What are the functions of aperture?

What are the three functions of the aperture?

(1) Adjust the lighting. This is the basic function of the aperture. When the aperture increases, the light intensity increases; When the aperture decreases, the light intensity decreases. It solves the exposure problem together with the shutter speed.

(2) Adjust and control the depth of field. This is the important role of aperture. Large aperture and small depth of field; Small aperture and large depth of field.

(3) affect the imaging quality. This is the function that the aperture is easily overlooked. Any lens has an aperture with the best imaging quality, that is, it is least affected by various aberrations. This aperture is commonly known as the best aperture. The exact position of the optimal aperture can be measured by using special instruments. Generally speaking, the best aperture is located at the position where the maximum aperture of the lens is reduced by about 2 ~ 3 steps. If it is greater than or smaller than the optimal aperture, lens aberrations such as spherical aberration, longitudinal chromatic aberration, coma, field curvature and astigmatism will increase, so try to use the optimal aperture when shooting to improve the imaging quality. The shape of the aperture will also affect the imaging quality. The closer the polygon is to the circle, the better the imaging quality. First, it is called "dog head" and "black head": low-end mass lens, including the head of low-end SLR camera.

What is the function of aperture?

Shutter is a component that controls the speed of light entering the camera, referred to as the speed of palace gate.

Aperture is a component that controls how much light enters the camera, and the aperture value is the amount of light.

Their relationship with photos is related to the brightness of the first photo and the color of the second photo.

If the shutter speed is slow and more light enters the camera, the photo will be bright, otherwise it will be dark.

The larger the aperture, the more light enters the camera, and the photo will be very bright, otherwise it will be very dark.

The larger the aperture, the smaller the depth of field, which means the background is blurred. The smaller the aperture, the greater the depth of field and the clearer the background. (Note: The aperture number is opposite to that on the camera. The larger the number, the smaller the aperture, and the smaller the number, the larger the aperture. )

The shutter speed and aperture will have different effects when they cooperate with each other.

What is the function of the aperture on the camera?

The aperture can adjust the luminous flux of the camera lens. When taking pictures under strong light, the aperture of the aperture should be reduced, otherwise it should be increased. Just like curtains, when the light is too strong, the curtains will be turned down, and when the light is dark, the curtains will be opened to make the room bright and suitable.

The size of the aperture is expressed by the aperture coefficient. The larger the aperture coefficient, the smaller the aperture. The smaller the aperture coefficient, the larger the aperture. For example, the aperture 8 is twice the aperture 1 1; Aperture 8 is half smaller than aperture 5.6.

Aperture can not only control the luminous flux of the lens, but also affect the depth of field. The so-called depth of field can be understood as the depth of the clear range of the scene image.

What are the advantages of a large aperture?

Does the landlord know what the aperture value represents? Aperture value is the ratio of incident aperture to focal length, not the real aperture size. This is also the reason why the smaller the aperture value, the larger the aperture. Constant aperture is not only powerful, but also requires high workmanship. Constant aperture does not mean constant aperture size, but constant aperture value. For example, 70-200 F2.8, the aperture is 25mm when the focal length is 70, but the aperture at the 200mm end is 7 1.4mm when the aperture is 2.8, which is a great challenge to the workmanship and design of the lens. Floating aperture does not need such a precise design, which is why zoom lenses with constant aperture, including lenses with constant aperture value of 4, are expensive. Pursuing 2.8 is really not a big deal, because Canon once had a lens similar to 50 1.0 in the last century, but in the zoom lens, 2.8 is the representative of luxury and fine workmanship. When making a large aperture lens, the lens is often different from the ordinary lens, which ensures the light input and imaging quality. With a large aperture, you can shoot in low light to make a shallow depth of field, and sometimes you have to get it. You want to take a beautiful picture, but it's a pity that there is no tripod or large aperture lens because of insufficient light. This is why many people choose the 2.8 zoom head.

What are the advantages of a large aperture?

Does the landlord know what the aperture value represents? Aperture value is the ratio of incident aperture to focal length, not the real aperture size. This is also the reason why the smaller the aperture value, the larger the aperture. Constant aperture is not only very powerful, but also requires high workmanship. Constant aperture does not mean constant aperture size, but constant aperture value. For example, 70-200 F2.8, the aperture is 25mm when the focal length is 70, but the aperture at the 200mm end is 7 1.4mm when the aperture is 2.8, which is a great challenge to the workmanship and design of the lens. Floating aperture does not need such a precise design, which is why zoom lenses with constant aperture, including lenses with constant aperture value of 4, are expensive. Pursuing 2.8 is really not a big deal, because Canon once had a lens similar to 50 1.0 in the last century, but in the zoom lens, 2.8 is the representative of luxury and fine workmanship. When making a large aperture lens, the lens is often different from the ordinary lens, which ensures the light input and imaging quality. With a large aperture, you can shoot in low light to make a shallow depth of field, and sometimes you have to get it. You want to take a beautiful picture, but it's a pity that there is no tripod or large aperture lens because of insufficient light. This is why many people choose the 0.8 zoom head.

What are the methods and techniques of aperture?

The smaller the aperture value, the larger the aperture, which can't be mistaken.

The subject needs to add an aperture in the shadow part to compensate for exposure.

The subject is close to white. If the picture scale is small and the environment is dark, you need to close the aperture.

The shooting environment is all white, such as snow scene, which needs aperture.

In fact, the above items are almost the same, because the camera metering is not based on the actual situation, and simply thinks that the average value of the whole picture is 18% gray level, so it should be compensated according to the actual situation.

The larger the aperture, the smaller the clearance range; Conversely, the smaller the aperture, the larger the clear range.

For specific applications, such as taking portraits, if the background is clear, your troops will be announced to seize the main position, so it is generally recommended to use a large aperture; When shooting scenery, you often have to shoot mountains, landscapes and water, and often close the aperture to achieve the picture effect.

Mastering these two knowledge points skillfully, your film should improve several levels. Let's go

What does aperture mean? What does aperture do?

Aperture: Simply put, it is to control the amount of incident light. The larger the aperture value, the less incident light.

Aperture can also control the depth of field effect of imaging. Generally, the smaller the aperture (that is, the larger the aperture value), the greater the depth of field.

The combination of aperture value and shutter speed is an important factor in the success or failure of a photo.

What is an aperture and what are its types?

The aperture is a very important parameter in photography. Before, our photography series from scratch also talked about aperture priority mode, but knowing aperture priority does not mean knowing what aperture is. In fact, the aperture is still very learned. Today, let's talk about what you have to know about aperture. What is the aperture? Simply put, the aperture is a parameter indicating the brightness of the lens. I think this is quite different from what everyone knows. Speaking of aperture, we should first introduce aperture. The hole in the aperture blade is the aperture. There is a device in the lens that can change its aperture by changing the position of the aperture blade. This aperture is the device that controls the light passing ability in the lens. For a lens, the larger the aperture, the greater the ability of light to pass through. However, we know that all lenses have their own focal lengths. For the same aperture, the longer the focal length, the narrower the viewing angle, and the smaller the total amount of light obtained in the viewing angle. Therefore, it only has good light passing ability, but due to the influence of telephoto, the total light input is small and the lens is not bright enough. Aperture value F= focal length/aperture focal length unchanged. The larger the aperture, the smaller the aperture value and the brighter the lens. The aperture is constant, the shorter the focal length, the smaller the aperture value and the brighter the lens. Therefore, the aperture is the most objective parameter to express the brightness of the lens. You need to know the aperture size, but in practice, aperture and aperture value are not the same concept. When asked about the exact parameters, aperture can be used as the abbreviation of aperture value. When communicating, the aperture often represents the size of the aperture. This involves an industry habit and can only be memorized. The larger the aperture, the smaller the aperture value. But when you ask what the aperture is, you usually ask what the aperture value is. Simply put, when used as an aperture value, F2.8 is greater than F8. Schematic diagram of aperture size A lens with a large aperture has good light transmittance and brightness, which is beneficial for photographers to take a view and focus on the camera. If the standard is F 1.0, the aperture value is one step every 1.4 times. The luminous flux of each aperture is 2 times different, because the aperture value is the ratio of the aperture diameter to the focal length, and the luminous flux is determined by the aperture area. The square of 1.445438+04 is exactly 2 times. On the other hand, according to the pinhole imaging principle of the same focal length, the smaller the aperture, the clearer the out-of-plane imaging of the focus, and the larger the aperture, the more blurred the out-of-plane imaging of the focus. In fact, the blur here is what is usually called background blur, which is what photographers call the depth of the scene. Different apertures produce different depth of field and have different uses. When shooting portraits, we often want to separate the portraits from the background. Shallow depth of field can achieve this goal, so you need to shoot with a large aperture. When shooting scenery, we want to get a clear picture from far to near, so we need a deep depth of field and shoot with a small aperture. Types of Aperture Fixed Aperture The simplest camera only has a fixed aperture with a round hole-Walter Hauser Aperture. The original variable aperture is just a series of circular holes of different sizes, arranged around a disk with a central axis; Rotating the disc can move the circular hole with appropriate size to the optical axis, thus controlling the aperture. John Vaught Hauser invented this kind of aperture in the middle of19th century. Mobile phones mostly use fixed aperture cat's eye aperture. The cat's eye aperture consists of a metal plate with an oval or diamond hole in the middle, which is divided into two parts. Two pieces of metal with semi-elliptical or semi-diamond holes are arranged in rows, and move relatively to form cat's eye holes. Cat's eye aperture is mostly used for simple cameras. Iris-shaped aperture is composed of a plurality of overlapping arc-shaped thin metal blades, and the size of the central circular hole can be changed by the clutch of the blades. Some cameras can change the aperture of the diaphragm by rotating the ring on the lens barrel, while others automatically change the aperture of the diaphragm by controlling the micro-motor through the microprocessor chip. Arc thin metal blades up to 18. The more arc-shaped thin metal blades, the closer the aperture is to a circle. By designing the shape of thin metal blades by computer, a nearly circular aperture can be obtained with only six thin metal blades. Instantaneous aperture The aperture of a SLR camera is an instantaneous aperture, which will be reduced to a predetermined size only when the shutter is opened. Usually the aperture is at the maximum position. SLR lenses use this kind of double shutter aperture. Some simple cameras have the function of shutter. Most of these double-shutter apertures are cat-eye apertures with double blades, which are different from simple cat-eye apertures: the double-shutter apertures are usually completely closed. Most large and medium-sized cameras are inter-mirror shutters. At the moment when the shutter is pressed, the double-blade aperture is opened to a predetermined aperture, and this is maintained ... >; & gt

What are the characteristics and uses of large aperture imaging and small aperture shooting?

Aperture affects exposure and plays a key role in depth of field.

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Large aperture can make the depth of field shallow and the focus clear, while other parts of the picture are relatively blurred, which is beneficial to highlight the main body and simplify the picture. This method is often used to attract the audience's attention to the subject when shooting portraits, still life and other subjects that need to highlight the subject.

In dark conditions, using a large aperture can also effectively improve the shutter speed. By improving iso, the shutter speed can be increased, thus improving the clarity of hand-held shooting, such as shooting concerts or occasionally shooting night scenes without tripod.

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Small aperture can increase the depth of field, so that the whole picture is not in the same focal plane from far to near clear. This method is often used to shoot landscapes without specific objects.

When shooting night scenes, on the basis of using tripod and cable, using small aperture can also get good results; Especially when shooting city lights, you can shoot stars with a smaller aperture.

What role does the aperture in a SLR camera play?

1, aperture priority is determined by you, shutter is determined by camera (automatic), time priority is determined by exposure time, and aperture is determined by camera (automatic).

2, the length of the lens, you may mean the appearance. But most of the time it refers to the length of the focal length. The number of 80-200MM on the lens refers to the zoom range, that is, the wide-angle focal length is 80MM and the telephoto end is 200MM. There are also lenses such as F3.5-6.3, which are the maximum aperture of the wide-angle end and the telephoto end respectively.

3. The focal length is the basic performance of the lens, which in principle refers to the distance from the center of the lens to the clear imaging surface. Generally, the longer the focal length, the smaller the imaging angle, which can make the distant scene bigger. The shorter the focal length, the larger the viewing angle and the wider the image, but the smaller the image of the distant scene.

4. The equivalent focal length within 35 is generally called a wide-angle lens, 35- 100 can be called a medium focal length, and 100 or more can be called a telephoto. Note that this is an artificial distinction, and there is no absolute standard when dividing. So my division is not necessarily accurate.

You can write a book if you want to start talking. If you don't know, I suggest you check online more. And you verbally say extra points, who knows?