The principle of the digital camera. Camera device, structure and principle of operation

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 in most of their external features and controls repeat the most advanced models of film technology. The fundamental difference turns out to be in the "stuffing" of the device, in the technologies of fixation and subsequent processing of the image.

Basic elements of a digital camera

• Matrix
• Lens
• Gate
• Video Finders
• CPU
• Display
• Flash

DSLR device

A DSLR is a camera in which the viewfinder lens and the lens for capturing the image are the same, and the camera also uses a digital matrix to record the image. In a non-SLR camera, an image from a separate small lens, most often located above the main one, enters the viewfinder. There is also a difference from the usual camera device (soap dish), where an image is displayed on the screen that falls directly on the matrix.

In a typical DSLR device, light passes through a lens (1). Then it reaches the diaphragm, which adjusts its amount (2), then the light reaches the mirror in the device of the DSLR, is reflected and passes through the prism (4) to redirect it to the viewfinder (5). The information screen adds to the image Additional information frame and exposure (varies by camera model). At the moment when photographing takes place, the mirror of the camera device (6) rises, the camera shutter (7) opens. At this moment, the light falls directly on the camera matrix and the frame is exposed - photographing. Then the shutter closes, the mirror is lowered back, and the camera is ready for the next shot. It is necessary to understand that all this difficult process inside happens in a split second.

From the very creation of the first device of the camera, its basic scheme of operation has hardly changed. The light passes through the hole, is scaled, and hits the light-sensitive element inside the camera device. Whether it's a film camera or a DSLR digital camera. Consider the main differences reflex camera from not mirroring. As you might have guessed, the main difference is in the presence of a special mirror. This mirror allows the photographer to see in the viewfinder exactly the same picture that falls on the film or matrix.

The mechanism of operation of a digital camera is rather complicated for an unprepared reader, but still we will briefly describe it: before pressing the shutter button in SLR cameras, a mirror is located between the lens and the matrix, reflecting from which light enters the viewfinder. In non-mirrored 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, automatic focusing may occur. If you press the shutter button halfway (if such a mode is provided), all automatically selected shooting parameters (focusing, exposure metering, photo material sensitivity (ISO), etc.) are selected. When pressed fully, the frame is taken, and information is read from the matrix into the built-in memory of the camera (buffer). Then the received data is processed by the processor, taking into account the set parameters of 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, data is saved to a flash card without processing by a processor (dead pixel correction and lossless compression are possible). Since it takes enough time to write an image to a flash card a large number of time, many cameras allow you to shoot the next frame before the end of the recording of the previous one on the flash card, if there is free space in the buffer.

What is the difference between a DSLR and a film SLR?

1. The first difference is obvious: a DSLR uses electronics to record an image onto a memory card, while a film SLR device captures an image onto film.

2. The second difference between a digital and a film reflex camera is that most digital SLR cameras record an image on the surface of the matrix, which is smaller in area than a frame in a film reflex camera.

3. The digital camera device allows the photographer to see the image immediately after shooting.

4. Older film cameras do not require electrical power. They are completely mechanical. And digital SLR cameras need batteries or rechargeable batteries.

5. When shooting on film it is better to overexpose the frame a little, but for a digital camera it is better to underexpose the frame a little.

6. Regardless of whether a digital camera or a film camera, both types of photo cameras have great opportunities for changing lenses, remote controls, flashes, batteries and other accessories.

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 cameras, digital cameras) in most of their external features and controls repeat the models of film photographic equipment. The fundamental difference turns out to be in the "stuffing" of the device, in the technologies of fixation and subsequent processing of the image.

Basic elements of a digital camera

Matrix

The main element of any digital photo or video camera is a matrix, from which in the greatest [ 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 overwhelming majority of cases grouped into rows and columns.

In modern digital cameras, 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 because they are manufactured using standard semiconductor technology, but the noise of such sensors is usually much higher than that of CCDs. Therefore, at present most of the DSC models (with the exception of a number of professional and semi-professional "DSLRs" Canon, Nikon and Sony and others with special noise suppression circuits) are equipped with CCDs. The name CCD is a charge-coupled device, which reflects the way in which the electric charge is read by the method of shifting from one matrix element to another, gradually filling the buffer register. Further, the voltage is amplified and fed to the ADC (analog-to-digital converter), after which it is supplied in digital form to the camera processor for further processing.

Lens

Gate

Consumer digital cameras have an electronic equivalent of the shutter that is built into the sensor and does the same job as a mechanical one. In more expensive cameras, two shutters are built in, and the mechanical one is used to prevent light from reaching the sensor after the exposure time has expired, which avoids the appearance of halo artifacts, partially blooming and smearing.

In some digital cameras, pressing the shutter button halfway triggers the automation systems. Autofocus and exposure control system fix the shooting parameters and wait for a full press. When you press the shutter button fully

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

• in a DSLR (with or without Live View):
  • the mirror rises and the “jumping” diaphragm is triggered,
  • the previously switched off matrix turns on,
  • the mechanical shutter opens for the duration of the exposure,
  • the mechanical shutter closes,
  • the mirror goes down and the diaphragm opens,
  • the frame is read and processed from the matrix.

Viewfinders

View in the viewfinder screen of the rangefinder camera.

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

CPU

The processors in digital cameras perform the following functions:

• shutter control;
• lens control in automatic and manual shooting modes;
• selection of white balance, measurement of illumination of an object, determination of exposure pair, selection of color temperature, etc .;
• flash control;
• bracketing control - the possibility of continuous shooting (usually in a series of 3 or 10 frames) with different camera settings;
• control of special effects from the existing set (sepia, black and white shooting, 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 an information carrier that provides long-term storage of large-volume data, including images obtained by a digital camera.

In the early models of digital cameras, other storage media were also used, including miniature hard disks, floppy disks, recordable optical and magneto-optical disks, etc., up to audio cassettes (in the very first sample of an electronic camera from Kodak, which used analog processing methods and saving images).

Connectors and interfaces

An external interface for connecting to a general-purpose computer is available in almost all digital cameras. Today () the most common of these is USB. Also apply special types connectors 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 of the camera on the left or right. Less commonly, mainly on compact cameras, on the panel facing the photographer. Some digital cameras do not have a mode dial, and the selection of the shooting mode is made using buttons and menus.

Shutter button (shutter key)

Photo control that initiates the capture sequence. It is executed in the form of a button either on the upper end of the device (compact cameras), or on the front and side of the handle in SLR cameras. When pressed, the camera will shoot and process the frame. Many models have a 2-step pressure (when pressed halfway, autofocus and exposure compensation technologies are triggered, when fully pressed, the picture is taken.)

Menu control

Most digital cameras use a menu interface to configure settings.

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

In DSLR cameras, when Live View is off, only shooting parameters are displayed on the screen (if enabled). The same interface is present in some compact cameras, for example, in the Canon PowerShot G11 in Quick Shot mode (in this mode, sighting is possible only 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-mirrored 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, automatic focusing may occur.

If you press the shutter button halfway (if such a mode is provided), all automatically selected shooting parameters are selected (focusing, exposure metering, photo material sensitivity (ISO), etc.).

When pressed fully, information is read from the matrix to the built-in memory of the camera (buffer). Then the received data is processed by the processor, taking into account the set parameters of 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, data is saved to a flash card without processing by a processor (dead pixel correction and lossless compression are 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 a flash card, if there is free space in the buffer.

see also

• Red eye effect

Notes (edit)

Literature

• Nikon's Guide to Digital Photography with the D50 Digital Camera. - M .: "Nikon Corporation", 2007. - 137 p.

The camera was invented in 1861 to capture and store still images. Initially, in the device, they were fixed on special plates, and later on film. From the 70s of the 20th century, the intensive development of digital technology begins. Classic (film) photographic devices are gradually starting to fade into the background. Today they have practically been supplanted by digital cameras. These state-of-the-art devices provide high quality images. The most widely used are mirrorless, mirrorless and compact models. For those involved in the creation of photographs, it is recommended to use the first two types of products. At the same time, for this kind of activity, knowledge of the device of the camera and the principle of its operation is necessary.

The principle of operation of digital and film photographic devices is, in general, identical. Its highly simplified scheme can be represented as follows:

• after pressing the button, the shutter opens and the light reflected from the object enters the camera through the lens;
• as a result, a picture is formed on a photosensitive element (matrix or film) - photographing;
• the shutter closes, after which the unit is ready to take further pictures.

The whole described process of photographing takes place in a split second. Different models of photographic equipment due to their design features its detailed course differs.

Unlike film cameras, digital cameras use photoelectric method... Its essence lies in the fact that the luminous flux is converted into an electrical signal, which is then recorded on a data carrier (digital storage device).

The captured image is immediately available for viewing on the liquid crystal display, which is very convenient for evaluating the result. It can be saved on a computer or laptop for further viewing, storage, editing, transmission (for example, over the Internet) or printing on photo paper using a printer.

Basic elements of a digital camera

DSLR digital camera belongs to the most advanced group of photographic equipment in terms of design and functionality. On his example, it is convenient to consider the device of photographic devices as a whole. This is due to the fact that you can get acquainted with the structural elements that are found in other types of this technique.

The main parts of a DSLR digital photographic apparatus are:

• lens;
• matrix;
• diaphragm;
• gate;
• pentaprism;
• viewfinder;
• swivel and auxiliary mirrors;
• light-tight housing.

Detailed diagram of the structure of the camera is presented below. It can be seen from it that the considered main parts are directly involved in the image acquisition process.

Without the presence of additional parts, for example, a flash, memory card, rechargeable batteries, liquid crystal display, various sensors, it is also impossible to operate the camera and take high-quality photographs. But these structural elements are not directly related to the principle of functioning of photographic equipment.

Camera lens

The lens is an optical system that consists of lenses located inside the frame. They are glass or plastic (in cheap models of technology). The light flux passing through the lens is refracted and forms an image on the matrix. Good lenses produce sharp, clear images without distortion.

New lens models may be equipped with electronic circuits, controlling, for example, an optical stabilizer, aperture. But on older cameras, the electronics may not function.

The main characteristics of lenses are:

1. Aperture ratio- a parameter showing the relationship between the brightness of the object that is displayed and the illumination of the image obtained in the focal plane (on the matrix) using the optical system.
2. Focal length Is the distance in millimeters from the optical center of the lens to the focal plane (focus) mark where the sensor is located. The angle of view (field of view) of the optics and the size of the resulting image depend on it.
3. Zoom- the ability of the optical system to bring distant objects closer (to enlarge their image). It is determined by the ratio of focal lengths (maximum to minimum).
4. A kind of bayonet.

On the lens markings, usually the first number (or a pair of numbers) indicates the focal length, and the second (or a pair) indicates the aperture. The classification of lenses by focal length and angle of view is shown in the following photo. The standard type of optics is considered more versatile.

Important! The luminous efficiency of lenses depends on the aperture ratio. The larger it is, the better the photographic equipment and, accordingly, the more expensive it is. Optical system, which has a higher aperture, allows you to take pictures for more short exposures than with a lower given indicator.

Optics mount

Lenses are attached to the camera body using a bayonet mount. It is a special high precision connection (often of the standard type). Structurally, this fastening unit can be made in the form of a union nut equipped with slots, or protrusions on the frame with corresponding grooves on the body. There are product models where the bayonet connection is represented by a large thread with a short stroke.

The main characteristics of the bayonet are:

• diameter, which affects the aperture of the lens;
• the working distance (schematically shown in the photo below), which determines the range of working focal lengths.

Important! The flange focal lengths of the camera and lens must match. The ability to install optics directly depends on this. different systems through an adapter to a photographic device.

Diaphragm and its functions

The diaphragm is a mechanism designed to regulate the light flux entering the sensor of a digital camera. It is located between the lenses inside the lens.

Structurally, the part consists of a set of petals superimposed one on one (their usual number is from 2 to 20 pieces), which come in different shapes. The magnitude of their mutual shift relative to the base position determines the size of the resulting round (with full opening) or polygonal (with partial) holes. Due to the fact that the mechanism is opened and closed, the amount of incoming light changes. Expensive and high-quality optics are equipped with multi-leaf diaphragms.

The depth of field (depth of field of the imaged space) depends on the diameter of the aperture: the smaller the circle, the greater the depth of field. This relationship allows photographers to create various effects when shooting, for example, to separate an object from the background.

In addition to the indicators considered, the size of the aperture opening affects the following parameters of the resulting image:

• aberration(error or error in image transmission), the value of which is the smallest when the aperture is closed as much as possible;
• diffraction(bending around obstacles by light waves), which is expressed in a decrease in the ability of the optics to reproduce the image of objects that are located near (the indicator is called the lens resolution), while reducing the size of the light-transmitting hole;
• vignetting(a decrease in illumination occurring from the center of the image to its edges), which is most pronounced at the maximum aperture.

The aperture is usually denoted by the letter "f". The number next to it indicates the diameter of the hole. In this case, the smaller the number, the larger the hole size indicated by it. Diameter 2.8 is currently the maximum on most lenses. Diffraction with aberration is balanced at apertures from f / 8 to f / 11. In this case, the lens has the maximum resolution.

For SLR cameras of modern production, lenses are equipped with jumping type iris diaphragms. They close to the set value only at the immediate moment of shooting. To be able to estimate the depth of field of an image at a certain hole diameter, many DSLRs equipped with a repeater... It is a mechanism for the forced closing of the diaphragm to the operating value.

Work of mirrors

Light passing through the aperture hole hits the mirror. There the stream is divided into 2 parts. One of them goes to phase sensors (reflected from the auxiliary mirror), which are designed to determine whether or not the image is in focus. The focusing system then instructs the lenses to move. In doing so, they become so that the subject being shot is in focus. This self-tuning is called phase detection autofocus... It is one of the main advantages of DSLRs over mirrorless digital cameras. To see the mirror inside the case, you just need to remove the optics.

The second stream hits the focusing screen (frosted glass). Thanks to this, the photographer can immediately assess the depth of field of the future shot and focusing accuracy. A convex lens located above the focusing screen increases the size of the resulting image. The mirror retracts after pressing the trigger, allowing light to enter the matrix without obstruction.

A whole category of photographic equipment is represented by models with a fixed semitransparent mirror. Its use allows you to use autofocus not only when taking photos, but also during video shooting in the "Live View" mode. Continuous sighting is also possible.

Functions and types of shutters

After pressing the shutter, the shutter is also released, which is installed between the mirror and the matrix. Its purpose is to regulate access to the light matrix. The time the shutter is open is called shutter speed. During this time interval, the exposure process takes place.

There are two types of shutters on DSLRs:

• mechanical (most common);
• electronic (digital).

Structurally mechanical gates represents vertically or horizontally located 1 or 2 curtains opaque for the luminous flux. The main characteristics of such gates are speed and lag. The latter is understood as the speed of opening the shutters after the shutter is pressed.

The shutters open and close very quickly (in a split second) due to electromagnets or springs. Shutter speed is the amount of time it takes to get a photo after you press the shutter release. Mechanical valves have a trip limit. Exposures from about 1/8000 of a second are obtained using digital shutters.

Electronic shutter- this is not any separate device, but the principle of exposure control (the amount of incoming light) by the matrix. Exposure in this case is the time interval between its zeroing and the moment the information is read from it. The use of electronic shutters is characterized by the ability to achieve shorter exposures without the use of expensive mechanical analogs.

Models of photographic devices with a combination of electronic and mechanical types of shutters are considered more advanced. In this case, the first is used for short exposures, and the second for long exposures. Also, a mechanical shutter protects the matrix from dust.

The amount of light entering the camera, controlled by the aperture, and the shutter speed, are at the heart of the photography process. Due to the combination of these indicators in different options different effects are achieved by photographers.

Pentaprism and viewfinder

The light flux, passing through the focusing screen, enters the pentaprism. It consists from two mirrors... Initially, the image comes upside down from the swivel mirror. The pentaprism mirrors turn it over, giving the final picture in its normal form to the viewfinder.

The viewfinder is a device that allows the photographer to evaluate shots in advance. Its main characteristics are:

• lightness (depends on the quality and light transmission properties of the glasses from which it is made);
• size (area);
• coverage (in modern models reaches 96-100%).

Important! It is easier for the photographer to evaluate shots with larger viewfinders with lighter lenses. But they are installed only on models above the average level.

The scheme of the movement of the light flux in the viewfinder of the camera

SLR cameras can be equipped with the following types of viewfinders:

• optical;
• electronic;
• mirrored.

Optical viewfinders the most common. Such devices are a lens system located near the lens. Their advantage is the lack of energy consumption, and the disadvantage is some distortion of the image entering the frame.

Electronic devices Is a miniature liquid crystal display (LCD) screen. The image is transferred to it from the camera matrix. The EVF can be used even in strong sunlight because it is located inside the housing. But during operation, it consumes electricity

SLR viewfinders are considered the best, because they are able to provide the highest contrast, the quality of the contours of objects. Such devices have passed to digital photographic devices from film counterparts. The image seen by the photographer is formed by a rotating mirror.

Models exist without viewfinders. In them, the sighting of images by the photographer takes place using an LCD monitor. The disadvantage of such screens is that it is almost impossible to see anything on them in bright sunlight. Also, monitors may have low resolution.

DSLR digital camera matrix

A DSLR matrix is ​​an analog or digital-to-analog microcircuit with photosensors. The latter are photosensitive elements, which convert the energy of light into an electrical charge (proportional to the magnitude of the brightness of the illumination). In this way, the matrices convert the optical image into an analog signal or into digital data. Which then come along the chain converter-processor-memory card.

Important! A light filter is responsible for obtaining pictures in color. It is installed in front of the microcircuit.

The main characteristics of the matrices are:

• permission;
• the size;
• photosensitivity (ISO);
• the ratio between signal and noise (a cluster of randomly located points of different colors, the appearance of which is associated with a lack of illumination of objects).

Under resolution understand the number of light-sensitive elements in a part, measured in modern devices by megapixels (corresponds to a million photosensors). The larger their number, the better small details will be transferred to the photo.

From matrix size, measured diagonally, depends on the number of photons that it can capture, as well as the presence of noise in the resulting image. The larger this parameter, the better (less noise). The diagonal of a part in popular models of photographic equipment is 1 / 1.8 -1 / 3.2 inches.

Photosensitivity of matrices is in the range of 50-3200. Large values Sensitivity allow you to shoot in low light, for example, at dusk or at night. But this also increases the noise level. The optimal ISO level is considered to be between 50 and 400. Increasing the sensitivity is accompanied by an increase in noise.

In mirror photography, two types of matrices are widespread:

• full-frame (the same size as the frame of 35 mm film);
• truncated (with reduced diagonal).

Matrices differ from each other in formats, which are as follows:

• Full Frame - full frame (35x24mm);
• APS-H - matrices of professional cameras (29 × 19-24 × 16 mm);
• APS-C - used in consumer-grade models (23 x 15-18 x 12 mm).

Full-frame sensors are larger than truncated ones. They are equipped with professional camera models.

Image stabilization systems

Frames are blurred due to camera movement when taking pictures or hand shake. This phenomenon is combated by an Image Stabilizer (not available on all models). It is of three types:

• optical;
• with a movable matrix;
• electronic (digital).

The first is a lens unit mounted in the lens, which is controlled by special sensors. Systems with movable die(for example, "Anti-shake") suppose its fixation on a moving platform. They are considered to be less effective than optical stabilization.

Electronic vr(vibration suppressor) involves the transformation of only the picture by the processor. The digital stabilizer works with all lenses.

A brief description of the rest of the details of photographic equipment

The presence of a flash allows you to highlight objects in the foreground close to the photographer. Typically, these initially built-in devices are characterized by low power. For this reason, semi-professional and professional photographic devices are equipped with a connector that allows you to connect additional flash units.

The functions of the camera are expanded by the use of flashes capable of suppressing red eye effect. It is also convenient to have several of their main operating modes:

• automatic;
• forced;
• slow sync;
• no flash.

To take self-portraits or eliminate camera shake, use the self-timer... This device creates a time lag between pressing the shutter release and actually releasing it.

On a note! During long-term photography, it is recommended to power a number of DSLR models instead of rechargeable batteries using an adapter connected via a dc in connector. This is only possible if you have access to a 220 V network.

Camera processor performs the following functions:

• controls flash, camera interface, autofocus;
• calculates exposure;
• processes data from a matrix;
• adjusts sharpness, sensitivity, contrast, white balance, noise and a number of other picture parameters;
• saves an image on a memory card by compressing files;
• provides communication with external devices (for example, a computer).

When digital data is processed by a processor, it is stored in RAM. Removable media in the form of memory cards of various formats (for example, SecureDigital - SD) are used to permanently save information.

Thanks to the presence control buttons you can manually control various settings, for example: adjust the shutter speed with the aperture, set the sensor's photosensitivity, white balance. This allows you to control the entire process of photography, to create the desired effects.

Conclusion

DSLR cameras allow you to take high quality images due to the presence of large sensors. Therefore, they are used in their activities by professional photographers and amateurs who are seriously involved in photography. The most important factor in the popularity of SLR photography equipment is also interchangeable optics, which makes it possible to take photographs through a telescope, endoscope or microscope.

Date of publication: 27.11.2014

In this lesson, we will try to explain in an accessible way about how a 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. simple language... This article will help you choose a camera for your tasks, and in the future enjoy shooting.

How does a camera work?

Everyone knows what a camera is for. But how does it work? Knowing how your camera works will help you get quality images every time. 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 deal with the process of photography.

• Light is the most important thing in photography. It all starts with him. The word “photography” itself can be translated as “painting with light”, “light painting”. Light begins its journey from a source, such as the sun.
• Light falls on all objects around us. This is very important to remember: the camera does not take pictures of 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.
• Light reflected from an object passes through the camera lens.
• It is projected onto a light-sensitive sensor - a matrix. Previously, when there were no digital cameras, film was used instead of a matrix.

• The matrix consists of millions of light-sensitive elements. They capture light and transmit information about it already in in electronic format into 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 matrix

The matrix is ​​the heart modern camera... The quality of 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.

First, let's deal with the resolution. Matrix resolution is the number of its light-sensitive elements, pixels. The more there are, the more dots will make up the final photo. Today, the average matrix resolution 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 low: it is not sharp, not contrasting, it is drowning in digital noise - interference. The image quality depends not only on the resolution in megapixels, but also on the physical size of the matrix itself.

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

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

Large matrices give a gain not only in detail, but also in image quality when shooting at high sensitivities, with poor lighting... The fact is that on a sensor of a large area, it is possible to realize a larger size of the photosensitive elements themselves - pixels. For comparison: one light-sensitive element of the matrix of a modern full-frame device 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 best quality Images. At the same time, working with them has several nuances. The laws of optics are such that when working with large matrix we get a shallow depth of field in the photo. On the one hand, we can blur the background beautifully 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 an 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 sensor, the easier it is to get a frame with a large depth of field. That is why, when shooting with a smartphone or a compact camera, it is difficult to blur the background in the picture: the depth of field is too high, everything in the picture becomes clear. Let's compare two shots taken with the same shooting parameters, but on cameras with matrices of different sizes.

A shot taken by a compact camera with a small 2/3 "sensor. Almost all the figures were in the depth of field.

If you like a blurry background in your photos, if you are doing 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 to it directly depends 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. Therefore, when buying a full-frame interchangeable-lens camera, be prepared for a good lens to be of solid size and weight. If you want to use a full-frame camera and still have a compact lens, you will have to be content with not the most versatile and not the fastest lenses. But in cameras using smaller matrices, it is quite possible to use lenses that are lighter, more compact. Compare for yourself.

Types of cameras. 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. Camera in the phone

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 experience in photographing with a phone. In pursuit of compactness, these cameras are equipped with tiny sensors and simple lenses. We all know that pictures from a phone do not pretend to be of high quality, but such shooting does not require special skills, and the phone is always at hand. However, if you are planning more or less serious photography, it is worth considering 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. Almost every home has a compact camera. Their main advantage is their small size, low price, easy to use and sometimes 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 compact models with large sensors, even with full-frame ones. But these are rather specific and expensive devices.

Compact cameras have a non-interchangeable lens. As a rule, such cameras are equipped with a universal lens that allows you to shoot both with a wide viewing angle and take close-up photographs of objects that are far 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 photography as easy as possible. In English they are called “Point-and-shoot”, which can be translated into Russian as “pointed and removed”. Indeed, to shoot with such a device, it is enough to press only one button, the rest will be done by automation. But these devices are not always designed for shooting with manual settings. Sometimes not all settings can be adjusted manually, and if it is possible, then you have to look for them somewhere in the menu of the device, which slows down the process.

The so-called "hyperzums" ("superzums", "ultrazums") stand apart in the class of compacts. The Hyperzum is a compact camera equipped with a very large zoom lens. It can shoot both with a wide angle of view and take close-ups of very distant objects. Lenses with such a large zoom are relatively large, because of which the camera loses its compactness and is comparable in size, and often in price, with more advanced classes of cameras.

Who are compact cameras and hypersomals suitable for?

First of all, those for whom photography is not a hobby or a profession. For those who just take pictures and do not want to load their heads with some complicated settings. These cameras are ideal for light travel. They always have automatic modes, which will allow even a beginner to cope with them. Professional photographers sometimes choose the compact as a secondary, secondary camera.

SLR Cameras

The next type of cameras are DSLRs 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 almost to perfection, and only in the 21st century, a digital matrix came to replace the film.

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

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

SLR cameras are called system cameras for a reason. Choosing a DSLR from a particular manufacturer, we choose the system from the camera, lenses and accessories (for example, flashes). This is actively used by all professional photographers and advanced amateurs.

DSLR cameras always use matrices big size... 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 simply be shocked by the speed of its work. Fast autofocus and instant response to all the manipulations of the photographer - the property of any SLR.

The SLR camera is very quick to operate. Manufacturers pay great attention their design, because it is a professional tool. The device is comfortable to hold in hands, and almost any setting can be adjusted with one or two buttons without going into the menu.

Another advantage worth noting is the long battery life. 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 is the main consumer of energy) is not always under load, but only directly during the shooting, 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, traveling, or taking long walks.

Of the minuses of SLR cameras, it is perhaps 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 DSLR.

Who is a DSLR camera for?

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

Interchangeable-lens compact cameras or mirrorless cameras

This is a relatively recent type of cameras and the most actively developing. The manufacturers reasonably decided that if you equip an ordinary compact camera with interchangeable lenses and a high-quality matrix, you will get a very interesting thing. Mirrorless cameras combine most of the advantages of DSLRs and compacts. As already mentioned, mirrorless cameras have interchangeable lenses and are compact in size. At the same time, they allow you to make frames of very high quality. After all, they are equipped with relatively large matrices.

Mirrorless cameras are generally pretty fast to work with. 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 don't like the lack of an optical viewfinder. Among other disadvantages of mirrorless cameras, it is worth noting the rather short battery life.

Manufacturers in this class of cameras pay particular 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 cameras.

Who is a mirrorless camera for?

For those who want to receive high quality photos but doesn't want to lug around a bulky DSLR camera. It is convenient to take such a camera when traveling. However, if you are planning a trip without the ability to charge your camera, it is best to bring a set of spare batteries with you.

Medium format cameras and digital backs

There are cameras with an even larger sensor than full-frame DSLRs. For example, its size could 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” cameras. This name has remained since the days of film photography. In the film era, these cameras used wide film, much wider than usual. Such cameras are used then and now by some professional photographers to obtain 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 removable 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 too high operational efficiency. Another disadvantage of medium format cameras is the price comparable to the price of a new foreign car.

Konstantin Voronov

I have been doing professional photography for over 8 years. Field of activity - wedding, portrait, landscape photography. A journalist by education. Developed several courses for the online photography training service Fotoshkola.net. Lecturer leading master classes.

A digital camera is a modern tool that gives a good way to create bright and interesting photographs that can make a strong impression on a person. digital photos... But to unleash creativity, you need to know and be able to use a digital SLR camera.

Photo: A sectional view of a digital SLR camera and its components

Digital SLR device (basics)

Taking pictures with a digital SLR camera is great today. But to get an excellent result, you need to be at the "helm", which means to know digital camera device and control all its capabilities and the operation of its nodes.

Probably enough lyrics, let's get started. So what's in the black digital camera body? What is it digital camera device ?

In the photo: section - a diagram with a description of the main units, elements and mechanisms of a digital SLR camera

As I said earlier on the page about the elements and assemblies of film cameras, there are no fundamental differences between a digital camera and a film camera. Here are all the major parts of a digital camera:

Lens;

1. Diaphragm;

   Excerpt;

   Photo flash;

All the main elements and assemblies in the digital camera remained unchanged, only slightly underwent design changes. And the very shape of the camera body has remained unchanged for over 150 years. Yes, the digital camera has added a lot of modern knots- lotions that allow you to make pictures more beautiful.

A digital SLR camera is a camera created on all the basic principles of a single objective, SLR camera, which were previously used in film photography.

Digital cameras basically work in exactly the same way as film cameras, but unlike film, they use a photosensitive element - a digital storage device, a matrix and a processor for controlling elements aperture, shutter speed, flash, other units, etc.

These cameras are equipped with many additional functions (provided by microelectronics) that were previously impossible to use in film cameras.
Such is the influence of time!

DSLR shooting process

Before pressing the shutter button, you must look at the subject through the viewfinder or liquid crystal display, and what you see there (where you pointed the lens) will be photographed (recorded) by your digital camera, namely:

• When you press the shutter button, a certain amount of light beam passing through the lens hits the matrix (light-sensitive element) of the camera.
• The matrix "capturing" the light, forms a digital image, simultaneously processing and synthesizing information about the brightness, proportions and the number of colors transmitted by the luminous flux.
• The amount of light hitting the matrix determines the degree of opening or closing the aperture, and the time it takes for the light to illuminate the matrix determines the shutter speed.

Well that's all how a digital camera works in short.

- Matrix of a digital camera -

Digital cameras are made by various manufacturers, but they all use two common types. matrices:

1. Full frame;
2. Truncated;

Full-frame sensor camera

Truncated-matrix camera

As we can see in the photographs, the full-frame sensor is visually larger than the truncated one located in the camera.
High-end cameras use so-called full-frame matrices. These sensors are the same size as a single frame of 35 mm film on a film camera.

In the rest of the cameras, the so-called "soap boxes" use sensors of other sizes and they are called truncated matrices.

Digital camera matrix differs in formats:

• Full frame

FF Matrix
(35x24 mm.)

APS-H Matrix
(29x19 - 24x16 mm.)

APS-C Matrix
(23x15 - 18x12 mm.)

As you can see from the photographs, sensors with C and H indices are smaller than full-frame ones.
This abbreviation stands for:
FF - Full Frame translates as full frame

APS stands for Advanced Photo System and translates as “advanced photo system”.
Symbol H - High Definition (truncated High definition matrix with a crop factor K = 1.3 - 1.5).

Symbol C - Classic (classic truncated matrix with a crop factor K = 1.6 - 2.0).

How is the crop factor of your camera's sensor calculated?

Very simply, you need to divide the length of each side of the full-frame sensor by the crop factor of your camera's sensor and you will get the actual size of your camera's sensor.

In order to understand the difference between these matrices relative to each other, as well as to see how these matrices see the same frame from the same distance through the same camera lens, see the photo below.

In a word, from the photo above, you can understand that the full-frame sensor sees a "wide" frame, and the "cropped" sensors see the frame narrower.

In terms of image quality, the truncated matrices are absolutely not inferior to full-frame matrices. And in practice, many professional photographers use cameras with a truncated matrix. Cameras with a truncated matrix allow you to zoom in more (bring the subject closer by increasing it) than full-frame cameras - this is positive quality at portrait photography.

Advantages and disadvantages of full-frame sensors

Dignity

1. High frame detail due to a larger number of light-sensitive elements on a large-size matrix. On such matrices, the smallest details of the subject are seen much better than on a "cropped" matrix.
2. The large size of the viewfinder window, due to the mirror size larger than the size of the matrix itself.
3. Large size of one pixel located on the matrix (this makes the matrix more sensitive to the light flux).
4. High depth of field (this is ensured by the actual large size one pixel located on the matrix).
5. Preservation of a large percentage of the image to the frame (this applies to portrait photography).
6. The minimum amount of digital noise in the photo (this applies primarily to high values ISO).

disadvantages

1. The cost of the camera (full-frame cameras are much more expensive).
2. Difficulty shooting at remote distances (cameras with "cropped" matrices win here).
3. Heavy weight camera (this is mainly due to the large size and weight of lenses to full-format cameras).
4. Narrow specialization of shooting (this refers to the fact that full-frame cameras are designed mainly for shooting at close range, and for example cameras with "cropped" matrices having a crop factor of K = 1.5 are universal for shooting at close and long distances).
5. A large number of various assemblies of these cameras (According to statistics, a large number of mechanical and electronic assemblies require a more attentive attitude to technology).

Conclusion

From this short overview, we can draw the following conclusion:

1. The principle of operation of digital and film cameras is the same, the only difference is that the photosensitive element in old cameras was photographic film, and in digital cameras - an electronic sensor matrix and large quantity additional nodes.
2. The rest of the nodes involved in photography for both types of cameras work in exactly the same way.

Digital cameras are subdivided, like film cameras, into:

• Professional cameras.
• Amateur cameras.

Both types of cameras have the ability to change lenses (except for "soap boxes"), but due to the size of the installed matrix (for professional ones - full frame, and for classic (amateur) ones - truncated), the lenses are not replaceable, namely:

• lenses for a full-frame sensor are suitable for shooting on cameras with a truncated sensor.
• lenses designed for truncated-matrix cameras are not suitable for full-frame cameras.

You can achieve the perfect picture quality with both professional and classic (amateur) digital cameras. As they say, the most important thing is the desire to shoot well and a little work.

Which camera is better to choose (full-frame or with a crop factor) is up to you, depending on your tasks in photography. There is only one hint - if you plan to use the camera as a source of income, then of course the full-frame one. If you are just a fan of family photography, then of course a camera with a crop factor of the matrix and without additional elementary units.

This is a short overview Digital Camera Structure - Basic Items we'll probably finish. A more thorough and detailed description of the Design and assemblies of a digital SLR camera (continued) can be read in the next publications.

P.S. All photos in this article have been digitally pre-processed and framed in volumetric baguette photo frames. ART Studios Vector ... If you are interested in digital processing services and improving the quality of your images, you can familiarize yourself with the entire list of our services performed with images in the section our services by clicking on the button below. The catalog of our online baguette studio photo frames can be found in the section of the photo frame website by clicking on the appropriate button below.

You can view photos of various genres designed in our studio in the section of our site by going to the gallery of works by clicking on the necessary button below.