the shutter speed is not fast enough. In this case, you can use the shutter priority mode, roughly determine a shutter value, and then shoot. And the motion of the object is generally regular, then the shutter value can also be roughly estimated. For example, the shutter speed for photographing pedestrians is only1125 seconds, while it takes11000 seconds for photographing falling water droplets.

In the case of aperture priority, we can easily control the depth of field by changing the aperture size, while in the case of shutter priority, using different apertures can achieve good shooting results for moving objects. Both should be used flexibly to meet our shooting needs in different situations.

When shooting moving objects, the shutter is generally preferred, because the photo will be blurred if the shutter is slow. For example, it is enough to shoot pedestrians1100 seconds, and shoot falling water droplets11000 seconds. Artistic, of course.

Unlike technology, nothing is absolute. If you want the afterimage behind the car, you can set a slower shutter to show the movement. If you shoot MM, if you want to blur the background, you must use a large aperture, which is generally preferred.

Aperture, shutter and depth of field:

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 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. No matter for traditional cameras or digital cameras, the aperture is represented by the letter "F", and the aperture in the center of the aperture is represented by the corresponding value, that is, the "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 "increasing the aperture" usually refers to narrowing 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 river" or solidified water droplets, using slow shutter and high (fast) shutter respectively. 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, with different shutter and aperture combinations,

They achieve the same exposure, but their suitable shooting environment and shooting effect are different. 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:

In the above paragraph, we mentioned the concept of "depth of field". Reasonable use of the effect of depth of field can play an 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.

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 more light enters.

The less, the camera will extend the exposure time of the shutter. Aperture priority is generally represented by "a" on digital cameras.

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. Shutter priority on digital cameras is generally represented by "S".

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. Manual mode is generally represented by "m" on digital cameras.

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