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Digital television is a modern technology of television broadcasting, which consists in the transmission of television sound and images using video encoding. The television familiar to all of us is called analog and it is gradually becoming history. Its main disadvantage is the instability of the signal in various interferences and the ability to view only a few television channels. The digital signal is anti-interference, so it provides high quality sound and picture. In addition, on the same frequency, instead of an analog channel, it can transmit several digital ones at once. Thus, viewers get the opportunity to watch a variety of channels: general format, entertainment, information, educational, children's, music, sports, broadcasting series and movies.

Benefits of Digital TV

According to the transmission method, digital television is divided into:

terrestrial television broadcasting in DVB-T2 and DVB-T modes;
satellite and cable TV.

Advantages of digital TV connection:

reducing the power of transmitters;
increasing the noise immunity of television signals;
improving the quality of picture and sound in TV receivers;
a significant increase in TV programs;
availability of interactive TV systems;
the presence of additional functions: "video on demand", "transmission recording", "to the beginning of the transmission", the choice of subtitles and language;
the ability to create an archive of programs, etc.

The antennas that are used to receive the signal also differ. When buying them, you need to take into account the range of the transmitting station, the conditions of direct visibility to the station, as well as the level of the transmitted signal. Thus, antennas with a suspension height of ten meters and a high gain, as well as indoor antennas, are considered effective. But usually the reception of the signal is successfully carried out on the antenna that the subscriber has been using for a long time.

So, if the issue with buying a set-top box and installing a decimeter antenna is resolved, then you can start connecting the "numbers" to your TV. To do this, connect the tuner to the TV according to the instructions that come with it. Then we connect an antenna to it and use the remote control to start the channel search procedure. The search can be carried out manually or in automatic mode (choose the one that suits you). After a few minutes, the result will appear on the screen. Note that it is quite simple to find out if your TV supports digital television. So, if it has the designation DVB-T2, then it receives terrestrial digital television; if DVB-S - then it receives satellite TV and DVB-C - cable.

Before installing digital television, be sure to find out where the transmitting signal tower is located. In her direction, you will need to direct the antenna. If an external antenna is used, then it must be securely mounted on the brackets.

In this issue, I'm going to start a "long-playing" topic about how a digital camera is arranged and how it works, what all sorts of buzzwords like "bracketing" and "exposure compensation" mean, and, most importantly, how to purposefully use all this.

In general, a digital camera is a device that allows you to receive images of objects in digital form. By and large, the difference between a conventional and a digital camera is only in the image receiver. In the first case, this is a photographic emulsion, which then requires chemical treatment. In the second - a special electronic sensor that converts the incident light into an electrical signal. This sensor is called a sensor or a matrix and really is a rectangular matrix of light-sensitive cells placed on a single semiconductor chip.

When light hits a matrix element, it generates an electrical signal proportional to the amount of light that has fallen. Then the signals (so far these are analog signals) from the matrix elements are read and converted into digital form by an analog-to-digital (ADC) converter. Further, the digital data is processed by the camera's processor (yes, it also has a processor) and stored in the form of, in fact, a picture.

So, the heart of any digital camera is the sensor. Now there are two main technologies for the production of sensors - CCD (CCD, charge coupled device - charge coupled device) and CMOS. In a CCD-matrix during exposure (that is, at the moment, in fact, photographing), a charge proportional to the intensity of the incident light accumulates in the photosensitive elements. When data is read, these charges are shifted from cell to cell until the entire matrix is read (in fact, reading occurs line by line). This process in popular literature like to be compared with the transfer of buckets of water along the chain. CCD matrices are produced using MOS technology and, in order to obtain a high-quality image, they require high uniformity of parameters over the entire area of the chip. Accordingly, they are quite expensive.

An alternative to CCDs are CMOS (that is, in Russian, CMOS) matrices. At its core, a CMOS sensor is quite similar to a random access memory chip - DRAM. Also a rectangular matrix, also capacitors, also a random access readout. Photodiodes are used as photosensitive elements in CMOS matrices. In general, CMOS sensors are much better suited for the production of today's well-developed manufacturing processes. In addition, among other things (higher packing density of elements, lower power consumption, lower price), this allows you to integrate related electronics onto a single chip with a matrix. True, until recently, CMOS could not compete with CCD in terms of quality, so, on the basis of CMOS sensors, mainly cheap devices like webcams were made. However, recently several large companies at once (in particular, such an industry monster as Kodak) have been developing technologies for the production of high-resolution and high-quality CMOS matrices. The first "serious" (three-megapixel digital SLR) CMOS camera - Canon EOS-D30 - appeared almost two years ago. And the Canon EOS 1Ds and Kodak Pro DCS-14n full-frame cameras, announced at the latest Photokina, finally demonstrated the potential of CMOS sensors. However, most cameras are still produced on the basis of CCD matrices.

Those who want to learn more about both technologies can start here www.eecg.toronto.edu/~kphang/ece1352f/papers/ng_CCD.pdf , and we'll move on.

The next moment - the elements of the matrix (of any of the types described above) perceive only the intensity of the incident light (that is, they give a black and white image). Where does color come from? To obtain a color image, a special light filter is located between the lens and the matrix, consisting of primary color cells (GRGB or CMYG) located above the corresponding pixels. Moreover, two pixels are used for green (in RGB, or one in CMY), since the eye is most sensitive to this color. The final color of a pixel in the picture in such a system is calculated taking into account the intensities of neighboring elements of different colors, so that as a result, each single-color pixel of the matrix corresponds to a colored pixel in the picture. Thus, the final picture is always interpolated to some extent (that is, it is calculated, and not obtained by directly photographing the object, which inevitably affects the quality of the small details of the picture). As for specific filters, in most cases a rectangular matrix GRGB (Bayer filter) is used.

There is also such a thing as SuperCCD, invented by Fuji Photo Film and used in Fuji cameras since 2000. The essence of this technology is that the pixels (and the filter elements - also GRGB) are arranged in a kind of diagonal matrix.

Moreover, the camera interpolates not only the colors of the pixels themselves, but also the colors of the dots located between them. Thus, Fuji cameras always indicate a resolution that is twice the number of physical (single-color) pixels, which is not true. However, Fuji's technology still turned out to be quite successful - most people who compared the quality of images from SuperCCD and conventional cameras agree that the image quality from SuperCCD corresponds to a conventional matrix with a resolution about 1.5 times greater than the physical resolution of SuperCCD. But not 2 times as stated by Fuji.

Finishing the conversation about filters, it's time to mention the third alternative sensor technology, namely Foveon X3. It was developed by Foveon and was announced this spring. The essence of the technology is the physical reading of all three colors for each pixel (in theory, the resolution of such a sensor will be equivalent to the resolution of a conventional sensor with three times as many pixels). In this case, to divide the incident light into color components, the property of silicon (from which the sensor is made) is used to transmit light with different wavelengths (that is, color) to different depths. In fact, each Foveon pixel is a three-layer structure, and the depth of the active elements corresponds to the maximum light transmission of silicon for primary colors (RGB). I think it's a very promising idea. At least in theory. Because in practice, the first announced camera based on Foveon X3 remains the only one so far. And its deliveries have not really begun yet. We wrote more about this technology in the sixth issue of the newspaper this year.

But back to the sensors. The main characteristic of any matrix, from the point of view of the end user, is its resolution - that is, the number of photosensitive elements. Most cameras are now made on the basis of matrices of 2-4 megapixels (million pixels). Naturally, the higher the resolution of the matrix, the more detailed picture you can get on it. Of course, the larger the matrix, the more expensive it is. But you always have to pay for quality. The resolution of the matrix and the size of the resulting image in pixels are directly related, for example, on a megapixel camera we will get a picture with a size of 1024x960 = 983040. It must be said that increasing the resolution of matrices is one of the main tasks that digital camera manufacturers are currently struggling with. Say, about three years ago, most mid-range cameras were equipped with megapixel matrices. Two years ago, this number increased to two megapixels. A year ago, it already became equal to three or four megapixels. Now, most of the latest camera models are equipped with sensors with a resolution of 4-5 megapixels. And there are already several semi-professional models equipped with matrices of more than 10 megapixels. Apparently, somewhere at this level the race will stop, since a picture from a 10-megapixel matrix approximately corresponds in detail to a picture taken on a standard 35mm film.

By the way, do not confuse the resolution of the matrix in the form in which we defined it above, and the resolution. The latter is defined as the ability of a camera to separate an image of two objects, and is usually measured from a snapshot of a streak target with a known distance between streaks. Resolution describes the properties of the entire optical system of the camera - that is, the sensor and the lens. In principle, resolution and resolution are related, but this connection is determined not only by the parameters of the matrix, but also by the quality of the optics used in the camera.

The next characteristic of a digital camera, directly related to the matrix, is sensitivity. Or, more precisely, light sensitivity. This parameter, as the name implies, describes the sensitivity of the matrix to incident light and, in principle, is completely analogous to the sensitivity of conventional photographic materials. For example, you can buy 100, 200, or 400 speed film at the store. In the same way, you can set the sensitivity of the matrix, but the advantage of a digital camera is that the sensitivity is set individually for each frame. Say, in bright sunlight, you can shoot with a sensitivity of 100 or 50, and for night shooting you can switch to 400 (and in some cameras even to 1400). Most digital cameras allow you to set standard sensitivity values - 50, 100, 200 and 400. In addition, the auto exposure system can change the sensitivity smoothly. Since the sensitivity is physically adjusted by changing the signal gain from the matrix, this is quite simple to implement in the camera.

Sensitivity is measured in ISO units (at least for digital cameras, they have already become the standard). You can see how they are converted to DIN and GOST units in the table.

GOST	8	11	32	65	90	180	250
ISO	9	12	35	70	100	200	300
DIN	10	11-20	16	19-20	21	24	25-26

However, adjustable sensitivity has its drawbacks. Since the properties of the matrix do not change physically, but simply amplify the existing signal, the image begins to show more and more noise inherent in any electronic device. This greatly reduces the working dynamic range of the camera, so at high sensitivity you will not get a good picture. A similar problem, by the way, can also be encountered at large exposures - any matrix makes noise, and over time, noise accumulates. Many cameras now implement special noise reduction algorithms for long exposures, but they tend to smooth the image and blur fine details. In general, you can’t argue against the laws of physics, but still the ability to adjust sensitivity is a big plus for digital cameras.

Konstantin AFANASIEV

After the transition of on-air broadcasting from the analog standard to digital, it became necessary to purchase special devices for older TVs. All modern models of TV receivers are equipped with an appropriate tuner. However, not everyone is ready to change their TV because of this. Knowing how a digital TV set-top box works and the features of choosing a device, you can buy an inexpensive and effective device.

Purpose of the device

Thanks to the digital TV set-top box, you can not only watch broadcasting in the new standard, but also significantly expand the capabilities of the TV receiver. There are a large number of models on sale, differing in cost and functionality. Among the main functions performed by the console, you can note:

Play media files from a USB flash drive.
Recording a TV broadcast in ts format to an external drive.
Possibility to stop live view.
Thanks to the TimeShift function, the broadcast of a TV program can be postponed.

Some budget modern TV models have much less functionality, although they are equipped with a DVB-T2 tuner. In such a situation, the prefix will be able to significantly expand its capabilities.

It should also be said about another type of tuners - Smart TV set-top boxes. They give users even more options.

These devices can work in one of two ways:

All files are stored on the built-in media; to run the necessary software, you must first install it.
Cloud services are used to store work information, and the device can only function when connected to the Internet.

The main advantage of Smart set-top boxes is the ability to access various resources on the Internet and display information on the TV screen.

Such tuners can be equipped with several slots for connecting memory cards at once, they support a large number of multimedia formats.

Criterias of choice

Admittedly, a digital TV set-top box is not the most complex consumer electronic appliance.

But even considering the relatively low cost of these devices, you need to make the right choice. There are several criteria that must be kept in mind when going to the store.

Broadcast standards

This question is the most important when choosing a device. Since Russia uses the DVB-T2 digital television standard, TV set-top box must support it. This is a universal solution that suits users of all regions of the country. In addition, the picture quality of DVB-T2 is better than that of DVB-T1.

Two more standards should also be noted - DVB-S and DVB-S2. They are used to broadcast satellite television. If the set-top box supports them, then the user can connect it to a satellite dish and broadcast the received signal directly to the TV without using a receiver.

Today, many cable TV providers use the DVB-C standard. This gives them the ability to encode the signal. To gain access to it, special modules are required. If the device will be used to receive cable television, then it must also support this standard.

Connection methods

If the tuner is purchased to work with an old TV, then it must have three tulip or RCA connectors. One of them is used to output the video signal, while the other two transmit sound in stereo. Most set-top boxes today are equipped with an HDMI connector. This is a modern standard used for the simultaneous transmission of video and audio signals.

The presence of USB ports suggests that the device can be used as a multimedia player. In addition, an external drive is connected to them for recording TV programs, if such a function is supported by the set-top box.

It is also worth paying attention to the end-to-end antenna output, thanks to which two TV receivers can be connected to the set-top box at once without the use of splitters.

Functionality

Since digital tuners are not only capable of receiving a signal of the required standard, it is worth getting acquainted with their useful functions. One of them is TimeShift (delayed viewing). Thanks to her, the broadcast of a TV show can be paused and not miss an interesting moment.

You should also pay attention to the Personal Video Recorder (PVR) option. With its help, you can record programs if it is not possible to watch them live. It is quite obvious that for this external storage required. Many modern set-top box models can be used as a multimedia player due to the support of popular formats. The TV guide function allows you to find out the weekly schedule for all available channels.

Popular consoles

You can find a large number of set-top boxes in retail chains, but it is sometimes quite difficult to give preference to one or another model, even if you know the selection criteria. After getting acquainted with the review of popular set-top boxes, it will be easier to make a decision.

Model Supra SDT-94

The device looks stylish and has a low cost.

The prefix provides the ability to record programs on a flash drive, as well as view multimedia content.

The device is connected to the TV using "tulips" or an HDMI cable. It should be noted that it is worth using the second option, since the picture quality will be much better.

Among the advantages of the model are:

Low cost.
Confident signal reception.
Ease of setup.
The presence of an HDMI connector.
Parental control feature.

If we talk about the shortcomings, then most often users note the not very good performance of the IR receiver.

To control the set-top box, you literally have to aim at it with the remote control. It is also worth noting the image jumps when connected to a TV using RCA connectors.

Device Oriel 963

A distinctive feature of the model is the ease of configuration. The prefix will be quickly dealt with by people who do not understand anything about electronic household appliances. It is also worth noting that the prefix has an aluminum body. Thanks to this, it not only looks stylish, but also does not overheat during operation.

You can connect not only a flash drive, but also an external HDD to the USB connector. The device has a built-in media player that handles all popular formats perfectly. Do not forget about the delayed viewing function, which is sometimes extremely necessary.

The model has the following advantages:

High sensitivity IR receiver.
The control buttons are located on the front panel.
Allows you to record desired TV programs.
Has many connectors.

The device has only one drawback - not the most convenient menu. Otherwise, there are no complaints about Oriel 963.

Device B-Color DC1302

The device is easy to use and does an excellent job of receiving a DVB-T2 signal. Support for AC3 audio format makes this model a real media player. The fact is that in large video files, sound is recorded using this codec. Control buttons located on the front panel will make working with the console even more convenient.

It should be noted that the B-Color DC 1302 has support for HD channels. The metal case is an excellent heatsink and prevents the set-top box from overheating during operation. Among the shortcomings, only a relatively short length of the power cord, as well as a slightly slower channel switching can be noted.

The choice of a device for watching digital TV largely depends on the individual needs of the user. Not every person will overpay for additional functions, because he is ready to limit himself to only the main one. Before going to the store, you should immediately decide for what purposes you plan to use the tuner, not counting the main purpose.

Modern cameras do everything themselves - to get a picture, the user just needs to press a button. But it's still interesting: by what magic does the picture get into the camera? We will try to explain the basic principles of digital cameras.

Main parts

Basically, the device of a digital camera repeats the design of an analog one. Their main difference is in the photosensitive element on which the image is formed: in analog cameras it is a film, in digital cameras it is a matrix. Light through the lens enters the matrix, where an image is formed, which is then stored in memory. Now we will analyze these processes in more detail.

The camera consists of two main parts - the body and the lens. The case contains a matrix, a shutter (mechanical or electronic, and sometimes both at once), a processor and controls. A lens, whether removable or built-in, is a group of lenses housed in a plastic or metal housing.

Where is the picture

The matrix consists of many light-sensitive cells - pixels. Each cell, when light hits it, generates an electrical signal proportional to the intensity of the light flux. Since only information about the brightness of the light is used, the picture is black and white, and in order for it to be color, you have to resort to various tricks. The cells are covered with color filters - in most matrices, each pixel is covered with a red, blue or green filter (only one!) In accordance with the well-known RGB (red-green-blue) color scheme. Why these particular colors? Because they are the main ones, and all the rest are obtained by mixing them and reducing or increasing their saturation.

On the matrix, the filters are arranged in groups of four, so that two greens have one blue and one red. This is done because the human eye is most sensitive to green. Light rays of different spectra have different wavelengths, so the filter only allows rays of its own color to pass into the cell. The resulting picture consists only of red, blue and green pixels - this is how RAW files (raw format) are recorded. To record JPEG and TIFF files, the camera's processor analyzes the color values of neighboring cells and calculates the color of the pixels. This processing process is called color interpolation, and it is extremely important for obtaining high-quality photographs.

This arrangement of filters on the matrix cells is called the Bayer pattern

There are two main types of matrices, and they differ in the way information is read from the sensor. In CCD-type matrices (CCD), information is read from cells sequentially, so file processing can take quite a long time. Although such sensors are "thoughtful", they are relatively cheap, and besides, the noise level in the images obtained with them is less.

CCD type

In matrices of the CMOS type (CMOS), information is read individually from each cell. Each pixel is marked with coordinates, which allows you to use the matrix for metering and autofocus.

CMOS sensor

The described types of matrices are single-layer, but there are also three-layer ones, where each cell simultaneously perceives three colors, distinguishing differently colored color streams by wavelength.

Three-layer matrix

The camera processor has already been mentioned above - it is responsible for all the processes that result in a picture. The processor determines the exposure parameters, decides which ones to apply in a given situation. The quality of photos and the speed of the camera depend on the processor and software.

At the click of the shutter

The shutter measures the amount of time that light hits the sensor (shutter speed). In the vast majority of cases, this time is measured in fractions of a second - as they say, and you won’t have time to blink. In digital SLR cameras, as in film cameras, the shutter consists of two opaque shutters that cover the sensor. Because of these shutters in digital SLRs, it is impossible to sight on the display - after all, the matrix is \u200b\u200bclosed and cannot transmit an image to the display.

In compact cameras, the matrix is not closed by the shutter, and therefore it is possible to compose the frame according to the display

When the shutter button is pressed, the shutters are driven by springs or electromagnets, allowing light to enter, and an image is formed on the sensor - this is how a mechanical shutter works. But there are also electronic shutters in digital cameras - they are used in compact cameras. An electronic shutter, unlike a mechanical one, cannot be felt by hand, it is, in general, virtual. The matrix of compact cameras is always open (which is why you can compose the picture while looking at the display, and not at the viewfinder), but when the shutter button is pressed, the frame is exposed for the specified exposure time, and then written to memory. Due to the fact that electronic shutters do not have shutters, their shutter speeds can be ultra-short.

Focus

As mentioned above, the matrix itself is often used for autofocusing. In general, there are two types of autofocus - active and passive.

For active autofocus, the camera needs a transmitter and receiver that work in the infrared region or with ultrasound. The ultrasonic system measures the distance to an object using echolocation of the reflected signal. Passive focusing is carried out according to the contrast assessment method. Some professional cameras combine both types of focusing.

In principle, the entire area of the matrix can be used for focusing, and this allows manufacturers to place dozens of focusing zones on it, as well as use a “floating” focus point, which the user himself can place anywhere he wants.

The fight against distortion

It is the lens that forms the image on the matrix. The lens consists of several lenses - three or more. One lens cannot create a perfect image - it will be distorted at the edges (this is called aberrations). Roughly speaking, the beam of light should go directly to the sensor, without being scattered along the way. To some extent, this is facilitated by the diaphragm - a round plate with a hole in the middle, consisting of several petals. But you can’t close the aperture too much - because of this, the amount of light falling on the sensor decreases (which is used when determining the desired exposure). If, however, several lenses with different characteristics are assembled in series, the distortions given by them together will be much less than the aberrations of each of them separately. The more lenses, the less aberration and the less light hits the sensor. After all, glass, no matter how transparent it may seem to us, does not transmit all the light - some part is scattered, something is reflected. In order for the lenses to let in as much light as possible, they are coated with a special anti-reflective coating. If you look at the camera lens, you will see that the surface of the lens shimmers like a rainbow - this is the antireflection coating.

The lenses are positioned inside the lens like this

One of the characteristics of the lens is aperture, the value of the maximum open aperture. It is indicated on the lens, for example, like this: 28/2, where 28 is the focal length, and 2 is the aperture. For a zoom lens, the marking looks like this: 14-45 / 3.5-5.8. Two aperture values are listed for zooms because they have different minimum apertures at wide and telephoto. That is, at different focal lengths, the aperture ratio will be different.

The focal length that is indicated on all lenses is the distance from the front lens to the light receiver (in this case, the matrix). The focal length determines the viewing angle of the lens and its, so to speak, range, that is, how far it “sees”. Wide-angle lenses move the image further away from our normal vision, while telephoto lenses zoom in and have a small angle of view.

The viewing angle of the lens depends not only on its focal length, but also on the diagonal of the light receiver. For 35 mm film cameras, a lens with a focal length of 50 mm is considered normal (that is, approximately corresponding to the viewing angle of the human eye). Lenses with a shorter focal length are "wide angles", with a longer focal length - "telephotos".

The left side of the lower inscription on the lens is the zoom focal length, the right side is the aperture

This is where the problem lies, due to which, next to the focal length of a digital camera lens, its equivalent for 35 mm is often indicated. The diagonal of the matrix is less than the diagonal of the 35 mm frame, and therefore it is necessary to "translate" the numbers into a more familiar equivalent. Due to the same increase in focal length in SLR cameras with "film" lenses, wide-angle shooting becomes almost impossible. An 18mm lens for a film camera is a super wide angle lens, but for a digital camera its equivalent focal length will be around 30mm or more. As for telephoto lenses, increasing their "range" is only in the hands of photographers, because a regular lens with a focal length of, say, 400 mm is quite expensive.

Viewfinder

In film cameras, you can only compose a shot using the viewfinder. Digital ones allow you to completely forget about it, since in most models it is more convenient to use the display for this. Some very compact cameras don't have a viewfinder at all, simply because there isn't room for it. The most important thing about a viewfinder is what you can see through it. For example, SLR cameras are so called just because of the design features of the viewfinder. The image through the lens through a system of mirrors is transmitted to the viewfinder, and thus the photographer sees the real area of the frame. During shooting, when the shutter opens, the mirror blocking it rises and transmits light to the sensitive sensor. Such designs, of course, do an excellent job with their tasks, but they take up quite a lot of space and therefore are completely inapplicable in compact cameras.

This is how the image through the system of mirrors enters the viewfinder of the SLR camera

Real vision optical viewfinders are used in compact cameras. This is, roughly speaking, a through hole in the camera body. Such a viewfinder does not take up much space, but its view does not correspond to what the lens “sees”. There are also pseudo-reflex cameras with electronic viewfinders. In such viewfinders, a small display is installed, the image on which is transmitted directly from the matrix - just like on an external display.

Flash

Flash, a pulsed light source, is known to be used to illuminate where the main light is not enough. Built-in flashes are usually not very powerful, but their momentum is enough to illuminate the foreground. On semi-professional and professional cameras, there is also a contact for connecting a much more powerful external flash, it is called a “hot shoe”.

These are, in general, the basic elements and principles of operation of a digital camera. Agree, when you know how the device works, it is easier to achieve a quality result.

Likbez: how a digital camera works

Main parts Anti-distortion

Main parts

Where is the picture

This arrangement of filters on the matrix cells is called the Bayer pattern

CCD type

In matrices of the CMOS type (CMOS), information is read individually from each cell. Each pixel is marked with coordinates, which allows you to use the matrix for metering and autofocus.

CMOS sensor

Three-layer matrix

At the click of the shutter

In compact cameras, the matrix is not closed by the shutter, and therefore it is possible to compose the frame according to the display

Focus

As mentioned above, the matrix itself is often used for autofocusing. In general, there are two types of autofocus - active and passive.

The fight against distortion

The lenses are positioned inside the lens like this

The left side of the lower inscription on the lens is the zoom focal length, the right side is the aperture

Viewfinder

The most important thing about a viewfinder is what you can see through it. For example, SLR cameras are so called just because of the design features of the viewfinder. The image through the lens through a system of mirrors is transmitted to the viewfinder, and thus the photographer sees the real area of the frame. During shooting, when the shutter opens, the mirror blocking it rises and transmits light to the sensitive sensor. Such designs, of course, do an excellent job with their tasks, but they take up quite a lot of space and therefore are completely inapplicable in compact cameras.

This is how the image through the system of mirrors enters the viewfinder of the SLR camera

There are also pseudo-reflex cameras with electronic viewfinders. In such viewfinders, a small display is installed, the image on which is transmitted directly from the matrix - just like on an external display.

Flash

These are, in general, the basic elements and principles of operation of a digital camera. Agree, when you know how the device works, it is easier to achieve a quality result.