Difference of pore size

Regarding the difference of aperture size, simply speaking, the larger the aperture is, the more light enters, and the brighter the photos will be, which is suitable for use in places with general or bad light, but exposure will occur if the aperture is adjusted too much! The smaller the aperture, the less light enters and the darker the photo, which is suitable for use in places with too strong light. But if the aperture is too small, the photo will be black! Let me take a closer look at their differences.

Difference of pore size

Aperture is a device used to control the amount of light entering the photosensitive surface of the fuselage through the lens, usually in the lens. We use the f value to represent the aperture size. For the manufactured lens, we can't change the diameter of the lens at will, but we can control the luminous flux of the lens by adding a polygon or circular aperture grating with variable area inside the lens. This device is called an aperture.

The aperture is composed of several blades inside the lens, which form a circle to control the luminous flux of the lens. F value (aperture value) is usually used to replace the aperture value, and the specific numerical definition is the ratio of the focal length of the lens to the diameter of the circle formed by the aperture blade (that is, the aperture size). For example, when the focal length of the lens is 50mm and the aperture diameter is 35mm, the aperture value is 1.4. According to the definition of aperture value, the larger the aperture value, the smaller the aperture, that is, the smaller the circle surrounded by aperture blades and the smaller the luminous flux. The aperture values of two adjacent steps are two times different. That is to say, the aperture area of two adjacent gears is twice different, that is, the aperture diameter is twice different from the root sign. According to the definition of aperture value, the difference between two adjacent apertures is twice the root sign, which is about 1.4 times. The standard aperture value is usually:1.0-1.4-2.0-2.8-4.0-5.6-8.0-1-6-22-32, which usually appears in the aperture ring of old lenses. Nowadays, cameras can usually use the aperture of 1/2 or 1/3, so there will be a nonstandard aperture value of 7. 1. On the lens of a camera, the aperture value is usually explained in the form of 1:f value, such as 1:2.8. From the definition of aperture value, we can know that the maximum aperture value of this lens is 2.8, that is, its maximum aperture diameter relative to the focal length of the lens is 1:2.8. For example, Canon's EF 100 mm 1: 2.8L is the USM macro.

Difference of pore size

The quality of the photos we usually take is related to the exposure, that is to say, how much light does it take 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).

Shutter priority means that the exposure value is calculated by the automatic metering system of the machine, and then the aperture is automatically determined 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.

When you have requirements for the shutter, the shutter is the first choice. If you shoot a high-speed moving object, the shutter is definitely faster, so you control the shutter and the camera controls the aperture. It should be noted that the adjustable range of the aperture is smaller than that of the shutter, so when using the shutter for the first time, if the shutter is adjusted too fast or too slow, the camera will not be exposed correctly.

Aperture priority is the opposite. Shutter priority is to manually define the shutter value of exposure, and the camera will determine the aperture size according to this shutter value.

Set the camera dial to S, or set the exposure mode to S in the menu, which is the shutter priority function.

Shutter priority is mostly used to shoot moving objects, such as sports, moving vehicles, waterfalls, flying objects, fireworks, water droplets and so on.

Many friends find that when shooting moving objects, the subject is often blurred, mostly because the shutter 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.

Let's learn about the relationship between focal length, shooting distance and aperture.

Background blur is a common and frequently used phenomenon in portrait photography, which is closely related to the focal length of the lens used, the brightness (aperture value) of the aperture and the shooting distance (the distance from the camera to the subject). The longer the focal length is, the easier it is to blur the background when the aperture value of the lens is constant. Of course, if the focal length is the same, the brighter the aperture, the easier it is to produce blur effect. In addition, the degree of background blur will change with the change of shooting distance. The shorter the shooting distance, the closer it is to shooting, and the greater the blur effect. Therefore, if you want to get a sharp blur effect, you should choose a lens with shorter shooting distance, brighter aperture and longer focal length. Only when taking portrait photography, first determine the focal length of the lens, and then fix the shooting distance after the composition is completed. Therefore, while mastering the basic principle of blur, we also need to master the relationship between lens focal length and shooting distance.

The larger the aperture, such as 1.4, 1.8, 2.0, usually the background is blurred and only the subject is clear. The ones with small aperture, such as F8+06, have good scenery and clear distant places, but the shutter requirements are different. The large aperture is higher than the shutter speed, and the small aperture shutter speed is much lower. That's all I have to say about the difference in aperture size.

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