Skills of choosing camera exposure mode

The first step in photography is to learn to use the camera in your hand. The following are my suggestions on choosing the camera exposure mode. Welcome to read!

Element 1: pore size

That is, the size of the lens aperture is usually expressed by the value of f, and f= lens focal length/lens effective aperture diameter. The smaller the f value, the larger the aperture and the more the unit luminous flux; The larger the F value, the smaller the aperture and the smaller the unit luminous flux. For example, the aperture f/ 1.8 is larger than f/5.6, and the luminous flux per unit time is more!

At the same time, the aperture is also an important factor affecting the depth of field. When other factors remain unchanged, the larger the aperture, the shallower the depth of field (the more obvious the blur effect); The smaller the aperture, the deeper the depth of field (wider the clear range).

A large aperture will produce blur, and a small aperture will easily produce starlight.

It can be seen that we can achieve two purposes by controlling the aperture, one is to control the amount of light entering, and the other is to control the depth of field effect.

Element 2: Shutter speed

Shutter speed is the exposure time, usually expressed as a fraction. The faster the speed, the shorter the exposure time and the less the luminous flux. The slower the speed, the longer the exposure time and the more luminous flux. For example, the shutter speed of 1/250s is faster than that of 1/30s, which means less time for passing light, so less light is obtained.

At the same time, the shutter speed also determines the capture effect of the camera. If we want to capture fast-moving objects, we should use high-speed shutters.

Element 3: ISO

Sensitivity (ISO), a concept handed down from the film period, represents the sensitivity of photosensitive materials to light. The higher the ISO, the more sensitive the photosensitive element is to light, and the less light is needed to achieve the same effect. The lower the ISO, the less sensitive the photosensitive element is to light, and more light is needed to achieve the same effect.

However, due to the limitation of the photosensitive elements of digital cameras, the picture is prone to noise under high ISO, so many photographers try to keep the ISO low when shooting to get a purer picture. The significance of ISO is to liberate the combination of aperture and shutter by improving the sensitivity of photosensitive elements under extreme light conditions.

You may wonder why the theme of the article is "exposure mode of camera", but you have to listen to these boring basic knowledge repeatedly. Don't disagree, this is the key to the problem.

First, P file and automatic file: suitable for beginners or lazy students who don't want to set up cameras.

In our common sense, we often think that P file is a novice file, which has some truth. Although P gear and automatic gear are slightly different, their principles are basically the same.

The fully automatic mode is a fool mode, and a set of modes is worked out by measuring the camera environment to ensure sufficient exposure. He will automatically choose white balance, aperture, shutter, ISO, flash and other means to promote the success of shooting, regardless of the shooting intention. P file is exposed by the camera according to the shooting environment, and combined with the exposure data stored internally, a relatively suitable exposure combination of aperture and shutter is generated. It looks a little spicy, but just pressing the shutter is all fool mode.

Of course, this mode is suitable for novices who know nothing, or "lazy" students who have no interest in camera settings. However, using this method does not mean that you are not enterprising. Some people think that the camera's program exposure function is already so powerful. Why not take advantage of this advantage and spend more time on improving your composition? Mobile phone photography is becoming more and more powerful. Isn't it all the principle of P file? There seems to be some truth.

Second, aperture priority mode: suitable for students who want to learn photography and know more about light.

As the name implies, the photographer first determines the shooting aperture according to his own needs, and then the camera gives a shutter speed according to your aperture to ensure reasonable exposure.

When using aperture priority mode, the first consideration is the change of depth of field, and different themes must be represented by different depth of field. For example, use a large aperture to blur the background of a person image:

Another example is that in landscape photographers, a small aperture is used to ensure sufficient depth of field:

It should be noted that when shooting with a small aperture, the corresponding shutter speed will also slow down, and a tripod is often needed to fix the camera.

Pay attention to the shutter speed even if you use aperture priority mode. The camera will only give a suggested shutter speed according to the luminous flux, so it can't carefully judge the shooting environment at that time, such as low light environment. The camera may give a speed lower than the safety shutter according to your aperture, which will cause hand shaking.

The reason why this is the most suitable exposure mode for students who have just learned photography is because it involves settings such as depth of field control and exposure combination. Every time you shoot, slowly exploring the relationship between these factors can help you better understand the exposure.

Third, shutter priority mode: used to create special photographic effects.

Contrary to the aperture priority mode, the shutter priority mode is to determine the shutter speed first, and then the camera gives the appropriate aperture size.

According to our previous understanding, taking pictures is to freeze a wonderful moment. Indeed, sometimes it is as simple as that. For example, when shooting a moving scene, you can only capture high-speed moving objects through the same high-speed shutter.

When we use high-speed shutter, we should pay attention to whether there is enough aperture or ISO to ensure exposure.

By controlling the shutter, you can not only freeze the moment, but also delay the time. For example, when shooting a running or racing car, use a slow shutter and move with the main body of the picture when shooting, which can form a focus-chasing effect of "clear main body and blurred background".

Or use a slow shutter and rotate the camera when shooting to extract a normal picture.

Manual mode: suitable for students who play photography seriously, have patience and perseverance.

At this point, I really started to play photography. To put it bluntly, photography is to play a game with the world with light and shadow, while manual mode is to let you master all the rules of the game in your own hands.

Send you a word, and you should deeply understand it in the future-there is no accurate exposure, only appropriate exposure. In fact, both the automatic mode and semi-automatic mode mentioned above involve the camera, and the camera helps you decide some parameter settings to make your picture "correct" and standard.

But sometimes we just need overexposed, underexposed and blurred images to express our images better. At this time, it can only be achieved by manual mode.

Since it is the digital age, there is basically no pressure in the manual mode. Now the camera's own metering function is very powerful, which is enough for shooting reference.

This silhouette is a good example. Through manual exposure, it is ensured that the background and foreground are lit up and the protagonist becomes a silhouette. If you leave it to the camera, it is likely that the exposure of the characters is accurate, but the background is too explosive.

Another use of manual mode is door B, which is the common long exposure. In the process of shooting for several minutes, the photographer needs to judge and control the picture independently, and try and adjust it repeatedly until the picture is properly exposed, which is beyond the judgment of the camera's own function.

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For beginners, how to understand the different exposure modes of the camera and how to make a reasonable choice can be started from these points:

(1) If you are afraid of trouble and don't want to spend too much time on parameter setting, please use the p file;

(2) If you want to learn photography, understand the relationship between camera and light and shadow, and control the depth of field, please use aperture first;

(3) If you need to control the exposure time, such as shooting high-speed motion and slow special effects, please use shutter priority mode.

(4) Of course, if you want to play photography seriously, you must learn to use the manual gear.