Dependence of shutter speed on aperture and ISO. What is aperture, shutter speed and ISO? What is exposure

The Free Foto Help .ru project is the basics of photography for beginners. It was conceived as a free help to a person who for the first time decided to understand digital cameras, the basics of photography, frame composition and post-production processing of photos - therefore, all articles and lessons are written in a simple and understandable language, with minimal use of specific professional photography terms.

If you decide to study the art of photography, but don't know where to start - take the first step into the world of professional photography with Free Foto Help .ru. After studying photography lessons and other site materials, you will learn the basics of photography, get acquainted with the terminology of professional photographers, find out how a SLR camera differs from a compact one and why professional photographers prefer digital SLRs, as well as much more that will allow you to make a quick and easy start in knowledge photography as art.

Where to learn photography: photography school, photo courses or free photography lessons?

How to learn to take pictures beautifully? With this question, most beginner photographers are looking for photography courses or photography schools. Do not rush to look for a photography school or photography courses - you can learn photography easily, simply and for free!

Photography lessons for everyone

In free photography lessons, I will tell you about the basics of photography in a simple and accessible language, without complex terms and calculations, using simple examples that do not require special knowledge.

Don't understand what the photographers are talking about?

To understand what professional photographers are talking or writing about when you are studying reviews about cameras and other photographic equipment or chatting on photo forums, a concise dictionary of photo terms and colloquial expressions of professional photographers will help you

How to set up your camera correctly

Why is the photo lighter or darker than it should be? In those cases of photography, when the lighting conditions are different from the usual, it is quite difficult to get the correct exposure in automatic mode.

To set up the camera in manual mode, the photographer needs to set only three parameters. Examples of setting the camera in manual mode

How to learn
take pictures with a reflex camera

After looking through the instructions for his first digital SLR, a novice photographer comes to the conclusion that it is hardly possible to learn how to take pictures with a SLR camera yourself. And the search for suitable photography courses begins. Did you know that learning to take pictures with a SLR is no more difficult than with any other camera?

Free books for beginner photographers

Free books on the theory and practice of photography in PDF format will not only allow you to quickly and easily learn how to photograph, but also help you decide on the choice and purchase of a camera, lenses, flashes, lighting for a photo studio and other photographic equipment

Photography as art

Do you want to learn how to capture the attention of the viewer and make him look at your photos for a long time? If you dream of becoming a professional fine art photographer in the near future, start learning the art of photography today.

All about SLR cameras

Do you want to buy a SLR camera, but you are embarrassed by ignorance of the technical intricacies of photographic equipment? You have already studied a thousand reviews about SLR cameras, but still can't decide on the choice of your first SLR? Get advice from experienced photographers

How to choose a camera

Many novice photographers compare the number of different camera settings, their technical characteristics, but they still cannot choose a specific camera model.

How to test a camera before buying

Do not know how to check the camera before buying? The suggested procedure for testing a digital camera before purchase is applicable to any digital camera, including SLRs.

How to choose a camera lens

The choice of lens for a camera is perhaps more important than the choice of the camera itself.
Usually, the question of whether to buy a SLR camera with a lens or not arises even before buying your first DSLR, and answering it often turns out to be even more difficult than choosing a camera.

How to make a budget photo studio

Lighting and fixtures for your own photo studio can be made by hand, while the quality of studio portraits taken in such a budget photo studio will be no worse than in a rented professional photo studio

Light as a photographer's material

The very technology of obtaining a photographic image allows the photographer to automatically create the illusion of three-dimensionality on flat photography, however, on condition that the photographer perceives light not as something taken for granted, but as a tool and material from which the photograph is obtained, the same material as clay for a potter or a sound for a musician

Why does a DSLR shoot worse than a compact?

Owning a digital SLR has always been the privilege of professional photographers. But today, even a novice photographer can afford to buy a SLR camera. Are you sure that any SLR camera photographs better than a soap box?

Virtual camera with examples of settings in M ​​mode

A virtual camera simulator (simulator for a beginner photographer) allows you to adjust almost all the parameters of a real DSLR under different shooting conditions. Examples of virtual camera settings in manual mode M will allow you to learn how to quickly correct your own photography mistakes

Getting ready for holiday photography!

Preparing for the holiday, we usually focus on preparing a festive dinner, choosing and wrapping gifts, and completely forget to prepare for a photo shoot!

That is why very few photos you take during the holidays remain as delightful and exciting a year after the photo was taken.

You might think that it's all about practice - you need to photograph the holidays more and someday you will get great pictures that will awaken your memories many years later, with the same force as if the holiday was just yesterday.

Cold photography tips

The instructions for the camera say that it cannot take pictures at sub-zero temperatures! Five rules of photography in winter, observing which you will not spoil your camera even in thirty degrees of frost

Family holiday photography

Holiday photography of the whole family is not an easy task, especially if the family is large and the holiday was a success - no one will wait for you for a long time, so instead of joyful smiles, it is very likely to get faces tired of waiting for photography. And photography advice from your dear relatives is another reason to prepare for a family photo shoot in advance.

Photo video studio "Bekar" - all kinds of professional photo video shooting!

Let me remind you that in the previous article we considered the main types and genres of photography in terms of professional demand, creative development and commercial potential with one goal: to narrow the boundaries of the photo space to one or two genres that you can choose as a professional. And if you are a beginner photographer or want to become one, and even if you are just fond of photography, but not always happy with the pictures, believe me, it makes sense to read the first article of this course ().

In this part of the course, you will learn how a photo or video image is formed, why light is the only main visual means, how and what light affects in an image, what parameters of a photo camera and with what consequences allow you to adjust the intensity of light.

For photo and video shooting professionals, this information will definitely seem banal, so I want to remind you: the course " Photography as a profession"is aimed primarily at beginners, at people who are not burdened with knowledge in this area. Therefore, to begin with, let's look at what basic elements a photo or video camera consists of and how a photo or video is formed in these devices. video image. So: despite the presence of a huge number of parts, electronics and mechanisms, two nodes are responsible for image formation in a photo and video camera: optical system and sensor.

It is by passing through the lens and falling on the matrix that the light flux forms an image. What, in principle, is the term " photo" — light painting, or light painting technique, or acquisition and storage of an image using a photosensitive material or a photosensitive matrix. In general, I would like to say that everything that we see around us is formed by a stream of light reflected from those objects that we look at. In humans, the visual organ - the eye, consists of the lens (the same optical system) and the retina, which acts as a light-sensitive sensor. Both human vision and a photo/video camera work on the same principle: the light flux, reflected from objects, passes through the optical system, is converted, enters the matrix and is fixed.

At the same time, it is no secret to anyone that if you go with your eyes open, but into a completely dark room, we are unlikely to see anything. And if you take a photo in a completely dark room, it will turn out completely black.

Therefore, we can say with full confidence that light, in any of its manifestations, is the only main visual means of photo and cinema art. And it is on the quantity and quality of the light flux that, probably, 90% of the quality of the photograph itself depends. In addition to the fact that the light flux forms a photo or video image as such, thanks to the light, shadows are formed on the subjects of shooting, which, in addition to solving some specific artistic tasks, give the photograph or film frame, first of all, volume. For example: in the first photo we observe a complete absence of shadows, and if this picture is not compared with the second, it seems that everything is fine...

In the second photo, shadows are visible on the model's face, and it is already clear that this shot looks more voluminous compared to the first.

The third shot in a primitive form demonstrates the use of a shadow in solving some kind of artistic problem.

The importance of light and shadow in photography is greater than in cinema. Firstly, because in cinema what cannot be said with light and shadow can be said with dialogue or frame dynamics, and secondly, cinema allows you to tell a story throughout the entire duration of the film, and photography in this sense is limited to one moment. In one picture, the photographer needs to convey to the viewer all the information that corresponds to his worldview and artistic intent.

The meaning of light and shadow, the study of light schemes and light characteristics of optics is dedicated to the section of our website " ", and now we will continue to talk about what are the adjustable parameters of a photo video camera and, most importantly, how they can influence the amount of light that forms an image.

So, once again you picked up the camera, and tormented by doubt in which mode you will shoot (in manual or automatic), choose automatic. If this photoshoot is very important for you, and you are not completely sure of your knowledge, you have made the right choice. But if you absolutely have nowhere to hurry and you do not bear any financial responsibility for these photos to the customer, switch to manual mode. Especially given the theme of the course "Photography as a profession" and the generally recognized trend professional photographers work in manual mode. So: in addition to the presence or absence of a shadow, the intensity of light affects the overall exposure of the image. According to photo slang, the photo may turn out to be either underexposed,

Underexposed photo

or overexposed.

Overexposed photo

In the first case, there was little light entering the matrix, and in the second case, there was too much. At the same time, a huge amount of photographic details (folds of clothing, wrinkles on the face, some other elements) almost irretrievably disappear in the bright colors of the overexposed image, and in the dark tones of the underexposed image. Looking ahead a little, I want to immediately note the fact that underexposure is easier to correct and bring into proper form with software than overexposure. That is, strongly overexposed photo unequivocally moves to the basket, and some details can be pulled out from the underlit one.

How can you adjust the exposure manually?

Three options: diaphragm, excerpt and ISO.

What is a diaphragm?

Diaphragm- this is an element of the optical system (lens), which allows, by reducing or increasing the relative aperture, to regulate the amount of incoming light.

The operation algorithm is simple: smaller hole - less light, larger hole - more light. In this case, you just need to remember that the smaller the numerical value, the more relative aperture. That is, at aperture 1.4, the aperture will be larger than at aperture 16.

Arithmetic lovers can find information on why aperture is expressed in such fractional values, and can even draw a parallel between aperture values ​​and the lunar cycle. You don't need it. I recently had to attend a master class by a cinematographer from some regular Moscow film academy, and so he began his lecture precisely with an explanation of how many steps, in what proportion the aperture and shutter speed are regulated, what is the relationship between these values ​​​​and the system linear coordinates and a lot of other things he said, without answering the question of one of the listeners, what exactly in the movie image these parameters influence. It took me exactly 10 minutes.

Returning to our topic: in order to avoid overexposure in the frame, the aperture can be covered by increasing the numerical value, and in case of insufficient lighting, slightly opened by decreasing the numerical value.

Exposure-balanced photography

What to do if the aperture is fully open, and the picture is underexposed (dark)?

Help comes excerpt. Unlike aperture, which controls the intensity of light in quantitative terms, shutter speed controls the amount of light in terms of time. For example, if the water tap in the first case is slightly opened and left open for 20 seconds, the same amount of water will pour out of it as if we open it completely for 5 seconds.

After passing through the lens, the beam of light hits a mirror (or curtain) located directly in the camera in front of the matrix. When we press the shutter button, we raise the mirror, allowing light to hit the light sensor.

It is the time when the mirror allows light to hit the matrix is ​​called exposure. And as a time characteristic, it is measured in seconds. The longer the mirror is open, the more light reaches the sensor. Unlike the aperture, the relationship between the shutter speed and the amount of light is direct. That is, for example, a shutter speed value of 1/250 means that the mirror will be open within 1/250 of a second, and a value of 5 means that the mirror will be open for 5 seconds. Returning to the question what to do? If the aperture is fully open and there is not enough light, you can increase the shutter speed. And vice versa: if there is too much light and the aperture is completely closed, you need to reduce the shutter speed.

We have one more parameter left, which most often allows us to take a photo with a normal exposure from an underexposed (underexposed) image. it ISO, or photosensitivity matrices. Previously, this parameter was directly related to a photo or film and depended on the quality of the photosensitive layer, but now, given that the role of the film is performed by the matrix, this parameter was retained by it. And he became software. The photo matrix has a certain sensitivity range, and by changing the ISO value, you allow the matrix to absorb the amount of light that corresponds to this ISO value. This value is measured in units, from 100 to several thousand, depending on the camera model. If you increase the ISO with equal shutter speed and aperture, you will see how the photo becomes brighter, and vice versa - when the ISO is reduced, the sensitivity of the matrix decreases, the picture becomes darker.

Photographers resort to adjusting ISO upwards as a last resort. The main drawback of increasing the ISO sensitivity of the matrix is ​​that the so-called artifacts appear in the photographs in the form of digital noise.

It is clear that you can partially get rid of noise by software, sometimes the presence of noise can be justified by artistic intent and give the image some kind of vintage look, but still, 200 units are considered the standard value for the matrix sensitivity. And digital noise can also be added programmatically to achieve a creative intent, but only on a high-quality, normally exposed image.

And only if you cannot, for reasons that I will discuss later, change the aperture and shutter speed settings, and you do not currently have the opportunity to use additional lighting, only then it makes sense to increase the ISO.

Now about the main thing in order: what does changing the aperture in one direction or another affect, besides the amount of incoming light? First of all, to the depth of field, or as they say in a professional environment, to IPIG — depth of field. In addition to the distance to the subject and the focal length of the lens, it is the aperture value that affects the depth of field of the imaged space. And this dependence is directly proportional. Under other appropriate conditions, opening the aperture reduces the depth of field, closing the aperture increases the depth of field. If you want only the subject to be in focus, and all other details of the picture before and after it to be artistically blurred, in addition to changing the distance to the subject, you need to open the aperture as much as possible.

In this case, the exposure of the picture must be corrected by shutter speed, ISO, or an additional light source. The same is true for large depth of field. In order for the greatest amount of image detail along the optical axis to remain in sharpness, the aperture should be closed as much as possible, and the excess or lack of light is also compensated by shutter speed, ISO or an additional light source.

This photo shooting mode, in which the aperture value is paramount, is called aperture priority shooting. In practice, it can be used manually, as I mentioned above, or automatically. All modern SLR cameras have a marking on the command dial Av, indicating exactly shooting with aperture priority in automatic mode. In this case, you just need to set the required aperture value yourself, and the shutter speed will be adjusted based on the metering values. Not enough light - the shutter speed will increase, a lot of light - the shutter speed will decrease. The aperture value will remain as you set it.

Next: what effect does changing the shutter speed have on photography? First of all, on the sharpness of the depicted objects. The slower the shutter speed, the more likely it is to take a clear, not blurry picture. The slower the shutter speed, the blurrier the picture becomes. Even if there is an inanimate static object in the lens. In this case, the blurring of the photo gives you a non-absolutely static position - a barely noticeable reeling of the body, a barely noticeable shaking of the hands.

The following conclusion suggests itself: firstly, if you need to shoot dynamic scenes, sports events, moving objects, the shutter speed in this case should be minimal in order to avoid blurring. Only if your artistic intent does not imply the presence of a so-called trail in the frame behind a moving object. Secondly, when shooting the night sky, night streets and everything that can be photographed at night without the use of additional lighting, you need to set a slow shutter speed, but at the same time use a tripod. A tripod eliminates the possibility of camera vibration, and thereby reduces the number of blurry objects in the frame to a minimum.

Similar to aperture priority mode, there is shutter priority mode. It can also be manual or automatic (marked with the icon on the camera control dial). TV) and is used on the same principle: for you at the moment the aperture value does not matter and you do not need to control the depth of field? Then, depending on the specific task, you set the required shutter speed and if in manual mode, then you expose the frame with the aperture yourself, and if you turn on the Tv mode, the camera will control the aperture depending on the exposure meter.

I already talked about the negative impact of changing the ISO earlier, so let's summarize:

and aperture, shutter speed, and ISO allow you to change the overall exposure of the frame, but at the same time Aperture allows you to control the depth of field, shutter speed affects image clarity, a ISO adds digital noise to a photo.

If you want to become a professional photographer, don't forget: in photography, light is the main visual means, so by correctly adjusting the intensity of the light flux with aperture, shutter speed or ISO, you can create exposure-balanced photographs while maintaining all the necessary details in light and dark colors and without compromising the artistic intent of the image.

Take pictures of everyone, everything and always!

Articles

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

While this word may seem unfamiliar and even intimidating to some, we encounter exposure every time we take a picture of something. because exposure is the total luminous flux that hits the matrix during the exposure time.

If the matrix got too little light, 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 unnecessary. The first desire that arises when viewing this photo is to lighten it up! But, trying to add brightness, we will inevitably encounter 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.

When trying to lighten up an underexposed image, we get a 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 luminous flux, then the photo turns out to be too light, that is, overexposed or overexposed. Overexposure is an even greater evil than underexposure. 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 completely impossible. With underlight, we have a lack of information about dark areas. However, the information is there. There is simply no information about the color in the overexposed area - the processing program perceives it simply as an absolutely white section of the picture. And no matter how perfect the image processing algorithms are, none of them will be able to "invent" those details that were lost during overexposure.

Below is an example of an overexposed image.

The picture shows that the hull of the yacht has lost all the details and has become just a white speck. As we will not try to darken it, the lost details will not return back.

These two examples show that when taking photographs, you need to somehow strike a balance between overexposure and underexposure, that is, ensure the correct exposure. In this case, the photo will be balanced in highlights and shadows and will look its best.

How to ensure the correct exposure?

The exposure is set by three parameters:

Excerpt

Diaphragm

ISO sensitivity

Excerpt- this is the time period when the camera shutter is open and the matrix receives a light 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 falling on the matrix. When the aperture is open (dilated pupil), the luminous flux is maximum, when the aperture is closed (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 low sensitivity) and not to suffer from "night blindness" in a dark room and take shots without a flash in it (for this you need to increase the sensitivity).

These three parameters set the exposure.

If we draw a parallel between these seemingly complex things and our everyday 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 powerfully 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 faucet is a diaphragm (the wider the hole, the stronger the flow). And the time it takes to fill the glass is exposure. But if we fail 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 twice as small will fill up twice as fast. Thus, the glass volume is the reciprocal of the sensitivity. Less volume (glass fills faster) - higher sensitivity (you can shoot with a faster shutter speed).

So, what needs to be done so that the glass is filled "up to the rim", that is, the photo is correctly exposed?

Exposure must be measured first

In modern cameras, all this trinity of parameters can be set automatically. In most cases, automation works flawlessly, so many do not even think about setting something up and changing something. But in a number of cases, the automation does not work correctly and we begin to look for the cause ... After reading the instructions for the camera, we find out that automatic metering operates according to one of several algorithms. Each of them is "sharpened" for different lighting conditions. Here are the main types of exposure 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? Let's 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", 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, the area is smaller). Illumination at the edges of the frame has no effect on exposure calculation	Exposure data is taken from the entire frame, but the area in the center has the most weight. The closer a point is to the edge of the frame, the less of an effect it has on the final exposure.
When is the best time to apply	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" from the overall tone.	When the key object in its illumination is very different from the general background and it must be well developed. An example is a portrait of a man in dark clothes against a dark background.	As a rule, according to the result, the result differs little from the integral measurement. However, when shooting contrasting scenes, more attention is paid to the exposure of the central part 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 object will either be overexposed or underexposed. In this case, it is better to use partial or spot metering.	It is not known what got into the small measurement area - white snow or dark branches. The result is an almost unpredictable exposure level when shooting "motley" scenes.	There are no obvious restrictions, you need to look at the situation. It is important to remember that sometimes it is impossible to work out 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 measuring the exposure, the automatic device sets the exposure couple - shutter speed and aperture. Numbers appear in the camera viewfinder, for example:

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

Exposure can be adjusted...

It happens that automatic metering is wrong and the photo has a slight overexposure or underexposure. In this case, you can correct the exposure metering 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 on the captured frame? Indeed, on a small LCD screen, often with less than perfect color reproduction, there is little to 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 photograph.

Here is an example of a still image 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 underlight, let's try to correct the exposure by +1/3EV (this is equivalent to the fact that we increase the shutter speed "by 1 click of the wheel", that is, by 1/3 of a step).

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 different ways). The screen will display a slider that can be moved left or right:

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

Here is a variation of the previous shot taken with positive exposure compensation.

We see that the picture brightened a little, the shadows on it improved. 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 their shades and go white. 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 either on the left or on the right. If the histogram is clipped on the left, there are underexposed areas in the photo and there is loss of information in the shadows. If the histogram is cropped on the right, then the photo is losing hues in the light areas.

Sometimes a situation arises when the histogram rests both to the right and to the left - in this case, the image loses details in the shadows and in the highlights at the same time.

Questions and tasks for self-control

1. What types of metering do you have on your camera?
2. Experiment with exposure metering modes. Which scenes are better obtained in the integral metering mode, which - in the spot or partial mode?
3. Find out how your camera's exposure compensation function is enabled.
4. Take pictures of the same scene with positive and negative exposure compensation, follow the changes in the histogram.

There are fundamentals in photography, without knowing which, it is impossible to learn how to take high-quality and beautiful pictures. One of those things is understanding the exposure of a frame. In our article we will talk about shutter speed, aperture and sensitivity. It is these things that form the exposure and an understanding of their work is necessary to get good shots. We will explain what shutter speed, aperture and sensitivity are and how to work with them effectively.

Introduction.

Before writing what shutter speed and aperture are, a small digression. Each frame requires a certain amount of light (exposure). The camera has three options to dose the light output: aperture, shutter speed and sensitivity. Sensitivity is used only when the situation does not allow changing the shutter speed and aperture. In addition to controlling the amount of light entering the sensor, shutter speed and aperture are effective artistic tools. First you need to understand them, and with time and experience, ease of use will come. An experienced photographer uses these tools on a subconscious level.

Diaphragm.

(diaphragma - partition, Greek), in English "aperture" (aperture, English)

Diaphragm- a structural element of the lens, which is responsible for the diameter of the hole that transmits light to a light-sensitive surface (film or matrix).

For a simple understanding of the aperture, I will give an analogy with a window. The wider the window shutters are open, the more light comes through the window.

Aperture is designated as f / 2.8 or f: 2.8, defined as the ratio of the diameter of the lens inlet to the focal length. Very often, the concepts of an open, large aperture (f / 2.8) and a large f / 16 aperture are confused. The smaller the number in the designation of the aperture, the more it is open.

By changing F by one value, the amount of light entering the camera changes by a factor of 2. This is called the exposure stage. Any changes (according to the scales of the camera) exposure occur in 1 step increments. For accuracy, the step is divided into thirds, if necessary.

Aperture is a very powerful visual tool. The maximum open aperture gives a very small depth of field (depth of field of the imaged space). Small depth of field visually highlights the object against a blurred background.

To obtain a large depth of field, the most closed aperture is used. To get a greater depth of field in your frame, use f-number 8 or larger. However, when playing with the aperture value, remember that there are the following dangers when approaching extreme aperture values. When open - the worst sharpness readings, and when closed, all the dust on the matrix will be visible on the frame (for digital cameras).

A large depth of field is more suitable for landscape photography, when it will be interesting for the viewer to see all the details of the photo.

Excerpt.

Excerpt- the time interval for which the shutter opens to transmit light to the photosensitive element.

Again, the open window analogy will help. The longer the shutters are open, the more light will pass through.

Shutter speed is always measured in seconds and milliseconds. Indicated as: 1/200, only the denominator is displayed in the camera: 200. If the shutter speed is a second or longer, it is indicated as 2″ i.e. 2 seconds.

The minimum shutter speed when shooting handheld (to get a sharp shot) is not constant and depends on the focal length. The dependence is inverse, i.e. for 300 mm it is better to use shutter speeds shorter than 1/300.

Long exposure emphasizes the movement of objects. For example, shooting with panning - at slow shutter speeds, 1/60 and longer, the camera follows the object, so the background is blurred, and the object remains sharp.

The flowing water at a slow shutter speed turns into frozen figures.

Very fast shutter speeds, I use to stop a moment, such as a spray of a fallen drop or a car flying by.

ISO sensitivity.

Sensitivity- this is a purely technical concept, denoting the sensitivity of the matrix (or film) to light. Imagine sunbathing people on the beach. Those with more sensitive skin will tan faster; he needs less light for that. The other, on the contrary, needs more light to tan, because he has low sensitivity.

Sensitivity is directly related to the amount of noise. The higher the ISO, the more noise, and the grain size of the film. Why? Purely technically, in general, this is the topic of an extended article.

At ISO 100, the signal is taken from the matrix without amplification, at 200 it is amplified by 2 times, and so on. With any gain, interference and distortion appear, and the greater the gain, the more side effects. They are called noise.

The intensity of noise is different on different cameras. At minimum ISO, noise is not visible and is also less apparent when processing a photo. Starting with ISO 600, almost all cameras are quite noisy, and to get a high-quality frame, you need to use noise reduction programs.

Outcome

Together, the shutter speed and aperture values ​​form an exposure pair (the optimal combination of shutter speed and aperture for the given lighting conditions). Expopara determines the exposure of the frame. Previously, exposure meters were used to determine the exposure, which determined the shutter speed based on the amount of light and aperture. Previously, the exposure meter was used as a separate device, today it is built into almost every camera.

Every DSLR has shutter and aperture priority modes. In aperture priority mode, the aperture is selected, and the camera, analyzing the level of light, selects the shutter speed. The opposite is true in shutter priority mode. Almost always I use aperture priority, it gives the opportunity to work with depth of field. If there is a need to shoot movement, I use the shutter priority mode.

In our next articles, we will continue to talk about the basics of photography. After all, it is in these things that the understanding of the art of photography lies. Knowing them, you will be able to create the shots that you want.

"Photosklad.ru"

The success of a shot can be judged by completely different criteria: a well-captured moment, an accurately conveyed emotion in a portrait, the atmosphere of an interior shot. The list can go on for quite some time.

One factor, such as accurate color reproduction, can be damn important in product photography, but not so important for street photography. What really matters at all times and is the basis of any shot is the light. Or rather, its amount that got into your camera. This is called exposure. Is the frame too dark? This means that not enough light entered the camera, and it came out underexposed. Everything is white, although it shouldn't be? This is a clear sign of an overexposed frame: too much light has hit the camera matrix or film.

Exposure is controlled by changing three parameters: shutter speed, aperture and sensitivity (ISO). Let's look at each of them.

Diaphragm

Aperture is a hole with a variable diameter inside the lens through which light enters directly onto the photosensitive sensor of the matrix or film. The principle of operation of the diaphragm is similar to the principle of the human pupil: the wider it is open, the more light enters the retina. The opposite is also true: to limit the amount of light, say, on a bright sunny day, the pupil narrows noticeably.

Aperture settings are called stops. Here is a typical example of a lens aperture step.

f/1.4 - f/2 - f/2.8 - f/4 - f/5.6 - f/8 - f/11 - f/16 - f/22

The smallest number corresponds to the maximum aperture and the maximum amount of light transmitted. With each successive stop, the amount of transmitted light decreases exactly by a factor of two. Accordingly, the amount of light received by the camera sensor at f/2.8 will be four times less than at f/1.4. In this way, the exposure is controlled by the aperture.

In addition to controlling the incoming light, the aperture is responsible for another important thing in photography - depth of field.

Aperture f/2.8. The background and foreground are noticeably blurred.

Aperture f/8.0. The depth of field displayed is much greater than in the previous image.

Depth of field determines how much the foreground and background are blurred relative to the object you are focusing on. If you take a photo with an open aperture, then you will get a very strong blur of out-of-focus objects. This is called shallow depth of field. If you shoot with a closed aperture, then the depth of the sharply displayed space will increase noticeably.

Depth of field control is important in different genres of photography. When shooting landscapes or interiors, most often you need to get the entire image in the focus area.

On the other hand, the easiest way to separate the subject from the background is to blur it. This technique is often used in portrait photography.

Excerpt

Shutter speed (or exposure time) determines how long the light will hit the camera's sensor or film.

The camera shutter opens only for the duration of the exposure of the photo, allowing the light to reach the matrix for a strictly defined time. Accordingly, the longer the exposure takes, the brighter the photograph is.

Shutter speed control works in a stop system similar to aperture. Each subsequent value reduces the amount of light received exactly by half.

1/2 – 1/4 – 1/8 – 1/15 – 1/30 – 1/60 – 1/125 – 1/250

For 1/4 second, the camera's sensor will receive only half the light that it would receive with an exposure of 1/2 second (with the same shutter speed and aperture settings).

A fast shutter speed allows us to "freeze" the frame, while a slow shutter speed allows us to blur moving objects.

This photo was taken with a shutter speed of 1/1250 second. Such a short exposure time allows you to stop the fast flow of water and see its individual splashes.

And this photo was taken at a shutter speed of a third of a second. The water here looks completely different.

If you want to get a clear photo of something very fast, then you need to take a picture at a fast shutter speed.

ISO

ISO determines how sensitive your camera is to light. The lower the ISO value, the less sensitive the sensor, while a higher value allows you to shoot in very dark conditions. That is, unlike shutter speed and aperture, you do not control the amount of transmitted light, but change the sensitivity of the sensor itself.

At a time when photography was only analog and we could shoot exclusively on film, the sensitivity was chosen only once: at the moment of choosing this same film. Now we can change it at any time by simply changing the settings in the camera.

Stops for ISO: 100 - low sensitivity, 12800 - high. Each new value doubles the exposure of the frame.

100 – 200 – 400 – 800 – 1600 – 3200 – 6400 – 12800

When the sensitivity is increased, noise appears in the photo. Its amount is individual for different cameras. Some cameras produce decent quality images at ISO 6400, while others fall short at these values. In any case, if you want to get the cleanest possible image, try to shoot at a low sensitivity. Another thing is that this is not always possible.

For example, this photo was taken in a theater with low light at ISO 3200 and a shutter speed of 1/100 of a second. If I took a picture at a lower sensitivity, then I would either have to open the aperture more, risking missing focus, or slow down the shutter speed and deprive myself of the opportunity to get a non-blurry image.

How it works with each other

How do sensitivity, aperture and shutter speed work together? Just. Let's look at an example.

Let's say you want to decrease the depth of field in this image and open the aperture to f/2.8.

The result is an image with a more blurred background, but now it is overexposed, because the open aperture allows more light to pass through. In this case, the difference of 2 stops can be compensated by either reducing the shutter speed or reducing the aperture. No one will forbid you to change two parameters at once instead of one. That is, you can either reduce shutter speed or ISO by two stops, or each setting by one.