Three elements of exposure

Beginners of photography must know the aperture, shutter and sensitivity of the camera. Only by mastering the application of these three basic parameters can they take photos with normal exposure.

The aperture is equivalent to a person's pupil. When we are in strong sunlight, our pupils will contract, reducing the amount of light entering. When we are in the dark, our pupils will dilate and increase the amount of light. When we turn up the aperture, it means expanding the pupil and letting more light into the camera. When we lower the aperture, it means narrowing the pupil and reducing the amount of light entering the camera.

The larger the aperture, the greater the amount of light entering. When we open the aperture to the maximum, it is equivalent to expanding the human pupil to the maximum and letting the light enter the camera to the maximum.

The smaller the aperture, the less light enters. When the aperture is opened to the minimum, it is equivalent to narrowing the pupil to the minimum, so that light can only enter the camera through a small hole, which minimizes the entry of light.

Simply put, the larger the aperture, the higher the blur degree, and the smaller the aperture, the weaker the blur degree. You can refer to my other article about the blur effect of aperture: background blur.

We can understand the focal plane as the range around which we can clearly see the focus.

We can notice that the larger the aperture, the more obvious the blurring effect, because the range of the focal plane is very narrow, and the farther away from the focal plane, the stronger the blurring effect. Therefore, when taking a double photo and a group photo, if you want to shoot with a large aperture, you need to put the subject on the same focal plane. Otherwise, things close to the focus and away from the focus plane will become blurred.

Therefore, when we take a group photo, we usually narrow the aperture to increase the range of the focal plane. The smaller the aperture, the larger the range of the focal plane. Even things that are not so close to the focus can be clearly displayed on the focal plane.

Shutters are used to adjust the time when light enters the camera.

A shutter speed of 1s means that light enters the camera for only one second, and a shutter speed of 30/ 1s means that light enters the camera for 30/1s..

The longer the shutter time and the longer the light entering time, the easier it is for the photo to be overexposed. The shorter the shutter time, the shorter the light entry time, and the easier it is for the photo to be underexposed. In low light environment, if the aperture is still not exposed to the maximum value correctly, the shutter speed can be increased appropriately to allow more time for light to enter the camera. In strong light environment, the shutter speed can be reduced appropriately to reduce the time when light can enter the camera.

High-speed shutter is often used to capture snapshots and record the instantaneous state of objects. It is often used in sports events, children's photography, shooting water droplets and other scenes where objects are in motion.

Low-speed shutter is often used to record the motion track of objects, and it is often used to shoot light tracks, star tracks and silky running water.

Sensitivity is to increase or decrease the sensitivity of the camera to light. The higher the sensitivity, the easier it is to overexpose the picture, and the lower the sensitivity, the easier it is to underexpose the picture.

In the weak light environment, when the aperture is opened to the maximum and the shutter speed cannot be lower than the safe shutter speed, the camera can be exposed normally by improving the sensitivity. But don't increase your sensitivity easily. The disadvantage of improving sensitivity is that it will produce noise. The higher the sensitivity, the more noise, the more obvious; The lower the sensitivity, the better the picture texture.

Aperture, shutter and sensitivity complement each other. Only when all three parameters are adjusted in place can a normal exposure photo be taken. Getting started with photography is not difficult. Take out your camera and shoot a few more times, and you will soon get used to it.