Setting up the camera. Shutter speed and aperture, ISO, focal length. What are aperture, shutter speed and ISO? What is shutter speed and aperture in the camera

This article covers such basic concepts as shutter speed and aperture... There is also a table of exposures, using which it is easy to choose the correct aperture value at a given shutter speed and vice versa, which correspond to the correct exposure.

The picture above is the shutter speed, and the right is the aperture value. In most cameras, exposure can be adjusted by changing both the aperture and shutter speed. In the first case, the intensity of the light passing through the lens, or the illumination of the photographic material, is regulated, in the second, the time of exposure of the light to the photosensitive emulsion layer of the photographic material (if the camera is a film camera). However, by changing the shutter speed and aperture, you can not only ensure the correct exposure, but also control the depth of field and movement of the subject.

First, a few general definitions: Excerpt- the time interval during which the light acts on the area of ​​the photosensitive material to impart a certain exposure to it. Exposure time- the time interval during which the shutter of the camera is open to obtain a frame (exposure of the frame), that is, during which light affects the photosensitive material within the entire image field. Diaphragm- a camera lens device that allows you to adjust the relative aperture, that is, to change the lens aperture - the ratio of the brightness of the optical image of the photographed object to the brightness of the object itself, as well as to set the required depth of field.

This figure shows 8-blade aperture reduction. The left is completely open.

Shutter speed scale

Many modern cameras use a standard scale of shutter speeds in fractions of a second, and for short shutter speeds (less than 1 second), the numerator is omitted, and the shutter speed is described by the denominator:

• 8000 (1/8000 s)
• 4000 (1/4000 s)
• 2000 (1/2000 c)
• 1000 (1/1000 s)
• 500 (1/500 s)
• 250 (1/250 s)
• 125 (1/125 s)
• 60 (1/60 s)
• 30 (1/30 s)
• 15 (1/15 s)
• 8 (1/8 s)
• 4 (1/4 s)
• 2 (1/2 s)

Aperture values

Standard values ​​of aperture (relative aperture) are based on increasing or decreasing the illumination of an optical image by a factor of two: 1 / 0.7; 1/1; 1 / 1.4; 1/2; 1 / 2.8; 1/4; 1 / 5.6; 1/8; 1/11; 1/16; 1/22; 1/32; 1/45; 1/64. The numbers indicated on the lens or set on the camera (5,6; 8; 11 ..) are called aperture numbers.

Exposure control

The aperture control ring is calibrated so that when the aperture is closed to the next value, the film illumination is halved. The shutter speed head is calibrated in the same way, i.e. the ratio of 2: 1 is maintained between adjacent shutter speeds. Referring to the exposure table below, you can find that for the given lighting conditions, the correct exposure is obtained at a shutter speed of 1/60 s and an aperture of 1: 5.6. Having set these values ​​on the camera, we get a correctly exposed transparency. But it turns out that a properly exposed transparency can be obtained at a shutter speed of 1/125 s and aperture of 1: 4 or 1/30 s and 1: 8, i.e. with any equivalent combination.

Shutter speed to aperture ratio table

The ratio between shutter speed and aperture value corresponding to the correct exposure. The above diagram shows that for each value of the “closing” of the aperture, the duration of the exposure, i. E. shutter speed must be doubled to obtain a constant exposure value. The choice of one of the possible combinations of aperture-shutter speed should be made taking into account the nature of the subject, as well as the author's interpretation of the scene. The fact is that the quality of the transfer of any kind of movement of the object will depend on the choice of shutter speed, and the depth of the field of focus will depend on the choice of aperture.

Controlling motion transmission and depth of field

For the optimal choice of shutter speed, you should analyze how the movement of the subject will be captured in the picture. Suppose, for example, that the subject of the photograph is a car moving across the field of view at a speed of about 100 km / h and the photograph is taken at a shutter speed of 1/30 s. During the time during which the shutter curtains are open, the car will travel almost 1m, and as a result, its image on the film will be blurred. If you reduce the shutter speed to 1 / 500th of a second, the car will move only 5 cm, and the resulting image will be sharper. The need to use low shutter speeds arises in sports photography, when it is necessary to "freeze" the movement. Slow shutter speeds have to be used when the camera is moving quickly, for example, when shooting from a moving car or train. And even in cases where shooting is done with a stationary camera, it is better to photograph with a slow shutter speed, in order to exclude the inevitable slight movement of the camera when the shutter release button is pressed. Changing the aperture during photography primarily affects the depth of field, that is, the distance between the objects closest to the camera and the objects farthest from it, within which the details of the scene appear equally sharp in the picture. The smaller the effective aperture of the lens, the deeper the depth of field. When photographing many subjects, a large depth of field, i. E. very sharp reproduction of details both in the foreground and in the background is extremely important. For example, in landscape photography, the photographer can build his composition so that the sharpness in the picture is a cover of flowers or other interesting details that are close to the camera, while at the same time the background is clearly transferred. Using a small aperture will ensure that both will be as sharp as possible. In cases where it is required to clearly convey only the main subject of the shooting and separate it from the background, which interferes with the perception of the main detail, or to highlight any detail of the image, a small depth of field is needed. A shallow depth of field is achieved by using a large lens aperture.

It follows from the above that it is practically impossible to simultaneously "stop" the movement of the subject and obtain a large depth of sharp imaged space, since in order to obtain a normally exposed frame to fulfill the first requirement, a fast shutter speed and, therefore, a large aperture value are required, and to complete the second - small aperture values ​​and, therefore, long shutter speeds. In such a situation, you have to compromise by using medium shutter speeds and apertures, and none of the requirements are fully met.

What is shutter speed, aperture, ISO sensitivity. Introduction to exposure

Despite the fact that this word may seem unfamiliar and even intimidating to some, we are faced with exposure every time we photograph something. because exposure is the total luminous flux that falls on the matrix during the exposure time.

If the matrix receives too little light flux, then such a frame will turn out to be too dark, that is, underexposed or underexposed. Here is an example of such a frame:

Comments, as they say, are superfluous. The first desire that arises when viewing this photo is that you want to lighten it! But, trying to add brightness, we will inevitably face a loss of quality. In dark places (shadows), the matrix received such a small luminous flux that information about the color of these fragments is partially or completely absent.

If we try to lighten an underexposed image, we will get guaranteed distortion of shades in the shadows, as well as a high level of color noise.

On the contrary, if the matrix received too much light flux, then the photo turns out to be too light, that is, overexposed or overexposed. Peresvet is even more evil than lack of light. If an underexposed image can be somehow corrected in Adobe Photoshop, then an overexposed image is much more difficult to save, and in many cases it is completely impossible. When there is insufficient light, we have a lack of information about dark areas. Nevertheless, the information is there. There is simply no information about the color in the overexposed area - the processing program perceives it simply as a completely white area of ​​the picture. And no matter how perfect the image processing algorithms are, none of them will be able to "come up" with those details that were lost during overexposure.

Below is an example of an overexposed shot.

The picture shows that the hull of the yacht has lost all the details and has become just a white speck. No matter how we try to darken it, the lost parts won't come back.

These two examples show that when photographing, you need to somehow maintain a balance between overexposure and under-light, that is, to ensure the correct exposure. In this case, the photo will be balanced in highlights and shadows and will look its best.

How to ensure correct exposure?

The exposure is set by three parameters:

Excerpt

Diaphragm

ISO sensitivity

Excerpt- this is the time interval when the camera shutter is open and the matrix receives a luminous flux. The longer the shutter speed, the more light flux the matrix receives, the brighter the photo is.

Diaphragm- This is a mechanical "pupil" of the lens, which can open and close, thereby changing the intensity of the light flux entering the matrix. With an open diaphragm (dilated pupil), the luminous flux is maximum, with a closed diaphragm (constricted pupil), it is minimal.

ISO sensitivity- the degree of susceptibility of the matrix to light. Changing this parameter allows the matrix not to be "blinded" by daylight (for this you need to set a low sensitivity) and not to suffer "night blindness" in a dark room and to take shots in it without a flash (for this you need to increase the sensitivity).

These three parameters set the exposure.

If we draw a parallel between these seemingly complicated things and our daily life, I offer a very clear example. Suppose we have a glass and we need to fill it with tap water. This can be done in two ways - turn on the pressure more powerful and fill the glass in 1 second, or draw water in a thin stream for a minute. In this case, a glass is a matrix cell, water is a luminous flux, a tap is a diaphragm (the wider the hole, the stronger the flux). And the time it takes to fill the glass is aging. But if we are unable to fill the glass in the allotted time, the only way to comply with all the "formalities" is to reduce the volume of the glass. A glass of 2 times smaller volume will be filled 2 times faster. Thus, the volume of a glass is the reciprocal of the sensitivity. Less volume (faster glass is filled) - higher sensitivity (you can shoot with a shorter shutter speed).

So, what needs to be done to fill the glass up to the rib, that is, the photo is correctly exposed?

The exposure must first be measured

In modern cameras, all these three parameters can be set automatically. In most cases, the automation works flawlessly, so many do not even think about exhibiting something and changing something. But in a number of cases, the automation does not work correctly and we start looking for the cause ... After reading the instructions for the camera, we find out that automatic exposure metering operates according to one of several algorithms. Each of them is "sharpened" for different lighting conditions. Here are the main types of metering algorithm ...

• Integral (matrix) metering
• Partial and spot metering
• Center-weighted metering

What is the difference between them and which mode is better to use? We look at the table ...

	Integral (matrix) metering	Partial, spot metering	Center-weighted metering
Measurement area	Exposure data is taken from the entire area of ​​the matrix and averaged. Based on this "arithmetic mean", the shutter speed and aperture are set.	Exposure data is taken only from a small area in the center of the frame (with partial metering, the area is larger, with spot metering, less). The illumination at the edges of the frame has no effect on the calculation of the exposure.	Exposure data is taken from the entire frame, but the area in the center has the greatest weight. The closer a point is to the edge of the frame, the less its effect on the final exposure.
When is it better to use	The main mode for shooting when the illumination in the frame is more or less uniform and there are no objects that are strongly "knocked out" of the general tone.	When the key subject is very different in its illumination from the general background and it should be well developed. An example is a portrait of a person in dark clothing against a dark background.	As a rule, the result does not differ much from the integral measurement. However, when shooting high-contrast scenes, more attention is paid to the exposure of the center of the frame.
When not to use	If the brightness of a small object differs significantly from the brightness of the background, there is a risk that the subject will be either overexposed or underexposed. In this case, it is better to use partial or spot metering.	It is not known what fell into the small measuring area - white snow or dark branches. The result is an almost unpredictable exposure level when shooting "colorful" subjects.	There are no obvious restrictions, you need to look at the situation. It is important to remember that sometimes it is impossible to work both light and dark areas at the same time. If the difference in illumination between objects is too large, then we use additional lighting (for a portrait) or shoot in HDR (landscape).

After metering the exposure, the automatic equipment of the device sets the exposure pair - shutter speed and aperture. Numbers flash in the camera's viewfinder, for example:

This means that the shutter speed is 1/250 seconds, the aperture is 8. The camera is ready to shoot, we just have to press the shutter button!

The exposure can be corrected ...

It so happens that the automatic exposure metering is wrong and the photo has a slight overexposure or under-light. In this case, you can make a correction to the metering operation and reshoot the scene so that the next frame is normally exposed. But here's the question - how to determine if there is an error in the exposure in the captured frame? After all, on a small LCD screen, often with not ideal color reproduction, there is not much you can see! And here a wonderful function comes to our aid - viewing the histogram.

A histogram is a graph showing the distribution of brightness in a photo.

Here is an example of a photograph and its histogram:

In this case, you can see that the histogram "rests" on the left edge - this means that there are underexposed objects in the photo that look on the verge of blackness. At the same time, you can see that there is some free space to the right of the graph. To get rid of the lack of light, let's try to adjust the exposure by + 1 / 3EV (this is equivalent to increasing the shutter speed "by 1 click of the wheel", that is, by 1/3 stop).

To enter exposure compensation, we need to find a button on the camera with the following icon:

Keeping this button pressed, turn the control wheel, or press the joystick (different devices have it differently). The screen will display a slider that you can move left or right:

If you move the slider to the right, the picture will be lighter (positive exposure compensation), if to the left - darker (negative exposure compensation).

Here's a version of the previous shot taken with positive exposure compensation.

We see that the picture has lightened a little, the elaboration of shadows on it has improved. At the same time, the histogram moved slightly to the right. If you make a big correction, then the shadows will be worked out even better, but the clouds will be overexposed, that is, they will lose shades and go into whiteness. In this case, the histogram will shift even more to the right and will be "cut off" from the side of the highlights. Thus, we derive an important rule:

Ideally, the histogram should not appear clipped on either the left or right. If the histogram is cropped on the left, there are underexposed areas in the photo and there is a loss of information in the shadows. If the histogram is cropped on the right, then there is a loss of shades in the light areas in the photo.

Sometimes a situation arises when the histogram rests on both the right and left - in this case, there is a simultaneous loss of detail in the shadows and highlights in the image.

Questions and tasks for self-control

1. What types of metering does your camera have?
2. Experiment with metering modes. Which subjects are better with integral metering, which ones are better with spot or partial metering?
3. Find out how your camera activates the exposure compensation function.
4. Take pictures of the same scene with positive and negative exposure compensation, follow the changes in the histogram.

I finally realized that why you need a shutter speed, aperture and ISO should be written as clearly as possible, in simple words. There are too many questions from students and readers, it is easier to give a link.

Excerpt

So, excerpt. This is the time it takes for the light to fall on the matrix. It is measured in seconds and fractions of a second. Usually, the camera can set the shutter speed from 30 seconds to 1/4000 of a second, for older models up to 1/8000.

"One 8000th of a second" is very little, the so-called "very short shutter speed" - you can freeze the wings of a hummingbird in the picture or catch a shell almost frozen in the air flying out of the muzzle of a tank (if the reaction is enough to pull the trigger in time). The shorter this time, the shorter the shutter speed, the less light will pass into the camera, onto the matrix.

“Thirty seconds” is a lot, that is, “very long exposure” - when there are no cars on the night street, but only traces of their headlights, this is just a few seconds of exposure.

Using the Bulb mode or a remote control cable, you can give a shutter speed of tens of minutes. For example, to take a photo of the sky with the stars smeared in lines.

People who are standing and posing for you, you can shoot for 1/30 of a second, if they are not frozen but still behave calmly, it is better to shoot for 1/100 of a second. Children who run actively by 1/300 of a second. I would shoot a hockey player at a match or a basketball player for 1 / 250-1 / 800 seconds to freeze. A cyclist flying over a track, a snowboarder jumping, or a rally car flying over a hillock, 1/1000 of a second or less. And here is a frame taken in the subway with a shutter speed of 1/5 of a second - you can see that motionless people are sharp, and moving people are smeared.

At the same time, if I want to shoot a clear car, so that it has smeared rotating discs and a background blurred from movement in the back, I will set a shutter speed of the order of 1/40 - 1/60 and I will drive the car "in the scope" of the camera, and in the necessary moment I will smoothly press the trigger without stopping the movement. This is called a guided survey. So it is possible, but what does not move itself move and also shoot. Here's an example of a shot recently taken with a Sony A7 at a shutter speed of 1 / 60th of a second on the Garden Ring:

On a lens with a focal length of 50 millimeters, it is better to shoot at a shutter speed of 1/50 or shorter (1 / 100-> 1/1000 ....), and if there are more millimeters, then reduce the shutter speed accordingly. For example, at 100-400mm it is worth photographing from 1/100 to 1/400, depending on the focal length (general formula 1 / F where F = the focal length of the lens). This is the case. The reason is simple - the lens is shaking in your hands, and by choosing a shutter speed that is too slow, you blur the picture. It becomes blurry not because the lens is bad, but because you are shooting wrong.

Diaphragm

Have you seen how a person's pupils narrow in the sun, and dilate in the dark? Essentially, it is the diaphragm in the eye that works.

Adjusts the amount of light that enters the camera through the lens onto the sensor. The more it is folded (closed), the less light penetrates. The diaphragm should be closed if there is more light than you need. But this is only half the battle.

Simultaneously, the aperture adjusts the depth of field. “Depth of field” is not the same as sharpness, that is, I'm not talking about the clarity of the picture, and not about whether the hair and fabric in a photograph of a person is sharp, whether every lint is visible. It's about whether the background is smeared behind it or not. The wider the aperture is, the shallower the depth of field. On lenses like f / 1.4 or f / 1.2, it can be sooo small - literally millimeters. That is, in the portrait, the eyes will still be sharp, and the ears and the tip of the nose will already be blurred.

Yes, and the depth of field is not only about the background - everything outside of it is blurred, both in front and behind.

The closest analogy from life is how a person squints. When the eyelids are strongly compressed, the same depth of field increases, and what a person saw before that was blurred, due to some peculiarities of aiming the eye at a distance, or optical defects of the eye itself, it becomes clear.

Depth of field is measured in meters (centimeters and millimeters) - the more the aperture is closed, the further away from you the blur will start.

If you close the aperture too much (up to f / 22, for example) along with the increased depth of field, the picture will begin to lose clarity. You will get the depth of sharp space "from me to the horizon", but you will no longer be able to make out even on clear objects small details - capillaries on leaves, antennae near a flower and an inscription in small print on a fence, because it is difficult for light to penetrate through a tightly closed opening in the lens , it starts to mix.

ISO

The sensitivity of the sensor to light. The higher the value, the better the sensor sees in the dark, the less light it needs to get a similar picture.

If we take analogies from anatomy, then it is like the sensitivity of the eye: there are those who see in the dark better than others, and if they were robots, one could say about them, they have “higher ISO”.

The higher the sensitivity, the more grain and noise in the photo, the more sharpness (not depth of field!) And detail drops. If at ISO 100 every hair is visible in a portrait of a person, then at ISO 25600 they will all be smeared into mush, the photo will be something like a picture where the hair was painted with brush strokes [and sprinkled with sand].

The main thing here is ... not to be afraid! The value of the shot is not in the sharpness of the hair. As practice has shown, if you take photos from any more or less modern camera, be it Canon 550D or Nikon D3100, not to mention more modern and older models, taken at ISO 6400 and printed on A4 format, you will see that the picture is still very much nothing... All this noise, which is very clearly visible at high zoom, is completely lost when printing or reducing the size of the photo.

Here's what the test image looks like, unprocessed, taken at ISO 12800 on a Canon 1D X:

More examples can be found in the post "

In this article, we will understand how manual camera settings affect the quality of the image. Any novice photographer wants to understand the capabilities of their camera in order to use them to create spectacular shots and make the process of photography completely manageable.

Let's see how the following settings will affect the image quality:

Learning to choose a focal length

What is focal length? If you already have a camera, but did not have time to get acquainted with its many settings, and you still shoot in automatic mode, then this simulator will teach you how to use your technique to 100%. Let's take a look at what a focal length is and how its choice affects the final result.

Focal length is the distance from the front lens to the photosensitive element, i.e. matrices. Measured in millimeters. The choice of focal length depends on whether you want to shoot close-up, medium or general. And the degree of background blur and perspective will also depend on the choice of focal length.

Set the distance from the camera to the subject on the simulator to 2 meters, and now change the focal length. The simulator simulates a zoom lens with a focal length of 18-55 mm. Experiment and you will see that the shorter the focal length, the more space fits into the frame, and increasing the focal length brings distant objects closer.

You can set the desired focal length in this camera by adjusting the optical ZOOM or changing the lens.

Types of lenses

Lenses come with a fixed focal length (the so-called "fix") and with a variable focal length (the so-called "zooms" from the word zoom, zoom in). You can set the desired focal length in this camera by adjusting the optical ZOOM or changing the lens.

Wide angle lenses

Lenses with a focal length of less than 35mm are called wide-angle lenses. With their help, it is convenient to shoot nature and architecture, groups of people in a room, when there is no way to move away.

• The angle of view along the diagonal of the frame is 60 degrees or more.
• A wide-angle lens can capture a wide panorama.
• The depth of field of panoramic images is large, i.e. everything in the background seems to be very well worked out.
• Distortion occurs when shooting at close range with a wide-angle lens.

Standard (supplied) lenses

Standard lenses are suitable for all types of shooting. The focal length for most of these lenses ranges from 45 to 55 mm.

Long focal lenses

• Lenses with a focal length of 80 mm or more and an angle of view from 30 degrees.
• Maximizes the subject of photography, allows you to capture it in close-up, well-developed.
• The proportions when shooting with a telephoto lens are not distorted.

How else does the choice of focal length affect the shot?

Perspective

In the picture, close people and objects appear larger, and distant ones appear smaller. When using a wide-angle lens, this effect is enhanced, that is, close objects are reproduced with emphasis large, and distant objects are very small.

When working with long-focus lenses, the opposite effect is observed, that is, the distant parts of the plot are reproduced somewhat more, and the close parts are slightly less than it is perceived by the naked human eye.

Depth of field

Depth of field is the distance within which objects are in focus. If it is small, we get a blurred background (and foreground, if any), then they speak of "shallow depth of field", and if this distance is large, they speak of "large depth of field".

Depth of field depends on various factors, including focal length. With a large focal length, we get a shallower depth of field, that is, a blurry background.

Setting shutter speed and aperture

As you know, the quality of the picture depends on how much light passes through the camera lens and hits the matrix. The luminous flux intensity is regulated by two mechanisms:

• the size of the hole through which light passes (diaphragm);
• the time for which the path of passage of the light flux is open (exposure).

Setting aperture for taking pictures

Diaphragm is a mechanism that sets the size of the hole in the lens through which light passes. The diaphragm should react to light like a pupil that dilates in darkness and contracts in bright light. The diaphragm is adjusted according to the same principle: in dim light, the diaphragm has to be opened so that as much light as possible gets on the sensor. And if the photo is taken on a bright sunny day, then the diaphragm closes. The diaphragm can also be compared to a window opening - the larger the window, the more light enters the room.

Generally accepted aperture values indicate the ratio of the diameter of the lens inlet to the focal length and are written like this: F / 2.8, F / 5.6, F / 11, or like this: F 2.8, F 5.6, F 11.

Aperture values ​​are one of the factors that affect the depth of field.

Effect of aperture values ​​on depth of field

Setting the shutter speed for still images

Excerpt is the time for which the camera shutter is open. The shutter speed, like the aperture, controls the intensity of light falling on the photosensitive element. Imagine a room where the wallpaper burns out in the light. If you close the window with shutters, the burnout process can be stopped.

In 1826, it took eight hours exposure in bright sunlight to obtain the first-ever photograph "View from the Window", taken on a tin plate covered with a thin layer of asphalt.

The first photograph in the world, "View from the window", 1826

In the early stages of the development of photography, the shutter speed at which the photographer opened the lens cover was tens of minutes.

In our time, exposure is usually tenths, hundredths and even thousandths of a second. Fast shutter speeds allow you to take high-quality pictures without using a tripod. When shooting handheld, the shutter speed should not exceed 1/80 of a second - otherwise, the frame may blur due to hand shake.

Sometimes slow shutter speeds are used to create interesting visual effects:

How shutter speed and aperture settings affect exposure

Exposure is the amount of light from the light sensor. It is formed by two parameters - shutter speed and aperture - which are also called "exposure coupler". In modern amateur cameras, exposure metering and calculation of the exposure pair are automated. In professional cameras, automatic exposure metering is disabled (fully and partially).

Try to work on the camera simulator in manual mode and set such a pair of shutter speed and aperture to get a high-quality picture.

ISO setting. How to choose ISO for photography

Another parameter that affects the photo is ISO. How to work with ISO settings and what to use them for?

ISO is the camera's sensitivity to light. The quality of the picture directly depends on how much light hits the matrix. ISO is one of three factors that determine exposure, along with aperture and shutter speed. The choice of ISO depends on the nature of the lighting during shooting.

For example, if you are photographing in low light, you can raise the ISO value, this will reduce the shutter speed and will not blur the photo.

Try adjusting the ISO settings on a simulator that has lighting set like in a room. Increase the ISO and click on the "Take Photo" button until you see a smiling emoticon.

The ISO scale usually starts with a value of 100, and each subsequent value changes twice, up to the limits of the camera's capabilities: 100, 200, 400, 800, 1600….

ISO setting affects noise

As you increase the ISO, you will find that the higher the ISO value, the more noise you get in your photo.

Therefore, for the best quality, try to shoot always try to shoot in good lighting and use the lowest possible ISO. Then you will get great sharp photos without noise.

Conclusions. What ISO settings to use in what cases

ISO 100: Photos will come out great. Suitable for shooting in daylight.

ISO 200 - 400: For slightly less lighting, such as in the shade, cloudy weather, or indoors if it is brightly lit.

ISO 400 - 800: Suitable for indoor shooting, flash can be used.

ISO 800-1600: Suitable for indoor shooting where the flash cannot be used or is prohibited.

ISO 1600-3200: This range is useful in low light conditions when using a tripod is difficult. Significant digital noise appears in the image.

ISO 3200+: This range is reserved for extremely low light conditions, but the noise is very high and the image is too grainy.

Instructions

The term "diaphragm" comes from the Greek word for "septum", its other name is aperture. The diaphragm is a special device built into the lens to regulate the diameter of the hole that allows light to enter the matrix. The ratio of the diameter of the lens aperture to the focal length of the aperture.

F stands for f-number, which is the reciprocal of the lens aperture. Changing F by one stop, we get a 1.4-fold change in the diaphragm opening diameter. And the amount of light falling on the matrix will change 2 times.

The smaller the aperture, the deeper the depth of field of the imaged area, i.e. an area in sharp focus around the subject. You can set the required aperture, depending on the model of the camera, manually through the camera menu by rotating the aperture ring on the lens or the control wheel on the camera body.

The lower the F number, the larger the aperture, and, the diameter of the lens opening becomes wider and more light enters the sensor. The maximum aperture is f1.4, f2.8, etc. For a 50mm lens, the depth of field will be maximum at f22, and at f1.8, the sharpness will be small. For example, when shooting, in order to get a clear face and a blurred background, the aperture should be set to a small f2.8. If the diaphragm is clamped on the contrary, i.e. set a larger aperture value, then the predominant part of the frame will be in focus.

The length of time during which the light rays hit the matrix is ​​called the shutter speed. The shutter secures it. Aperture and shutter speed together with exposure pair. The increase in sensitivity is inversely proportional to the exposure, i.e. if the sensitivity is doubled, the exposure should also be halved. To measure shutter speed, fractions of a second are used: 1/30, 1/60, 1/125 or 1/250 s.

For moving subjects, a fast shutter speed should be used to avoid wiggling. To calculate the required shutter speed, you need to know at what focal length you will be shooting. For example, the lens is 24-105 mm, it is extended by half - about 80 mm. And since the maximum shutter speed should not be more than a value inversely proportional to the focal length, the shutter speed should be set no longer than 1/80 s. Short shutter speeds are used to "freeze" movement: a bird's flight, drops falling, an athlete's running, etc.

For shooting at night or at dusk, a slow shutter speed is better. It will help to correctly expose the frame. When shooting with slow shutter speeds, there is a high likelihood of blurring the frame, in this case it is worth using optical stabilization or a tripod. Such an exposure will allow you to shoot interesting scenes - a "fiery trail" during evening and night shooting of moving cars.

When shooting water, the shutter speed is very important. With a short shutter speed, the water will resemble glass. When shooting slow rivers and streams, it is best to use shutter speeds between 1/30 s and 1/125 s. Rushing streams or waves crashing against rocks should be shot at a short shutter speed of 1/1000 s, because it will allow you to work out fine splashes in detail. For shooting fountains and waterfalls, a long exposure is suitable - it will allow you to convey the movement of water.