Publication date: 27.11.2014

In this lesson, we will try to explain in an accessible way how the camera works and what types of cameras exist today. Let's try to approach this issue from a practical point of view, explaining the most important questions for photographers. plain language. This article will help you choose a camera for your tasks, and in the future to enjoy shooting.

How does a camera work?

Everyone knows what a camera is for. But how does it work? Knowing how the camera works will help you always get high-quality pictures. It's the same as with a car: in order to drive a car well, you need to have at least a little idea of ​​how it works.

A simple diagram will help you understand the process of photography.

• Light is the most important thing in photography. Everything starts with him. The word “photography” itself can be translated as “drawing with light”, “light painting”. Light begins its journey from a source, such as the sun.
• Light falls on everything around us. This is very important to remember: the camera does not capture the objects themselves, but the light reflected from them. It is light and the ability to work with it that is the key to good shots.
• The light reflected from the object passes through the lens of the camera.
• It is projected onto a photosensitive sensor - a matrix. Before, when there were no digital cameras, film was used instead of a matrix.

• The matrix consists of millions of photosensitive elements. They capture light and transmit information about it already in in electronic format to the camera processor. The processor processes the received data and saves it as a file.

• The file is written to the memory card.

All modern digital cameras work on this principle, differing only in some details.

Camera sensor

The matrix is ​​the heart of the modern camera. The quality of the photos will largely depend on its quality. The matrix has two main characteristics, information about which is available to the consumer: resolution and physical size.

Let's deal with resolution first. The resolution of a matrix is ​​​​the number of its light-sensitive elements, pixels. The more of them, the more dots will make up the final photo. Today, the average resolution of matrices is from 16 to 36 million pixels.

However, it may be that there are a lot of megapixels on the matrix, but the image quality is still not high: it is not sharp, not contrasty, drowning in digital noise - interference. Image quality depends not only on the resolution in megapixels, but also on the physical size of the matrix itself.

Both pictures were taken at the same resolution. As you can see, the frame shot on mobile phone, loses a lot in quality: it is not so contrasting, small details are not preserved in the picture, for example, veins on a leaflet. But it is precisely for small details that the high resolution of the matrix should be responsible.

AT Various types cameras are equipped with matrices of various sizes. The largest in this diagram is a full-frame matrix. Its size corresponds to a frame with a familiar “135” or simply “35 mm” film - 36x24 mm. Matrices of this size allow you to get images of very high quality. But the larger the physical size of the matrix, the more expensive it is. Therefore, large matrices are found only in fairly expensive devices. For amateur DSLRs, the APS-C format is typical. The cheaper the device, the smaller the matrix installed in it.

Large matrices give a gain not only in detail, but also in image quality when shooting at high sensitivity values, in poor lighting conditions. The point is that the sensor large area it is possible to realize a larger size of the photosensitive elements themselves - pixels. For comparison: one photosensitive element of the matrix of a modern full-frame camera has an average size of 4.9-8.3 microns. The size of one pixel of a compact camera or smartphone is about 1-3 microns.

Features of large and small matrices

The advantages of large sensors - full-frame and APS-C - are obvious: they give better image quality. At the same time, working with them has several nuances. The laws of optics are such that when working with a large matrix, we get a small depth of field in the photo. On the one hand, we can beautifully blur the background in our pictures. But at the same time, difficulties will arise if we want to make everything sharp in the picture - both the foreground and the background. When shooting with a SLR camera, it is not always possible to achieve a large depth of field.

At the same time, small sensors allow you to shoot with an almost infinite depth of field. The smaller the matrix, the easier it is to get a frame with a large depth of field. That is why, when shooting on a smartphone or a compact device, it is difficult to blur the background in the picture: the depth of field is too large, everything in the picture becomes clear. Let's compare two frames taken with the same shooting parameters, but on cameras with sensors of different sizes.

A shot taken with a compact device with a small 2/3" sensor. Almost all the figures fell into the depth of field.

If you like blurry backgrounds in photos, if you are into portrait photography, then most likely you will need a camera with a large sensor - APS-C format or even 24x36 mm.

In addition, the size of the camera itself and the lenses for it directly depend on the size of the matrix. Moreover, if the size of the body of the device can still be made more or less compact even when using a full-frame matrix, then it will not work to reduce the size of the lens: the laws of optics will not allow it. Therefore, when buying a full-frame camera with interchangeable lenses, be prepared for the fact that a good lens will have a solid size and weight. If you want to use a full-frame camera and at the same time have a compact lens, you will have to be content with not the most versatile and not the most fast lenses. But in cameras that use smaller sensors, it is quite possible to use lenses that are lighter, more compact. Compare yourself.

Camera types. Their pros and cons.

With the heart of a digital camera, the matrix, we figured it out. Now let's figure out what types modern cameras are divided into.

Mobile camera. Phone camera

Today, a built-in camera can be found in many devices. In smartphones, a camera (and sometimes not even one, but two - the main one and the front one) has become an indispensable element. Probably every reader has the experience of taking pictures on the phone. In pursuit of compactness, such cameras are equipped with tiny matrices and simple lenses. We all know that phone pictures do not pretend to be high quality, but such shooting does not require special skills, and the phone is always at hand. However, if you are planning to do photography more or less seriously, you should think about a more advanced creative tool that provides higher quality images and manual setting of shooting parameters.

Compact cameras

Perhaps this type of camera is also familiar to everyone. There is a compact camera in almost every home. Their main advantage is their small size, low price, ease of use and sometimes a great zoom.

Small and medium matrices with a diagonal of 1/2.3”, 1/1.7”, 1” are usually placed in cameras of this type. This provides these devices with compactness and a very affordable price. Of course, there are rare models of compacts with large matrices, even full-frame ones. But these are quite specific and expensive devices.

Compact cameras have a fixed lens. As a rule, such cameras are equipped with a universal lens that allows you to shoot both with wide angle review and take pictures close-up objects removed from us. Again, thanks to the use of small-sized matrices, it turns out to make the lens small in size.

Most compact cameras are geared towards shooting in automatic modes to make taking pictures as easy as possible. In English, they are called “Point-and-shoot”, which can be translated into Russian as “point-and-shoot”. Indeed, to shoot with such a device, it is enough to press only one button, the rest will be done by automation. But for shooting with manual settings these devices are not always calculated. Sometimes not all settings can be configured manually, and if it is possible, then you have to look for them somewhere in the device's menu, which slows down the process.

The so-called “hyperzooms” (“superzooms”, “ultrazooms”) stand apart in the class of compacts. Hyperzoom is a compact camera equipped with a lens with a very high zoom ratio. It can shoot both with a wide viewing angle and take close-ups of very distant objects. Lenses with such a large zoom are relatively large, which is why the camera loses its compactness and is comparable in size, and often in price, with more advanced camera classes.

Who are compact cameras and hyperzooms suitable for?

First of all, for those for whom photography is neither a hobby nor a profession. For those who just shoot as a keepsake and don't want to load their heads with some complicated settings. These cameras are perfect for traveling light. They always have automatic modes, which will allow even a beginner to cope with them. Professional photographers sometimes choose a compact as a second, auxiliary camera.

SLR cameras

The next type of cameras are SLRs or DSLRs. As a class of equipment they have a rich history. The first DSLRs appeared in the first half of the last century. Then they used film. For more than half a century, their design has been brought to almost perfection, and only in the 21st century did the digital matrix replace the film.

SLR devices are so named because their design includes a system of a mirror and a special reflective prism (pentaprism), which allows you to see exactly the picture that the lens “sees”. And, without any electronics.

The mirror has a movable design: when it is lowered, light enters the viewfinder. When a picture is taken, the mirror is raised and the light hits the sensor. Used with SLR cameras interchangeable lenses . You can choose any lens for your camera from a wide range of model range, focusing on the type of filming that you want to do. Thus, in any situation, you can get the perfect tool for perfect image quality.

SLR cameras are called system cameras for a reason. When choosing a DSLR of one or another manufacturer, we choose system from the camera, lenses and accessories (such as flashes). This is actively used by all professional photographers and advanced amateurs.

AT reflex cameras large matrices are always used. APS-C format or even full frame. And as mentioned above, a large matrix is ​​one of the components of a high-quality image.

The speed of work is the next advantage of SLR cameras. A photographer who has switched from a compact to a DSLR may be simply shocked by the speed of its work. Fast autofocus and instant response to all manipulations of the photographer - the property of any DSLR.

The reflex camera is very operative in management. Manufacturers pay great attention to their design, because this is a professional tool. The device is comfortable to hold in your hands, and almost any setting can be adjusted with one or two buttons without getting into the menu.

Another advantage worth noting is long work from the battery. It is relatively rare to charge the battery of such a camera. Since the matrix in a DSLR (together with the display of the device - the main consumer of energy) is not always under load, but only directly during the shooting of a frame, the battery allows you to take about 500-1000 shots on a single charge, depending on the camera model. This is an almost unattainable figure for other types of cameras. Long battery life of the camera is a very important thing when traveling, trips, long walks.

Of the minuses of SLR cameras, perhaps it is worth noting their large weight and size. However, many photographers, on the contrary, like to walk around with a large camera and look like a professional. Modern DSLRs are both very expensive, designed for professional use, and very affordable. Today almost everyone can afford a SLR camera.

Who is a DSLR for?

Anyone who is more or less seriously involved in photography and is not afraid of the relatively large size of the camera. For those who want to learn how to photograph professionally, to make photography their profession, a SLR camera is the best choice.

Compact cameras with interchangeable lenses or mirrorless cameras

This is a relatively recent type of camera and the most actively developing. Manufacturers reasonably decided that if you equip an ordinary compact camera with interchangeable lenses and a high-quality matrix, you will get very interesting thing. Mirrorless cameras combine most of the advantages of DSLRs and compacts. As already mentioned, "mirrorless" have interchangeable lenses and compact dimensions. This allows you to take pictures of very high quality. After all, they are equipped with matrices of relatively large sizes.

Mirrorless cameras are generally pretty fast in operation. However, due to their miniature size, their ergonomics suffered a little. The camera no longer lies in the hand as comfortably and thoroughly as a DSLR. And many photographers do not like the lack of an optical viewfinder. Of the other disadvantages of mirrorless cameras, it is worth noting the rather short battery life.

Manufacturers in this class of cameras pay special attention to style. In contrast to the strict black DSLRs aimed at advanced photographers, there are a lot of beautiful, stylish, “image” models among mirrorless ones.

Who is a mirrorless camera for?

For those who want to receive high quality photos, but at the same time does not want to carry a bulky SLR camera. This camera is great for taking on trips. However, if you're planning a trip without the ability to charge your camera, it's a good idea to bring a set of spare batteries with you.

Medium format cameras and digital backs

There are cameras in which the matrix is ​​even larger in size than that of full-frame DSLRs. For example, its size may be 44 x 33 mm, 53.9 x 40.4. The resolution of such large matrices is also rather big: several tens of megapixels.

Cameras of this type are called "medium format". This name has remained since the days of film photography. In the film era, wide film was used in such cameras, much wider than usual. Such cameras were then and are still used by some professional photographers to take very high quality photographs. Prints with a diagonal of about one meter are not the limit for these cameras. Some of these cameras are equipped with interchangeable modules in which the matrix and electronic filling are installed directly. Such modules are called digital backs. Medium format cameras are mainly used when shooting in a photo studio due to their large size and not very high efficiency in work. Another disadvantage of medium format cameras is the price comparable to the price of a new foreign car.

Konstantin Voronov

Professional photographer with ten years of experience. She has been teaching for six years. Journalist by education, author of courses and educational articles on photography. Sphere of interests - landscape, object, portrait photography.

97645 Photography from scratch 0

In this lesson you will learn: The principle of operation of the camera. What are the basic elements of a camera?

The principle of operation of a digital camera

Photography is primarily about light. Consider the drawing.

Light from the sun or an artificial source (1) is first reflected from the scene in front of the camera lens, and then passes through the lens (2) and, if present, the shutter (7) (you will learn about the shutter a little later in this lesson) to the rear wall of the camera body - on the matrix (sensor) (8). In a reflex camera (DSLR), before pressing the shutter button, the light reflected by the mirror (3), passing through the prism (4), enters the viewfinder (5). When shooting, the mirror is raised, and the light falls on the matrix, as in a compact camera. In some Sony SLR cameras, the mirror is fixed, translucent (SLT cameras).

This process is similar to the passage of light through the lens of the human eye to the cones and rods located at the back of the eye, as well as to the optic nerves. When the light reaches the rear wall of the housing, it hits a sensitive element (image sensor), which converts the light into electrical voltage. Then, the information thus obtained is processed by a processor to remove noise, calculate color values, generate an image data file, and write the image data file to a storage medium (digital image storage card). The camera then prepares to expose the next image.

This whole process, during which a huge amount of information is processed and written to the media, occurs quite quickly.

Below are pictures that give an idea of ​​the main elements that make up a compact (mirrorless) and SLR camera.

Compact camera

Camera

Let's take a closer look at these basic elements that make up a digital camera and that allow the light reflected from the subject to become a photograph.

Lens

The camera lens is a very complex structure. Typically, it consists of a number of glass lenses that refract and focus the light entering the lens. This magnifies the image of the scene being shot and focuses on a specific point. You will learn more about lenses in later lessons.

Viewfinder and LCD screen

The viewfinder allows you to see the image at the time of shooting and some of the shooting parameters, and is a small window through which the scene being shot is observed. With it, the composition is refined immediately before shooting.

The LCD screen provides a preview of pictures before taking them, as well as the subsequent review and analysis of pictures just taken for the correct exposure and composition, or for showing them to others. In addition, any previously taken pictures can be viewed on the LCD screen.

In digital cameras, the LCD screen can also act as a viewfinder. Instead of bringing the camera up to your eye to compose the scene, you can prepare it for shooting in any position by viewing the image on the LCD screen before it is captured. One disadvantage of LCD screens is the high power consumption of the camera battery. In addition, viewing images on the LCD screen on a sunny day outdoors is almost impossible.

Despite all the advantages of the LCD screen listed above, the viewfinder is sometimes useful in a digital camera. In particular, when the battery power is running out and therefore it is inappropriate to expend precious energy on powering the LCD screen. Whatever it was, but the viewfinder still serves as a convenient alternative to the LCD screen when composing a photograph.
With digital SLR cameras, the viewfinder and LCD screen show the same image, since mirrors are used to project the image from the lens into the viewfinder. In compact digital cameras, the viewfinder serves as a simple window through which the scene being shot is seen, rather than the image being projected through the preview lens. But since the viewfinder is not in the same place as the lens, the perspective observed through it is somewhat different.

Gate

The shutter is a complex mechanism that precisely controls how long light passes through the lens to the film or digital sensor on the back of the camera body.

In a digital camera, a shutter in the traditional sense may not be needed, depending on the type of image sensor used. Since the image sensor of a digital camera is an electronic device and not a photosensitive chemical, it can be turned on or off electronically. Therefore, there is no need for a mechanical shutter to control the amount of light entering the camera. However, some types of cameras still require a shutter, although many digital cameras do not have a mechanical shutter.

Regardless of the presence or absence of a mechanical shutter, a digital camera still needs a mechanism to control the exposure of the image, as well as a shutter button. When you press the shutter button, a series of actions are activated that ultimately lead to the final image. First of all, you need to charge the image sensor to prepare it to receive light from the lens.

Buttons for camera settings

There are many buttons, levers, dials on the camera body, the purpose of which is best described in the instructions for your camera. Most of them serve to prepare the camera for shooting, set it up and shoot directly.

These include: setting the auto focus mode, choosing an appropriate white balance to ensure that the colors of the scene are correctly reproduced depending on the type of lighting used, choosing an exposure mode, etc. You will learn more about these and other parameters in later lessons.

Image sensor

The image sensor is made up of millions of individual light sensitive pixels. In these pixels, in fact, the conversion of light into electrical voltage is performed.

Although digital cameras allow you to take multi-color pictures, their image sensors do not pick up color. They are only able to respond to the relative brightness of the scene. To limit the spectrum of light to which each pixel of the image sensor responds, special color filters are used. Thus, in each pixel, only one of the three primary colors (red, green or blue) can be registered, which are necessary to determine the final color of the pixel. And to determine the values ​​of the other two primary colors of each pixel, color interpolation is used.

You will learn more about image sensors in our next tutorial.

Built-in flash

A built-in flash is found in most digital cameras. Of course, this is very convenient, since there is often not enough light in the surrounding conditions. On the other hand, flashes built into many cameras are not always practical. This is partly due to the lack of built-in flash control. Indeed, in most models of digital cameras, you cannot adjust the power of the built-in flash, and therefore, you have to rely entirely on the camera when judging the level of lighting.

The inability to adjust the power and position of the built-in flash turns into a serious obstacle when shooting subjects close to the camera. In this case, the flash illuminates the scene too much, resulting in an image with excessive contrast. Due to the fact that the built-in flash is very close to the lens, red-eye often appears in pictures.

To mount on camera external flash and another necessary equipment(viewfinder if there is none in the camera, microphone, etc.) serves as a hot shoe connector.

carriers digital information

In a digital camera, each captured image is recorded on a digital media card. To some extent, this card replaces film (and therefore is sometimes called digital film), but it has its own characteristics.

Carriers of digital information are the most different forms and sizes: from the size of a book to the size of a chewing gum plate and even less. And some even have the ability to use multiple media types for added convenience.

Digital camera power

Rechargeable batteries are the most commonly used power source in digital cameras. According to the size of the case, the elements are divided into several types. In digital filming equipment, AAA and AA format elements are used (in other words, “the thinnest” and “thin batteries”) or there is a proprietary design that is not compatible with cameras from other manufacturers. Batteries are placed in a special compartment of the camera, where sometimes some people look for the "masterpiece" button :))).

DSLRs and some interchangeable lens mirrorless cameras use battery packs that house multiple batteries to significantly extend the camera's battery life.

Lesson results:

So, we have considered the basic elements of the design of a digital camera. A very important subject that is often forgotten to learn, and sometimes simply lost, is the camera manual.

Analyzing the search queries that bring visitors to our site, I state that there are a lot of questions "how to enable" any camera function. In order to get the most out of your camera, you need to carefully read the manual that came with it, which users are often too lazy to do, relying on their ability to figure out new equipment along the way. As practice shows - you will not understand or you will begin to understand at the most inopportune moment.

This is your first practical assignment. - carefully study the manual (or instructions) for the operation of your camera.

You can ask questions on the topic of the first lesson, on the material presented and on the practical task on the site.

And in the end - a short video "How does the mirror digital camera".

In the next lesson #2: Camera types. The main characteristics of modern cameras. Learn more about sensors. Let's talk about megapixels. We will tell you how to choose a camera.

Having felt the camera in their hands for the first time and having tried to take a few shots, any beginner has a completely logical question: “How does it work?”, “What does a modern camera consist of?”. In this article, we will try to describe the camera device in as much detail as possible and make it easy and interesting. Go!

So what is a digital camera made of?

• Carcass or as many professionals say body (eng. "body") - a body consisting of plastic or magnesium alloy does not transmit light.
• Bayonet - lenses are attached to it.
• Lens - consists of a lens system (1). With it, the image of the shooting objects is projected onto the matrix.
• Aperture is a partition (2), which is located inside the lens, and also looks like petals. They form a hole whose diameter can be adjusted.
• The mirror (3) is the most important thing. It directs the image created by the lens to the focusing screen (6) and then through the pentaprism (7) to the viewfinder (8).
• The focus screen is a matte plate with which the photographer sees the image through the viewfinder.
• A pentaprism is an element that flips an image.
• The viewfinder is a kind of "peephole" through which the photographer sees the future picture.
• The sensor is an electronic matrix (5), which, sensing the light, replaces the film in the device of a reflex camera.
• Processor - reads and processes images that appear on the matrix.
• Memory card - carefully stores our photos.
• The shutter is a mechanical shutter (4) that is located between the sensor and the camera mirror. At the time of shooting, they temporarily open so that the light hits the matrix.
• The battery is the power supply for the camera and all its elements.
• Tripod socket (11) – tripod socket.
• "Hot shoe" (10) - an external flash is connected to it.
• Display (9) - for viewing photos, as well as for setting the necessary shooting parameters.
• Controls - various buttons, wheels and dials for controlling and adjusting the camera.

We have not listed all the parts, but it is better to limit ourselves to this set, so that when analyzing the principles of action in the future, you will not get confused.

Digital camera device: principle of operation

All novice photographers (especially boys) are probably interested in what happens inside the camera at the moment when you decide to take a picture and press the button. And the following happens:

1. When shooting in auto mode, the lens automatically focuses on the subject.
2. Then the mechanical or optical image stabilizer does its job, namely, it stabilizes the image.
3. Again, when shooting in auto mode, the camera itself selects the parameters: shutter speed, aperture, ISO, and white balance.
4. Then the mirror (3) rises.
5. And the shutter (4) opens.
6. The light that passes through the lens forms an image on the sensor, which is then read by the processor and stored in the card.
7. The shutter is closed.
8. The mirror is down.

What is a camera lens made of?

Now there are so many different types and brands of lenses that it is simply not realistic to understand the composition of each within the framework of a small informative article. The lens device of a SLR camera can have a different number of optical elements or lenses. They can connect with each other or, on the contrary, be separated by a small space. In simple lenses, a system is usually used, which can consist of one to three lenses. As for expensive high-quality lenses, the number of lenses in the system can be about a dozen or more.

Camera flash device

The most important element of any electronic flash is a pulsed xenon light bulb. This is a sealed glass tube (arc-shaped, spiral, straight or annular), which is filled with xenon. At the ends of the tube there are soldered electrodes, on the outside there is an incendiary electrode, which is a strip of mastic or a piece of wire that conducts current.

Flashes are:

• The built-in ones are not very powerful, they give a flat image, create sharp contrasting shadows. Not able to highlight the structure of the subject. Great for use in bright natural light, highlighting harsh shadows. But it is worth noting that professional photographers do not advise using the built-in flash when shooting.
• Fixed - more powerful than the built-in ones, they can also be configured both manually and automatically.
• Not attached to the camera - usually these are mounted on a tripod. With the help of them you can change the lighting conditions, play with light.
• Macro flashes are used for macro photography. They look like a small ring that is mounted on the camera lens.

Camera shutter device

As we wrote above, the shutter in the camera is used to block the flow of light that projects the lens onto the matrix or film. By opening the shutter for a given exposure time, the amount of light is dosed - this is how the exposure is adjusted.

Closure types:

1. disk sector shutter;
2. shutters-blinds;
3. central shutter;
4. diaphragm shutter;
5. focal shutter.

Camera matrix device

A modern matrix is ​​a small microcircuit. The surface of this microcircuit consists of many light-sensitive elements, each of which is an independent light receiver. It converts light into a certain signal, which, after processing, is stored on a memory card. The picture that the photographer receives consists of a complex of recorded electronic signals from each photosensitive element. Interesting, right?

Zenith camera device

What the SLR camera consists of, we have already found out, now the turn of the Zenith film camera has come. It consists of:

• lens
• mirrors;
• shutter;
• photographic films;
• frosted glass;
• condenser (lens);
• pentaprism or pentamirror;
• eyepiece.

Of course, we have not listed everything. In order to find out in more detail what a camera (both digital and film) consists of, you need to write it down in ours, where an experienced teacher will tell you about each nut and demonstrate everything with a good example.

Digital camera device

The history of the development of photographic equipment has led to the fact that certain standards have been developed for the interface between the photographer and the photographic equipment he uses. As a result, digital cameras (digital camera, DPC) in most of their external features and controls repeat the models of film photography. The fundamental difference is in the “stuffing” of the device, in the technologies of fixation and subsequent image processing.

Basic elements of a digital camera

Matrix

The main element of any digital photo or video camera is a matrix, from which the largest [ neutrality?] degree depends on the quality of the resulting image.

A matrix (sometimes called a sensor) is a semiconductor wafer containing a large number of photosensitive elements, in the vast majority of cases grouped in rows and columns.

In modern DPCs, two types of matrices are most widely used: CCD (charge-coupled device, in English CCD - Charge-Coupled Device) and CMOS (complementary metal-oxide-semiconductor, in English CMOS - Complementary-symmetry / Metal-Oxide Semiconductor ).

CMOS sensors for consumer cameras are relatively cheap, as they are manufactured using standard semiconductor technologies, but the noise of such sensors is usually much higher than that of CCDs. Therefore, at present, most DPC models (with the exception of a number of professional and semi-professional "SLRs" by Canon, Nikon and Sony and others with special noise suppression circuits) are equipped with CCD matrices. The name CCD - charge-coupled device, reflects the method of reading the electric charge by shifting from one matrix element to another, gradually filling the buffer register. Further, the voltage is amplified and fed to the ADC (analogue-to-digital converter), after which already in digital form enters the camera processor for further processing.

Lens

Gate

Digital consumer cameras are equipped with an electronic equivalent of a shutter that is built into the sensor and performs the same job as a mechanical one. In more expensive cameras, two shutters are mounted, and the mechanical one serves to prevent light from reaching the sensor after the exposure time has elapsed, which avoids the appearance of halo artifacts, partial blooming and smearing.

In some digital cameras, pressing the shutter button halfway activates the automation systems. Autofocus and exposure detection system fix the shooting parameters and wait for a full press. By fully pressing the release button

• in non-mirror digital devices:
  • the mechanical shutter (if present) opens,
  • there is a discharge of the charge in the cells of the matrix,
  • the mechanical shutter opens for the duration of the exposure,
  • the mechanical shutter closes,
  • a frame is read from the matrix,
  • the mechanical shutter opens,
  • the matrix goes into Live View mode;

• in a digital reflex camera (without or with Live View turned off):
  • the mirror rises and the "jumping" diaphragm is activated,
  • the previously disabled matrix is ​​​​turned on,
  • the mechanical shutter opens for the duration of the exposure,
  • the mechanical shutter closes
  • the mirror is lowered and the aperture is opened,
  • the frame is read and processed from the matrix.

Viewfinders

View in the viewfinder screen of a rangefinder camera.

The viewfinder is an element of the camera that shows the boundaries of the future image and, in some cases, the sharpness and shooting parameters. On consumer digital cameras, LCD screens are used as a viewfinder (on SLRs in LiveView mode and on compact cameras) and different kinds electronic and optical viewfinders.

CPU

Processors in digital cameras perform the following functions:

• shutter control;
• lens control in automatic and manual shooting modes;
• selection of white balance, measurement of the illumination of an object, determination of exposure pair, selection of color temperature, etc.;
• flash control;
• bracketing control - the possibility of continuous shooting (usually in series of 3 or 10 frames) with different camera settings;
• management of special effects from the existing set (sepia, black and white, red-eye removal, etc.);
• formation and display of information about the selected shooting modes, settings, the image itself, etc.

Memory card

Flash cards.

A memory card is a storage medium that provides long-term storage of large volume data, including images taken by a digital camera.

Early models of digital cameras used other storage media, including miniature hard drives, floppy disks, recordable optical and magneto-optical disks, etc., up to audio cassettes (in the very first sample of a Kodak electronic camera that used analog methods processing and saving images).

Connectors and interfaces

An external interface for connecting to a general-purpose computer is available in almost all digital cameras Oh. Today () the most common of them is USB. Special types of connectors are also used for connecting to a TV or printer. The first models of cameras with wireless interfaces appeared.

Governing bodies

Choice of operating modes

Camera mode dial - camera mode selector. Usually located on the top panel of the camera on the left or right. Less often, mainly on compact cameras, on the panel facing the photographer. Some digital cameras do not have a mode dial, and the shooting mode is selected using buttons and menus.

Shutter button (Shutter key)

A photo capture control that initiates a capture sequence. It is carried out in the form of a button either on the upper end of the device (compact cameras), or in front and on the side of the handle in SLR cameras. When pressed, the camera shoots and processes the frame. Many models have a 2-step press (when pressed halfway, autofocus and exposure compensation technologies are triggered, when pressed fully, a picture is taken.)

Menu control

Most digital cameras use a menu interface to configure settings.

Many compact cameras have two menus: the main menu and the quick menu. The main menu occupies the entire screen space and is intended for setting both the shooting parameters and the device's system parameters (date, time, etc.). The "quick" menu is displayed over the image in shooting mode and allows you to directly change the shooting parameters, for example, ISO, white balance, exposure compensation, etc.

In digital SLR cameras, when the Live View mode is off, only the shooting parameters are displayed on the screen (if it is on). The same interface is present in some compact cameras, for example, in the Canon PowerShot G11 in the "Quick Shot" mode (in this mode, zooming is only possible using the optical viewfinder).

Other

Digital camera operation

Before pressing the shutter button in SLR cameras, a mirror is located between the lens and the matrix, reflecting from which the light enters the viewfinder. In non-mirror cameras and SLR cameras in Live View mode, the light from the lens falls on the matrix, while the image formed on the matrix is ​​displayed on the LCD screen. In some cameras, this may cause automatic focusing.

When the shutter key is pressed halfway (if such a mode is provided), all automatically selected shooting parameters are selected (focusing, determining exposure pair, photographic material sensitivity (ISO), etc.).

When fully pressed, the information is read from the matrix into the built-in memory of the camera (buffer). Next, the received data is processed by the processor, taking into account the set parameters for exposure compensation, ISO, white balance, etc., after which the data is compressed into JPEG format and saved to a flash card. When shooting in RAW format, the data is saved to a flash card without processing by the processor (correction of dead pixels and compression by a lossless algorithm is possible). Since it takes quite a long time to write an image to a flash card, many cameras allow you to shoot the next frame before the previous one is written to the flash card, if there is free space in the buffer.

see also

• red-eye effect

Notes

Literature

• Nikon's guide to digital photography with the D50 digital camera. - M.: "Nikon Corporation", 2007. - 137 p.

Modern digital cameras are a lot like old film cameras. And this is not surprising, because digital photography, in fact, grew out of the film one, borrowing various nodes and components. A special similarity can be traced between a SLR digital camera and a film camera: after all, a lens is used both there and there, with the help of which the device focuses on the object being shot. A similar process: the photographer simply presses the shutter button and, ultimately, a photographic image is obtained.

However, despite the similarity of the shooting process, the device of a digital camera is much more complex than film. And this design complexity provides digital cameras with significant advantages - instant shooting results, convenience, wide functionality for managing photography and image processing. In order to understand the device of a digital camera, you must first answer the following questions: next questions: How is a photograph created? What nodes did the digital camera borrow from film? And what's new in the camera with the development of digital technology?

How film and digital cameras work

The principle of operation of a conventional film camera is as follows. Light reflected from the object or scene being photographed passes through the lens aperture and is focused in a special way on a flexible, polymer film. The photographic film is coated with a light-sensitive emulsion layer based on silver halide. The smallest granules chemical substances on the film under the action of light change their transparency and color. As a result, the photographic film "remembers" the image due to chemical reactions.

As you know, to form any shade that exists in nature, it is enough to use a combination of three primary colors - red, green and blue. All other colors and shades are obtained by mixing them and changing the saturation. Each microgranule on the surface of the film is responsible, respectively, for its color in the image and changes its properties precisely to the extent that it is hit by light rays.

Since the light differs in color temperature and intensity, as a result of a chemical reaction on the film, an almost complete duplication of the scene being shot is obtained. Depending on the characteristics of the optics, illumination, exposure time / exposure of the scene on the film and aperture opening time, as well as other factors, one or another style of photography is formed.

As for the digital camera, the optics system is also used here. Rays of light pass through an objective lens, being refracted in a special way. Next, they reach the aperture, that is, a hole with a variable size, through which the amount of light is regulated. Further, when photographing, the light rays no longer fall on the emulsion layer of the film, but on the light-sensitive cells of the semiconductor sensor or matrix. The sensitive sensor reacts to light photons, captures a photographic image and transmits it to an analog-to-digital converter (ADC).

The latter analyzes simple, analog electrical impulses and converts them into digital form using special algorithms. This transcoded image is digitally stored on the built-in or external electronic media. The finished image can already be viewed on the LCD screen of a digital camera, or displayed on a computer monitor.

Throughout this multi-stage process of obtaining a photographic image, the camera electronics continuously interrogates the system for an immediate reaction to the actions of the photographer. The photographer himself, through numerous buttons, controls and settings, can influence the quality and style of the resulting digital image. And all this complex process inside a digital camera takes place in a matter of fractions of a second.

Basic elements of a digital camera

Even visually, the body of a digital camera is similar to a film camera, except that the digital camera does not provide for a film reel and a film channel. Film was fixed on the reel in film cameras. And at the end of the frames on the film, the photographer had to rewind the frames in the opposite direction manually. In the film channel, the film was rewound to the frame needed for shooting.

In digital cameras, all this has sunk into oblivion, and by getting rid of the film channel and the place for the film reel, it was possible to make the camera body much thinner. However, some of the bridles of film cameras smoothly passed into digital photography. To see this, let's look at the main elements of a modern digital camera:

- Lens

Both film and digital cameras light rays pass through the lens to obtain an image. A lens is an optical device consisting of a set of lenses and used to project an image on a plane. In SLR digital cameras, they are practically no different from those used in film cameras. Moreover, many modern DSLRs are compatible with lenses designed for film models. For example, older F-mount lenses can be used with all digital SLR cameras Nikon.

- Aperture and shutter

- this is a round hole through which you can adjust the amount of light flux falling on a photosensitive matrix or film. This variable opening, usually located inside the lens, is formed by several crescent-shaped petals that converge or diverge when shooting. Naturally, the diaphragm is available in both film and digital cameras.

The same can be said about the shutter, which is installed between the matrix (film) and the lens. True, film cameras use a mechanical shutter, which is a kind of curtain that limits the effect of light on the film. Modern digital devices are equipped with an electronic shutter equivalent that can turn on / off the sensor to receive the incoming light flux. Electronic provides precise regulation of the time of light reception by the camera matrix.

In some digital cameras, however, there is also a traditional mechanical shutter, which serves to prevent light rays from reaching the matrix after the exposure time has elapsed. This prevents blurring of the picture or the appearance of the halo effect. It is worth noting that since it can take a digital camera some time to process and save the image, there is a time lag between the moment the photographer presses the shutter button and the moment the camera captures the image. This time delay is called shutter lag.

- Viewfinder

Both film and digital cameras have a sighting device, that is, a device for preliminary evaluation of the frame. An optical viewfinder, consisting of mirrors and a pentaprism, shows the photographer the image exactly as it exists in nature. However, many modern digital cameras are equipped with an electronic viewfinder. It takes an image from a photosensitive matrix and shows the photographer the way the camera sees it, taking into account the preset settings and the effects used.

In inexpensive compact digital cameras, the viewfinder as such may simply be absent. Its functions are performed by the built-in LCD screen with LiveView function. LCD screens are now built into digital reflex cameras, because thanks to such a screen, the photographer can immediately view the results of the shooting. Thus, if the picture is not successful, you can immediately delete it and shoot a new frame with different settings or from a different angle.

- Matrix and analog-to-digital converter (ADC)

After we examined the principle of operation of a film and digital camera, it became clear what the main difference between them actually is. In a digital camera, instead of film, a light-sensitive matrix or sensor appeared. The matrix is ​​a semiconductor wafer on which a huge number of photocells are placed.

Do not exceed the size of a photographic film frame. Each of the sensitive elements of the matrix, when a light flux hits it, creates a minimum image element - a pixel, that is, a one-color square or rectangle. Sensor elements react to light and create an electrical charge. Thus, the matrix of a digital camera captures light fluxes.

The matrix of a digital camera is characterized by such parameters as physical dimensions, resolution and sensitivity, that is, the ability of the matrix to accurately capture the flow of light falling on it. All these parameters have an impact on the quality of the photo image.

The information received from the sensor in the form of electrical impulses is then sent for processing to an analog-to-digital converter (ADC). The function of the latter is to convert these analog pulses into a digital data stream, that is, to convert the image into digital form.

- Microprocessor

The microprocessor was present in some of the latest film cameras, but in the digital camera it has become one of the key elements. The microprocessor is responsible in "digital" for the operation of the shutter, viewfinder, matrix, autofocus, image stabilization system, optics, as well as recording the captured photo and video material on the media, selecting settings and program shooting modes. This is a kind of brain center of the camera that controls all electronics and individual nodes.

The performance of the microprocessor largely determines how fast a digital camera can shoot continuously. In this regard, in some advanced models of digital cameras, two microprocessors are used at once, which can perform individual operations in parallel. This ensures maximum burst shooting speed.

— Information carrier

If an analog (film) camera immediately captures an image on film, then in a digital one, the electronics records the image in digital format on an external or internal storage medium. For this purpose, in most cases are used. But some cameras also have a small built-in memory, which is enough to accommodate several captured frames.

Also, digital cameras must be equipped with the appropriate connectors so that they can be connected to a personal or tablet computer, TV and other devices. Thanks to this, the photographer gets the opportunity, just a few minutes after shooting, to place the finished image on the Internet, transfer it via e-mail or print.

- Battery

Many film cameras use a rechargeable battery to power electronics that control the focus and auto exposure of a scene, among other things. But this work does not require significant power consumption, so a film camera can work for several weeks on a single battery charge.

Another thing is digital photography. Here, the battery life of a camera is measured in hours. Therefore, in order to maintain the operation of the camera in the absence of a source of electricity, the photographer sometimes has to stock up on additional batteries.

Despite the fact that digital photography has borrowed many components from film photography, it has a number of significant advantages. First of all, it is the ability to quickly control the results of shooting and make the necessary adjustments. A digital camera, due to the nature of its device, gives any photographer more flexibility in the process of shooting due to the wide range of image quality control. Digital technologies provide instant access to any frame and high-speed photography. The combination of flexibility, rich functionality and speed of shooting ensures that the owner of a digital camera takes excellent quality photos in almost any conditions.

The possibilities of digital photographic equipment today are far from being exhausted. As digital cameras develop, they will become more and more complex, new technologies will be implemented in them, increasing the functionality of the devices and providing even higher image quality.