What affects the size of the diaphragm. Likbez: what is the aperture and shutter speed and what depends on them. The effect of the diaphragm on the bokeh
What is a diaphragm? In the photo.
Short definition
Aperture is a structure inside the lens, consisting of thin petals. Opening and closing the diaphragm can be controlled 1) the amount of light passing through the lens; 2) angle of refraction of light rays (depth of field).
You can see the aperture very well with fast fixed lenses, such as for example. If you want to see the aperture blades of your lens, then turn on your camera, select the manual mode, select the aperture value 14 and click on the preview button for the depth of field, which is usually located near the lens. At the same time, if you look into the front lens, then you should see how the petals move when the button is pressed. If you still don’t know how to set the manual mode on the camera, change the aperture or don’t know where the button for previewing the depth of field is located, then you should read the manual.
Aperture and focus blur
For simplicity, if the aperture index doubles, the hyperfocal distance is divided into two. Thus, if the aperture index is divided by two, then the blur size is doubled.
Opening and Depth of Field
In photography, if you want to get out of the annoying “auto” mode to take a photo with creativity and personality, there is one concept that is needed: exposure.Here we deepen the opening of the diaphragm. The purpose of this article is to make clear what openness is and how it affects your photographs and, in particular, the depth of field and exposure. To make it simple, the diaphragm is a device consisting of metal plates.
1. Aperture and brightness of the photo. Exposition.
The more the aperture is open, the more light hits the image sensor and the brighter the photo. The more the aperture is closed, the less light gets on the image sensor and the darker the photo. Thus, aperture is one of two ways to influence the brightness of a photograph. The second way is to change the shutter speed, or the amount of time when the camera shutter is open and light enters the matrix.
The diaphragm plates form a more or less large hole, mechanically regulating the light on the sensor. Since we never repeat enough if the diaphragm is closed, the diameter of the hole will be smaller and therefore the light passing through the device will be smaller. On the contrary, the larger the aperture and the brighter the image.
For the exhibition, we can summarize the following: - a small number \u003d a large aperture \u003d brighter - a large figure \u003d a small aperture \u003d less light. As you can see in this example, the larger the aperture opens, the brighter the image. Depth of field is the area of \u200b\u200byour photo that will be sharp or “in focus”.
2. Aperture and depth of field.
The size of the aperture determines the angle of refraction of the rays of light. Depth of field, one of the most important characteristics in photography, depends on the latter. The larger the aperture, the smaller the depth of field in the photograph. The smaller the aperture, the greater the depth of field in the photograph.
If you take a portrait, it will be interesting to open to bring out a person in the background, whereas if you photograph a landscape, it is better to close it so as not to “blur” the background. To summarize: - a small number \u003d a large aperture \u003d a small and a large part of a blurred image - a large figure \u003d a small aperture \u003d a very deep and most part of a sharp image.
As you can see in this example, the closer the aperture, the larger the area of \u200b\u200bsharpness. In addition, if we compare this, we note that the opening of the aperture is not the only factor affecting the depth of field, that is, also the focal length. Moreover, you decrease the focal length or, in addition, you move away from the depth of field increases.
When shooting a classic portrait, a large aperture is used. What for? Then, to emphasize the most important thing in the photo - the person’s face, and leave everything else in the blurry background so as not to distract. Depth of field in portrait photography can be up to half a centimeter, this is enough. Although in this case, the tip of the nose and ears are no longer in focus, so you should very carefully choose the focus point. When you photograph a person, the focus is always on the eyes.
Opening Priority Mode
In conclusion, there are two lines that you need to write on a post-it or a tattoo on the arm
The principle of the camera. In addition to several structural details that differ in type, today's cameras work on the same principle and consist of the following basic elements.When the shutter button is pressed, the shutter opens so that light passes through the lens, which will provide a sharp image of an object that will be photographed on film or a digital sensor. The amount of incoming light is determined by the shutter closing time and the aperture size of the aperture. At the end of the exposure, the shutter resumes its initial closed position.
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How to adjust the aperture.
Stop and aperture values. To make it easier for you to shoot.
About what a diaphragm is.
The aperture can be adjusted as you like. In order to make it easier to change the aperture, you should use special steps for the diaphragm of the camera - the foot. The concept of stops is also used along with exposure, but we will talk about this next time. Each stop of the diaphragm transmits half less or half more light than the next.
The goal is an optical system on the front of the camera, which consists of lenses whose purpose is to form an image on a sensitive surface, film or sensor, the choice of which is necessary, since it is responsible for quality. It can be fixed or interchangeable, its main feature is its focal length , which determines the magnification and field of view observed through the lens. More precisely, the focal length is the distance in millimeters separating the film or sensor from the optical center of the lens when the focus is infinite.
Each stop has its own diaphragm value. Usually they look like this:
In the photo above - the most common stops of the diaphragm. There are lenses with aperture larger (f / 1.4, f.1.2) and smaller (f / 27, f / 32), but this is rare.
If you are trying to adjust the aperture on your camera (if you are unsure how to do this, be sure to read the manual for using the camera), then you will certainly notice that the aperture changes in specific values, but the numbers may differ. Between full stops there are still other numbers. This is because on modern digital cameras, the aperture can be adjusted much more accurately than is done with full stops. Usually in the camera menu you can choose whether you want to adjust the aperture using full stops or not.
The longer the focal length, the closer the lens is to the plane on which the image is formed, the wider the field of view and the longer the focal length, the smaller the field of view. Focal length is commonly called zoom. In practice, this is usually called a 50 mm camera, and devices with a smaller focal length are called wide angles, the rest are called telephoto lenses. The minimum and maximum focal lengths are recorded in front of the lens. These distances are completely different between the digital camera and the digital camera because the size of the digital camera sensor is relatively small.
| Full feet | f / 4.0 | f / 5.6 | f / 8.0 | f / 11 | f / 16 | f / 22 | ||||||||||
| 1/2 foot | f / 4.0 | f / 4.5 | f / 5.6 | f / 6.7 | f / 8.0 | f / 9.5 | f / 11 | f / 13 | f / 16 | f / 19 | f / 22 | |||||
| 1/3 foot | f / 4.0 | f / 4,5 | f / 5.0 | f / 5.6 | f / 6.3 | f / 7.1 | f / 8.0 | f / 9.0 | f / 10 | f / 11 | f / 13 | f / 14 | f / 16 | f / 18 | f / 20 | f / 22 |
Aperture values \u200b\u200bcan be confusing at first, since a larger value indicates a small aperture and vice versa. For example, 4.0 indicates a larger aperture than f / 11.
The smaller the aperture value (the larger the aperture itself), the smaller the depth of field.
Diaphragm - This is an adjustable hole (from Greek - a partition), with which you can control the depth of field, aperture and exposure. Different lenses have a different aperture, which consists of several sickle-shaped metal petals that rotate when the aperture is closed, the more the petals, the more pleasant bokeh. Usually found from three or more petals, a pleasant bokeh is obtained already at seven, eight petal aperture. A larger number of petals creates a more circular bokeh with a closed aperture, which makes the image more attractive. The five-blade aperture is also often used in both photo and video shooting, creating a pentagonal-rhomboid shape in this bokeh. It is customary to denote the diaphragm as “f / number”, the larger the number, for example f / 22, the stronger the aperture is closed and vice versa, the smaller the number f / 1.4, the stronger the aperture is open. With an open aperture, more light enters the film or matrix, but if we start to close the aperture, reducing the hole, the amount of light that is projected from the subject to the film (matrix) decreases. Thus, by opening and closing the diaphragm, we control aperture.
- Close the aperture - f / 1.4, f / 2, f / 2.8, f / 4 and up to f / 22
- Open the aperture - f / 22, f / 16, f / 11, f / 8 and up to f / 1.4
It should be noted that by closing the aperture, we reduce the aperture ratio, this affects the exposure, so that the exposure remains correct, the shutter speed should be reduced, in modern cameras this action is performed automatically, except for manual mode (manual) .Thus, we control with the aperture exposure. To increase the hole, and with it the amount of light entering the matrix, you need to reduce the number (for example, f / 1.4), and vice versa, to reduce the hole you need to increase the number (for example, f / 22), at this point novice photographers are confused . There is a special ring on the lenses to adjust the aperture; on modern SLR cameras, the aperture is controlled from the camera.
Photo No. 1
Aperture, shutter and depth of field
The lenses are then very close to the sensor. For this reason, we usually find a match with the classic 35 mm that characterizes silver. The diaphragm is a mechanism present on the lens whose function is similar to that of the iris. It consists of thin strips that overlap, which allows you to adjust the amount of light passing through the lens. Its meaning is called openness. Therefore, the larger the aperture value, the closer the aperture. The shutter can be located in the center of the lens or directly in front of the film.
A photographer can also use the aperture to achieve various artistic goals, because with the help of the aperture you can control the depth of field and always get different results by shooting the same objects. With an open aperture (f / 1.4), the depth of field will be minimal, and the stronger we close the aperture (f / 1.4, f / 2, f / 2.8, etc.), the more we increase the radius of depth of field. On the left is a photograph with an aperture of f / 1.8, and on the right is f / 5 that when the hole is reduced, the depth of field increases.
Photo No. 2
It consists of mutually overlapping metal plates whose purpose is to transmit light or not. When the shutter button is pressed, the shutter opens and closes. Typically, digital cameras offer four exposure adjustment modes.
Depth of field is the distance between the nearest point and the farthest point where the camera provides a sharp image. It is unevenly distributed on both sides of the focusing distance. twice as wide as the back than in front of the subject. Depth of field depends on.
In a film camera, an image is formed on a transparent plastic film on which a photosensitive layer formed from silver grains is applied. Chemically activated by light, a latent image is formed in the chamber. The image thus obtained is called negative, since the tones of the photographed subject are reversed. In the development lab, the image is transferred to paper after exposure under a magnifier. It is then detected by the action of a chemical bath called a developer, which darkens the activated grains of silver and the remaining colorless grains, and then the paper passes through the stop bath to block the action of the developer. in order to avoid any further action of light on non-activated grains, another chemical bath will take care of their elimination, this is a fixative, then the paper is washed to remove all residues of the chemical. Three photosensitive layers are superimposed on each other and separated by color filters.
Using the aperture, you can blur the background and highlight any object, thereby hiding some of the flaws, because the background is not always beautiful. When the aperture is as wide as possible, objects lose sharpness, as well as when they are very closed, it is better to test the lens itself, since there are different wide-angle, portrait, telephoto lenses and each has a different aperture diameter. A fast portrait lens with an f / 1.2 - f / 16 aperture differs in technical characteristics of the aperture characteristics from a wide-angle f / 4 - f / 22 lens. In photography, aperture like shutter speed and light sensitivity (ISO) is of great importance. And if you understand the principle of the aperture, you can safely turn off the auto mode and switch to manual shooting mode that will expand your creative capabilities. About fotomtv.
There are various film carriers, but all of them have a common characteristic of their sensitivity, when the sensitivity doubles, the amount of required light is divided into two. On digital cameras, the film is replaced by a sensor. This data is then stored on the device data medium, most often represented by a removable memory card. To facilitate archiving of images, they are compressed. This compression mode can be set before shooting and determine the number of images that can be saved on the card.
Opening a photographic lens determines the amount of light passing through the lens to project onto the photosensitive cell of the camera. Depending on the size of the aperture of the photographic lens, the amount of transmitted light is checked. The smaller the number, the less light or, if required, the larger the aperture. Depending on the size of the aperture used, a shutter speed should be used to sufficiently expose the photosensor to reaction. This is often called opening speed.
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Lens aperture
The diaphragm is an adjustable hole (from Greek - a partition), with which you can control the depth of field, aperture and exposure. Different lenses have a different aperture, which consists of several sickle-shaped metal petals, which
It seems simple, but this combination cannot be used simply by quick calculation, because these adjustments have a direct effect on the image you want to take. The size of the aperture determines the details and clarity of photographing or depth of field. For example, hole 8, which allows a lot of light, quickly activates the sensors of the photosensitive cell without leaving time for distant parts to print.
In principle, the higher the value, the greater the depth of field, and therefore more attention will be focused on photography. The opening speed is also a value that cannot always be randomly selected. You can use one for a stationary object, but for photographing an athlete this can only be done at a shutter speed, otherwise the image will be blurred. Therefore, a compromise between depth of field and speed is often necessary.
