We are starting a series of publications about what a digital photo is, how a digital image is created and how it is saved. Kako you know the possibilities of digital shooting, about special modes and much more, which with the beginning of the era of digital photography every owner of a digital photo should know rovik" is simply necessary.
We need to start with the fact that the operating principles of digital photographic equipment are no different from analog (film) cameras. The three “pillars” on which photography rests: shutter speed (shutter speed), aperture, which creates exposure, and color temperature - these are the basic things that any photographer should know, regardless of what camera he has in his hands.
The differences begin with the way the captured image is constructed, that is, with the photosensitive element.
In a digital camera, the light-sensitive element is a photosensor - a device that converts light energy into the energy of an electrical charge and the brighter the light, the greater the charge. The image is projected onto a matrix, which is nothing more than several million photosensors arranged in rows and columns on an area no larger than a human fingernail. The information received from the photosensor is called an image element or simply a pixel. The same word is used to describe each photosensor on the matrix.
The pixel itself does not distinguish colors, but only registers the brightness of the incident light. A color image is formed as follows: a pixel-sized matrix of light filters is superimposed on the photosensor matrix. In a cluster of four pixels, one is covered in red, one is covered in blue, and two are covered in green (the two green ones simulate the human eye's increased sensitivity to green). Thus, a pixel covered with a red light filter measures the intensity of red, while others measure the intensity of blue and green, respectively. And from the combination of these three primary colors in the required proportion, the color of the miniature area of the image is obtained. Repeating the remaining sections gives a complete color image.
A CCD matrix is essentially a “charge-coupled device”; after illumination of the sensor, the resulting electrical signal is converted by a separate amplifier. It takes a fraction of a second to transfer information to it, which determines how many frames per second the camera can take.
How is an image recorded, where is it stored, and how important is the compression format and resolution in which the photograph was taken for the quality of the print?
From the electronic matrix, analog information received as a result of measuring the electric charge on photosensors is converted into binary format. Then it is recorded on a flash card, which is the carrier of information about the photograph taken. The map is a giant matrix of intersecting lines, each intersection storing one bit of information. When each value is written, it is assigned the value “0” or “1” and when they are read on the computer, an image is formed.
The quality of a digital image is determined by such important components as compression format and image resolution. The most common compression format is JPEG, which is used by all digital camera manufacturers. There are different levels of compression for this format, but with increasing compression, pixels that are not close in color and brightness fall into one series and hence, naturally, there is a loss in quality. The lossless compression format - RAW, is used to store images of the highest resolution - they take up a lot of space on a flash card, but this resolution is used, as a rule, only by professionals.
The maximum resolution in modern digital cameras is 2592 x 1944, but it should only be used when creating high-quality large-format photographs. If you are shooting for your own website, or making a digital album, then a resolution of 1024 x 768 will be enough for you. In general, if you print photographs of the most common sizes of 9 x 12 and 10 x 15, then a resolution of 1600 x is quite enough 1200.
As an example, we offer you a table of resolutions and compression levels corresponding to the quality for the Canon PowerShort G5 camera. The table indicates what the capacity of the flash card will be depending on the resolution of the recording format.
Card volume - 32 Mb. Type - Compact Flash.
As a rule, in digital cameras the photosensor is smaller in size than the frame on 35 mm film, so when comparing the sensor with the frame on film, you can see that with the same focal length of the lens, a smaller part of the scene being captured falls on the sensor.
Sensors in digital photography come in a wide variety of sizes, and with most users having experience shooting on 35mm film and with lenses of various focal lengths, it has become common to compare the field of view of a digital camera with the lens of a film camera. That is, if both an analog camera and a digital camera have a lens with the same focal length, then the angle of view of a 35 mm camera is wider than that of a digital one. And to obtain a similar image in a 35mm camera, you need a lens with a larger focal length than in a digital camera, which reduces the angle of view. For example, a digital camera lens with a 4mm focal length can fit a 28mm lens on a 35mm camera. This is written as follows: 4 mm (35 mm film equivalent: 28 mm).
One of the features of a digital camera is that in addition to optical zoom (zoom from English - zoom), they are equipped with digital zoom. And if optical zoom makes it possible to move the lens to a wide-angle position, then digital zoom increases the zoom range. Digital zooming enlarges the central part of the image to the size of the full frame and because the image is taken from fewer pixels, its resolution is reduced and the quality of the print will be lower than with optical zooming, but in any case, you will agree that additional capabilities are never superfluous :)
The key word in the photography process is exposure, which depends on two factors: the brightness of the light, as well as the duration of its impact on the matrix. The brightness of the light is regulated by the aperture, and the duration of exposure by shutter speed. Aperture is designated as the f/n ratio, with wide apertures corresponding to small numbers - f/2.8, f/2.0, and narrow apertures corresponding to large numbers - f/11, f/16. As a rule, digital cameras also have and fully automatic exposure mode. The camera in this mode automatically measures the light and sets the shutter speed and aperture to ensure correct exposure.
Various creative modes allow you to complement the automation. You can choose shutter speed with aperture priority and vice versa. But the greatest creative possibilities still open up when shooting manually, and here the most important advantage of any digital camera over an analog one is the ability to view the pictures taken on the LCD display. Although the image on the display is small, it is quite enough to evaluate how good the composition and exposure of the photograph turned out, and at the same time, as in a SLR camera, 100% of the image is reflected on the LCD display. In macro mode, it is also better to shoot using the LCD display. The LCD display also works in menu mode, which allows you to make all camera settings. You can erase failed images, which saves space on the flash card.
Before learning the basics of photography, you need to study to learn how the basic concepts of photography are put into practice.
First of all, it includes the camera body, also called “body” or “body” from the English word “body”.
This part of the camera contains the , which registers photographs, as well as the camera controls that the photographer uses to direct when and how to take photographs. The case also includes a battery, a built-in battery, an electronic display for viewing photos and other elements.
At the back of the camera there is a viewfinder through which the photographer sees the frame while taking photographs.
Some viewfinders rely on a mirror to allow you to see the scene through the lens (these are called TTL viewfinders). Other viewfinders are simply a hole in the camera body (common in point-and-shoot cameras). Thanks to the TTL viewfinder, the resulting image has exactly the boundaries that the photographer defined when shooting, so it is included in professional photographers and serious amateurs to ensure maximum image accuracy.
Shutter release
The shutter release is a special button that raises the shutter inside the camera to capture the shot. Camera device professional (mirror) also assumes that this button also raises a mirror, thanks to which the photographer sees what is happening through the lens. In most of these cameras, the shutter release can also be controlled remotely using a special cable or infrared port.
Gate
An opaque piece of metal or plastic inside the camera that protects the sensor or film from light. The shutter is raised using the release button, which is also included in the . The photographer clicks on it to capture the frame. The length of time the shutter remains open is controlled by shutter speed.
Shutter control
Shutter speed is a control that a photographer uses to tell the camera how long to open the shutter. In automatic cameras (soap cameras), the shutter speed is adjusted through a special menu, and its value is displayed on the display. In professional and semi-professional cameras, the shutter speed is adjusted using a special wheel on the camera body. Shutter speed is measured in fractions of a second, for example 1/60. The camera display usually only displays the denominator, for example, 60.
Light sensitivity control
Using ISO, the photographer adjusts the camera to work in different lighting conditions. Light sensitivity control is included as a menu item. In professional cameras it can be controlled using a separate button.
Aperture control
In automatic point-and-shoot cameras, the aperture is adjusted through the menu. In SLR cameras, you can control this parameter using a separate wheel or button. This setting controls the opening of the aperture, which is located inside the lens.
Matrix
The matrix is a key element included in . With its help, the camera registers photographs. The matrix is a light-sensitive material onto which an image is projected. The quality of photographs depends on the physical size of this element. The larger the matrix, the better the quality of the resulting images.
Flash
Most often it also includes a built-in flash. In point-and-shoot cameras, the flash is built into the camera body. In SLR cameras and some compact cameras it is placed above the camera on a special holder.
"Hot shoe"
- a mandatory element that is included in equipment used for professional purposes. This is a metal mount into which an external flash is inserted. The mount is called a hot shoe because it houses the electrical contacts and the flash fits into them like a foot into a shoe.
Lens ring (mount)
A lens ring is included which allows you to change lenses. This is the metal ring on the front of the camera that the lens attaches to. The ring contains electronic contacts through which shooting parameters are transmitted to the lens. On the side of the ring there is a special button, by pressing which the photographer can detach the lens from the camera body.
Lens
A lens is attached to the camera body through a mount - an element with which the image is projected onto the matrix. The following article describes in detail the design of a camera lens.
Man has always been drawn to beauty, the man tried to give shape to the beauty he saw. In poetry it was the form of a word, in music beauty had a harmonious sound basis, in painting the forms of beauty were conveyed in paints and colors. The only thing that man could not do was capture the moment. For example, catching a breaking drop of water or lightning cutting through a stormy sky. With the advent of the camera in history and the development of photography, this became possible. The history of photography knows of multiple attempts to invent the photographic process before the creation of the first photograph and dates back to the distant past, when mathematicians studying the optics of light refraction discovered that the image is reversed if it is passed into a dark room through a small hole.
In 1604, German astronomer Johannes Kepler established mathematical laws for the reflection of light in mirrors, which later formed the basis of the theory of lenses, according to which another Italian physicist Galileo Galilei created the first telescope for observing celestial bodies. The principle of refraction of rays had been established; all that remained was to learn how to somehow preserve the resulting images on prints by a chemical method that had not yet been discovered.
In the 1820s, Joseph Nicéphore Niépce discovered a way to preserve the resulting image by treating the incident light with asphalt varnish (analogous to bitumen) on a glass surface in the so-called camera obscura. With the help of asphalt varnish, the image took shape and became visible. For the first time in the history of mankind, a picture was drawn not by an artist, but by incident rays of light in refraction.
In 1835, the English physicist William Talbot, studying the capabilities of Niepce's camera obscura, was able to improve the quality of photographic images using a photographic print he invented - a negative. Thanks to this new feature, pictures could now be copied. In his first photograph, Talbot captured his own window, with the window grill clearly visible. In the future, he wrote a report where he called artistic photography the world of beauty, thus laying the future principle of printing photographs in the history of photography. 
In 1861, a photographer from England, T. Sutton, invented the first camera with a single reflex lens. The operating diagram of the first camera was as follows: a large box with a lid on top was attached to a tripod, through which light did not penetrate, but through which observation could be carried out. The lens caught the focus on the glass, where an image was formed using mirrors.
In 1889, the name of George Eastman Kodak was established in the history of photography, who patented the first photographic film in the form of a roll, and then the Kodak camera, designed specifically for photographic film. Subsequently, the name "Kodak" became the brand of the future large company. Interestingly, the name does not have a strong semantic load; in this case, Eastman decided to come up with a word that begins and ends with the same letter.
In 1904, the Lumiere brothers began producing color photo plates under the brand name "Lumiere", which became the founders of the future of color photography .
In 1923, the first camera appeared that used 35 mm film taken from cinema. Now it was possible to obtain small negatives, viewing them and then selecting the ones most suitable for printing large photographs. After 2 years, Leica cameras went into mass production.
In 1935, Leica 2 cameras were equipped with a separate video finder, a powerful focusing system, combining two images into one. A little later, in the new Leica 3 cameras, it becomes possible to use the shutter speed adjustment. For many years, Leica cameras have remained integral tools in the art of photography around the world.
In 1935, the Kodak company launched Kodakchrome color photographic films into mass production. But for a long time, when printing, they had to be sent for revision after development, where color components had already been applied during development.
In 1942, Kodak launched the production of Kodakcolor color photographic films, which over the next half century became one of the popular photographic films for professional and amateur cameras.
In 1963, the idea of fast photo printing was turned upside down by Polaroid cameras, where the photo was printed instantly after the photograph was taken with one click. It was enough just to wait a few minutes for the outlines of the images to begin to appear on the blank print, and then a full color photograph of good quality appeared. It would take another 30 years for Polaroid's versatile cameras to dominate the history of photography to give way to the era of digital photography.
In the 1970s cameras were equipped with a built-in exposure meter, autofocus, automatic shooting modes, amateur 35 mm cameras had a built-in flash. A little later, by the 80s, cameras began to be equipped with LCD panels that showed the user software settings and camera modes. The era of digital technology was just beginning.
In 1974, the first digital photograph of the starry sky was obtained using an electronic astronomical telescope.
In 1980, Sony was preparing to launch the Mavica digital video camera. The captured video was stored on a flexible floppy disk, which could be endlessly erased for a new recording.
In 1988, Fujifilm officially launched the first digital camera, the Fuji DS1P, where photographs were stored digitally on electronic media. The camera had 16Mb of internal memory.
In 1991, the Kodak company released the Kodak DCS10 digital SLR camera, which has a 1.3 mp resolution and a set of ready-made functions for professional digital photography.
In 1994, Canon equipped some of its camera models with an optical image stabilization system.
In 1995, Kodak, following Canon, stopped producing its branded film cameras, which had been popular for the last half century.
2000s Sony and Samsung corporations, rapidly developing on the basis of digital technologies, are absorbing most of the digital camera market. New amateur digital cameras quickly overcame the technological limit of 3 megapixels and, in terms of matrix size, easily compete with professional photographic equipment ranging in size from 7 to 12 megapixels. Despite the rapid development of technologies in digital technology, such as face recognition in the frame, correcting skin tones, eliminating red-eye, 28x zoom, automatic shooting scenes and even triggering the camera at the moment of a smile in the frame, the average price The market for digital cameras continues to decline, especially since in the amateur segment cameras have begun to be opposed by mobile phones equipped with built-in cameras with digital zoom. The demand for film cameras has fallen rapidly and now there is another trend of increasing prices for analog photography, which is becoming a rarity.
The operating principle of an analog camera: light passes through the lens aperture and, reacting with the chemical elements of the film, is stored on the film. Depending on the settings of the lens optics, the use of special lenses, the illumination and angle of directional light, and the opening time of the aperture, you can get a different type of image in the photograph. The artistic style of photography is formed from this and many other factors. Of course, the main criterion for evaluating a photograph remains the photographer’s eye and artistic taste.
Frame.
The camera body does not allow light to pass through, has mounts for the lens and flash, a conveniently shaped handle for gripping and a place for attaching to a tripod. A photographic film is placed inside the case, which is securely closed with a light-proof lid.
Film channel.
In it, the film is rewound, stopping at the frame needed for shooting. The counter is mechanically connected to the film channel, which, when scrolled, indicates the number of frames captured. There are motor-driven cameras that allow you to shoot at a sequentially specified period of time, as well as high-speed shooting up to several frames per second.
Viewfinder.
An optical lens through which the photographer sees the future frame in the frame. Often it has additional marks for determining the position of the object and some scales for adjusting the light and contrast.
Lens.
A lens is a powerful optical device consisting of several lenses that allows you to take images at different distances with changing focus. In addition to lenses, lenses for professional photography also consist of mirrors. A standard lens has a focal distance approximately equal to the frame diagonal, an angle of 45 degrees. The focal length of a wide-angle lens is shorter than the frame diagonal and is used for shooting in a small space, at an angle of up to 100 degrees. For distant and panoramic objects, a telescopic lens is used whose focal length is much greater than the diagonal of the frame.
Diaphragm.
A device that regulates the brightness of the optical image of the photographed object in relation to its brightness. The most widely used is the iris diaphragm, in which the light hole is formed by several crescent-shaped petals in the form of arcs; when shooting, the petals converge or diverge, reducing or increasing the diameter of the light hole.
Gate
The shutter of the camera opens the curtains to allow light to fall on the film, then the light begins to act on the film, entering into a chemical reaction. The exposure of the frame depends on how long the shutter is opened. So, for night photography, set a longer shutter speed; for shooting in the sun or high-speed photography, the shutter speed is as short as possible.
Rangefinder.
A device with which the photographer determines the distance to the subject. The rangefinder is often combined with the viewfinder for convenience.Release button.
Starts the photo taking process lasting no more than a second. In an instant, the shutter is released, the aperture blades open, light hits the chemical composition of the film, and the frame is captured. In older film cameras, the shutter button is based on a mechanical drive; in more modern cameras, the shutter button, like the rest of the moving elements of the camera, is electrically driven
Photo flash.
Poor illumination of photographic objects leads to the use of flash. In professional photography, this has to be resorted to only in urgent cases when there are no other screen lighting devices or lamps. The photographic flash consists of a gas-discharge lamp in the form of a glass tube containing xenon gas. As energy accumulates, the flash charges, the gas in the glass tube ionizes, then instantly discharges, creating a bright flash with a luminous intensity of over a hundred thousand candles. When using the flash, a red-eye effect is often observed in people and animals. This happens because when there is insufficient lighting in the room where photography is taking place, a person’s eyes widen and when the flash is fired, the pupils do not have time to contract, reflecting too much light from the eyeball. To eliminate the “red eye” effect, one of the methods is used to pre-direct the light flux to the person’s eyes before the flash is fired, which causes a narrowing of the pupil and less reflection of the flash light from it.
The principle of operation of a digital camera at the stage of light passing through the lens is the same as that of a film camera. The image is refracted through the optics system, but is not stored on the chemical element of the film in an analogue way, but is converted into digital information on a matrix, the resolution of which will determine the quality of the image. Then the recoded image is digitally stored on a removable storage medium. Information in the form of images can be edited, rewritten and sent to other storage media.
The body of a digital camera has a similar appearance to a film camera, but due to the absence of the need for a film channel and space for a reel of film, the body of a modern digital camera is much thinner than a conventional film camera and has room for an LCD screen built into the body or retractable, and slots for memory cards.
Viewfinder. Menu. Settings (LCD screen) .The liquid crystal screen is an integral part of a digital camera. It has a combined viewfinder function, in which you can zoom in on the subject, see the autofocus result, build exposure along the boundaries, and also use it as a menu screen with settings and options for a set of shooting functions.
Lens.In professional digital cameras, the lens is practically no different from analog cameras. It also consists of a lens and a set of mirrors and has the same mechanical functions. In amateur cameras, the lens has become much smaller and, in addition to optical zoom (bringing the object closer), has a built-in digital zoom, which can bring a distant object many times closer.
Matrix sensor.The main element of a digital camera is a small plate with conductors that forms image quality, the clarity of which depends on the resolution of the matrix.
Microprocessor.
Responsible for all functions of a digital camera. All camera control levers lead to a processor in which a software shell (firmware) is embedded, which is responsible for the camera’s actions: viewfinder operation, autofocus, program shooting scenes, settings and functions, electric drive of the retractable lens, flash operation.
Image stabilizer.
If you shake the camera while pressing the shutter release or take pictures from a moving surface, such as a boat bobbing on the waves, the image may become blurred. The optical stabilizer practically does not degrade the quality of the resulting image due to additional optics that compensate for image deviations when swaying, leaving the image motionless in front of the matrix. The way the camera's digital image stabilizer works when the image shakes is based on conditional corrections made when calculating the image by the processor, using an additional third of the pixels on the matrix that are involved only in image correction.
Information carriers.
The resulting image is stored in the camera’s memory as information on internal or external memory. The cameras have slots for memory cards SD, MMC, CF, XD-Picture, etc., as well as connectors for connecting to other sources of information storage: computer, HDD removable media, etc.
Digital photographic technology has greatly changed ideas in the history of photography about what an artistic photo should be. If in the old days a photographer had to go to various lengths to get an interesting color or an unusual focus to define the genre of a photograph, now there is a whole set of gadgets included in the digital camera software, adjusting the image size, changing the color, creating a frame around the photo. Also, any captured digital photograph can be edited in well-known photo editors on a computer and easily installed in a digital photo frame, which, following the step-by-step advance of digital technology, are becoming increasingly popular for decorating the interior with something new and unusual.
Digital photography tips for dummiesTips on digital photography for dummies.
Tips for shooting with a digital camera.
Lighting
Typically, digital cameras require better lighting than traditional film cameras. When photographing indoors, try to turn on as many lights as possible to ensure that your subject is sufficiently illuminated. For more natural colors, use sunlight with open curtains and blinds. Additional sunlight will improve the quality of your photos and make them brighter.
Learn to use flash, as shooting with a digital camera requires more light. Some cameras automatically turn on the flash, so you don't have to worry about setting it up. If your camera comes with a flash, take the time to consult a photo reference book. Adjusting the flash is necessary to avoid red-eye and improve the quality of your photography. Don't forget that the flash can be used both indoors and outdoors.
ADVICE: Using the flash increases power consumption. Always keep extra batteries with you as a backup when you plan to take a lot of pictures or go on vacation.
Shooting moving objects
A digital camera takes slightly longer to take a photo than a regular film camera. This doesn't matter if you're going to photograph a field of flowers, but if you want to capture your child's soccer team in action, the task will be more difficult.
ADVICE: Focus the camera just before your subject appears in the center of the viewfinder. When the subject just appears in the frame, release the shutter, so that when the camera finally fires, the moving subject will be completely in the frame.
Experiment!
Take lots of pictures. Since you're not paying for film, don't be afraid to take variations of the same photo in different modes and with different settings. The more photography techniques you learn, the more great photographs you will be able to take.
ADVICE: Try working with different compositions and lighting. Don't forget to take one or two extra memory cards.
If you've already taken photos with a digital camera or scanned images, it's time to transfer them to your computer. This can be done in different ways. Connect a cable between your computer and your digital camera, scanner, or memory card reader on your digital camera. This reliable method of transferring images to a computer has several advantages, as the speed of file transfer is simply remarkable. You won't have to waste time waiting until you can see the images being transferred.
When you take a digital photo or convert one you already have into a digital file, you should consider the following parameters:
.image resolution in pixels,
.file compression
.file format
Resolution in pixels.
A digital image is made up of small square dots called pixels. The pixels are the same size and each has its own color. By perceiving all the pixels together, the human eye recognizes the imaged object. TVs and monitors work on the same principle, illuminating thousands of small dots and thus creating an image on the screen.
All the pixels in the image create a visual image; the more pixels in the image, the more details can be distinguished, i.e. the higher the resolution. If you've ever seen a digital photo where you can see small squares, color holes, and ladders in the image, it was a low-resolution image.
Resolution is important for many reasons. You should consider not only the pixel resolution, but also the acceptable print size. Here are examples of resolution to print size ratios that ensure high-quality digital photo printing.
Less than 640 x 480 Half size photo print 10x15 cm.
640 x 480 Minimum acceptable resolution for 10x15 format (photo will not be of high enough quality)
1024 x 768 Minimum recommended resolution for 10x15 cm format.
1152 x 864 Minimum recommended resolution for 13x18 format
1600 x 1200 Minimum recommended resolution for 18x24 format
Another reason for choosing high resolution is simple: you can always reduce a digital image to a smaller size, but this process is irreversible. Why? When you enlarge a low-resolution image, it becomes blurry and unclear.
This happens because the computer "guesses" how many pixels and what colors to add to the image in the required order as the image size increases. This process is called "interpolation". The more pixels the computer has to reconstruct, the worse the image will be.
TIP: Always take a photo with the highest pixel resolution. If you wish, you can always reduce the image resolution after processing the photo.
File compression
When a digital camera or scanner captures an image, the file size can be quite large. Working with a photo or moving it over the Internet will not be easy.
To make it easier to work with large files, file compression is used. It occurs when a computer searches for similarities in digital images. The computer describes these similarities in abbreviated form by editing the file size. File compression can occur in different ways:
If your photo has a blue sky, then instead of describing every pixel of the blue sky, the compressed file can describe the sky in lines of 10 rows of the same blue color.
.Another way to reduce file size during compression is to reduce the number of colors in the digital image. If your photo shows a lot of green leaves, the computer will try to reduce the number of colors. This will group the different shades of color and replace them with one main green color.
.At times, file compression occurs automatically in digital cameras and scanners due to the fact that it allows for a better balance between quality and file size. When saving a file, you can choose between the file compression level or the image quality level. Most photographers are fine with quality 7 or 8 (with the maximum quality being 10).
TIP: If this is your first time saving a file, save it at the highest quality setting. The lower it is, the more information about the original image you will lose.
File formats
The abundance of digital file options can seem overwhelming. What is the difference between .jpg, .bmp, .tiff, .pict, .gif, and .eps? Are there advantages of one over the other? Are they interchangeable?
Experts can consider each and every merit of different file formats, but you are only interested in two features of each file format:
.whether compression is used or not (and image quality when compressed)
.purpose and use of digital files
For example, most Internet pages contain .gif or .jpg files. Your camera should save files in the formats that suit you:
.BMP No compression. Bitmap Represents each pixel separately, so the file is large.
.EPS No compression. Not widely distributed. Used for working with graphics in printing.
.GIF Compression is available. Mainly used for web graphics. Suitable for compressing images with a small number of colors (diagrams, graphs, logos)
.JPG Compression is available. The most common file type using image compression. Widely used both on the Internet, in digital photography and photo printing
.PSD Compression is available. Photoshop file. Can only be opened in Adobe Photoshop.
.TIFF Compression is available. A compressed file format that has an LZW compression option without loss of image quality.
If your digital camera saves images in a format other than .jpg, then you can use graphics programs that convert files to many image formats.
If you have an IBM-compatible computer and a Microsoft Windows system, then you can use the Paint utility, which is located in the Utilities folder, for conversion. If you have a Macintosh computer and Quicktime 4 installed, you can open digital files using Picture Viewer and convert them.
Many of us take simple photographs as our first experience. Even with the wide capabilities of a digital camera, if a mistake is made, most people prefer to take a second photo rather than correct an existing one. However, by sending your photos from your camera or scanner to your computer, you have plenty of opportunities to continue working on your digital images.
.Lightness of the image - perhaps your flash did not work, or, conversely, the photo is too bright. In these cases, you can adjust the light level and contrast of the photo.
.Focus Sharpness - If there is slight camera shake or when shooting a fast moving subject, the photo will end up slightly out of focus. To edit these photos, you can sharpen a slightly blurry image.
.Remove noise and scratches - When scanning photos, you often notice noise or scratches on the scanned image. The image editor will allow you to enlarge the image and, by highlighting the problem area, clear it of debris and thus improve the photo.
.Adding a frame or caption - In addition to editing photos, you can add an artistic frame around the photo or a caption on the back of the printed photo.
Photo editors.
There are a sufficient number of programs on sale that allow you to edit photos. Their capabilities are so wide that they make it possible to determine which image features need correction, what is important to you, and what you can do without. Therefore, before purchasing equipment, make sure that you are purchasing products that suit your needs. Many digital cameras and scanners already contain image editors. Check whether they are contained in the equipment you are going to buy.
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Lesson topic: “Digital information processing devices: digital video camera”
The purpose of the lesson:
create conditions for students to develop an understanding of the types and purposes of digital devices for information processing;
continue to develop skills in processing information using various devices;
continue to cultivate a caring attitude towards computer equipment, compliance with the rules of safe behavior in the office
DURING THE CLASSES:
1. Organizing time.
2.
Repetition of material from the previous lesson:
1) what device did we talk about in the last lesson?
2) What main elements of a camera can you name?
3) What are the advantages of digital cameras?
4) Where are the images stored in the camera?
5) How are images transferred from the camera?
3. Learning new material.
For today's lesson, you have prepared messages about digital video cameras - devices that greatly expand the capabilities of modern computers. We will get acquainted with this device according to the same plan as acquaintance with a digital camera, i.e.:
1 – main elements of a video camera
2 – advantages of digital video cameras
3 – devices for recording information in a video camera
4 - transferring information from the video camera to the computer
5– web cameras
Let's give the floor to representatives of the groups.
(students make messages and, if necessary, accompany the story with illustrations)
Material that can be offered to students is in Appendix 1.
4. Workshop on transferring video to a computer
Just like in the previous lesson, you can film fragments of students’ speeches and their activities during the lesson. In practice, show how to transfer video (as a last resort, from a camera). The form of work is individual.
5. Editing of a video about the study of Digital Information Processing Devices
Working with a video editor MoveMaker (front):
MoveMaker.2. Upload video images – Record video - Import video.
3. Upload Photo – Record Video - Import Images
4. Place video clips and photos on the storyboard panel (by dragging and dropping)
5. Add transitions: Edit a movie – View video transitions – Select a video transition – drag it to the storyboard panel in the area between frames.
6. Add effects: Film editing – View effects – Select an effect – drag it to the storyboard panel directly onto the frame. To enhance the effect, it can be used several times.
7. Adding titles and captions: Editing a film – Creating titles and captions – Select a title or caption effect – enter text, set formatting – click “Finish”.
8. Adding music: Record video - import sound and music - drag the fragment to the storyboard panel.
9. Saving a movie in the format WMV – Completing the creation of the movie – Saving the movie on your computer - Confirm the requests of the Save Movie Wizard.
Give this algorithm to students as a reminder. We all do the work together, the teacher shows the same thing on the screen.
6. Homework: In the next lesson, students will complete a film making project. To do this, they will have to think about the theme of the project, what fragments and photographs they will use. During the lesson they will have to film material and edit a short film. (The topics are varied: My school, My class, Our computer science classroom, Our teachers, etc.) Work is expected in groups of 2-3 people.
Appendix 1. Video cameras
Video cameras are primarily divided into digital and analogue. Here I will not consider analog cameras (VHS, S-VHS, VHS-C, Video-8, Hi-8) for obvious reasons. They have a place in a thrift store, or on the top shelf in a closet (what if someday they become a rarity), but analog video processing will definitely be considered, since, I think, everyone has a lot of cassettes. So, modern household video cameras differ in the type of video storage medium, in the method of recording (encoding) video information, in the size and number of matrices, and, of course, in optics.
1.1.1. Based on the type of storage media, cameras are divided into:
HDV cameras: the latest and, apparently, the main format in the future. Frame size up to 1920*1080. Imagine that each frame is a 2 megapixel photograph, and you will understand the quality of the video. Strictly speaking, HDV is a recording format, since there are HDD cameras that work in the HDV format. But I specifically put this format in this row, since most existing HDV cameras record on cassettes. If money is no object for you, these cameras are for you.
DV cameras: the main format of consumer digital video cameras. Frame size 720*576 (PAL) and 720*480 (NTSC). The recording quality largely depends on the optics and the quality (and quantity) of the matrices. DV cameras are divided into DV proper (mini-DV) cameras and Digital-8 cameras. Which one to buy depends on you, on the one hand, mini-DV cameras are more common, on the other hand, if you previously had a Video -8 camera, it makes sense to pay attention to Digital -8 cameras, since these cameras record freely on any format 8 cassettes (Video -8, Hi -8, Digital -8 (they can, of course, swear that Video -8 is a bit weak for me, but they write easily on them)), in addition, recording on better quality cassettes (Hi -8, Digital -8), you will get longer recording time compared to mini-DV.
DVD cameras. I'm not a fan of this type of camera. Their recording quality is lower than that of DV cameras, and even a disc with the best quality for them lasts about 20 minutes. But! If you are not picky about quality (especially since the difference is not so noticeable on an ordinary TV screen) and you do not want to bother with making a film and then encoding it into DVD format, you can easily use a DVD camera. Moreover, you can assemble a full-fledged DVD from the received files on a 1.4 GB DVD (used in DVD cameras) quite quickly using specialized programs (for example, CloneDVD and DVD-lab).
Flash cameras. Recording is done on a flash card in MPEG 4 and MPEG 2 formats. The duration depends on the size of the card, the selected frame size and the encoding quality. MPEG 2 is preferable because the quality is higher, but it takes up more space. But neither one nor the other format, when the camera processes video information for recording on a card, will be able to provide quality even slightly close to DV. Therefore, we can recommend such cameras as gifts for children or for filming in extreme conditions, since the undeniable advantage of these cameras is their compactness and the absence of mechanical parts (with the exception of a zoom lens).
HDD cameras. Recording is done to the built-in hard drive. Recording can be done in all formats from HDV to MPEG 4 (depending on the model). Perhaps, like flash cameras, this is the future of household video cameras, but unlike the latest HDD cameras, they can already provide excellent HDV quality, or up to 20 hours of recording of good quality MPEG 2 on a 30 GB disk. But let's look at this splendor from the other side, recording 1 hour of DV format takes up 13-14 Gb on the hard drive, and after making some simple calculations, say that it’s easier to rearrange the tape or copy the video to the computer after 2.3-3 hours of recording (to the good news) you get used to the quality quickly).
HDV cameras | High price |
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DV(miniDV) cameras |
| De facto standard for home video recording | The problem of choice, cheap point-and-shoot cameras and semi-professional models coexist peacefully in this standard |
DV(Digital-8) cameras | Recording and playback on any format 8 cassettes Longer recording per tape compared to miniDV | Low prevalence of the format |
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DVD cameras |
| I recorded it, took the disc out of the camera, and put it in the player. | Low recording quality Short disk write time |
Flash cameras |
| No mechanical parts (except for the zoom lens), resulting in higher reliability | Low recording quality |
HDD cameras | Much longer recording time compared to cassette machines High speed of rewriting information to the computer hard drive | Frequently downloading videos to the computer In the field, you need a laptop with a fairly large hard drive. High price |
1.1.2. Any digital video camera uses compression (compression) of digitized video, because at the moment there are simply no media capable of supporting uncompressed video (one minute of uncompressed PAL 720*576 video without sound takes up approximately 1.5 GB on the hard drive, simple calculations allow you to see that for one hour you will already need 90 GB). And this huge amount of information still needs to be processed; even a simple rewrite of 90 GB will take about five hours. Therefore, video camera manufacturers simply need to use digitized video compression. Modern video cameras use the following types of compression: DV, MPEG 2, MPEG 4 (DivX, XviD).
DV is the main type of video compression in modern digital video cameras; it is used by HDV, miniDV, Digital 8 and some HDD cameras. The high quality of this type of compression, I think, will remain leading among other formats for a long time.
MPEG 2 is a format used for recording DVDs. Although it has a slightly worse recording quality compared to DV, depending on the bitrate (roughly speaking, the number of bytes allocated per second of video), using this type of compression you can get fairly high quality video (remember licensed DVDs).
MPEG 4 – to be honest, manufacturers of digital equipment (photo and video) have seriously “tarnished” the reputation of this format. To “squeeze” everything possible out of this format, you need to use a fairly powerful computer and spend a decent amount of time. Therefore, it turns out that the final video in MPEG 4 format on video cameras and cameras is of low resolution and low (to put it mildly) quality. Whether DivX or XviD is used is not that important; the (small) difference, again, can only be seen when processing video on a computer.
1.1.3. An important, or rather the main, influence on the final result is the quality of the matrix used to digitize the optical signal passing through the lens of the video camera. The bigger it is, the better. When choosing a video camera, do not be lazy to look at the specification and see the number of effectively used pixels (“dots” on the matrix). For example, the specification for the Sony XXXXXXX video camera states that with a frame size of 720*576 (0.4 Megapixels), 2 Megapixels of the matrix are used for video. Naturally, this has the most positive effect on the final result, since with any encoding (compression) the law strictly applies: the better the source material, the better the result, and the more light that hits the matrix, the less digital noise there will be, the darker the time it will be possible to use a video camera, etc. All of the above in triple size applies to three-matrix cameras; among other things, the system of three matrices can significantly reduce color noise due to the fact that the division of light into RGB color components (a prerequisite for receiving a video signal) is not carried out electronics, but an optical prism, then each matrix processes its own color.
The size and quality of the matrix can be indirectly judged by the digital camera built into the video camera; the higher its resolution, the better.
1.1.4. With video camera optics, everything is simple: the more, the better. The larger the lens diameter, the more light will hit the sensor. The greater the optical magnification of the lens... However, this is worth dwelling on in more detail. The first thing I want to say is: NEVER look at the proud inscriptions on the side of the video camera (X120, X200, X400, etc.). You only need to look at the optical zoom of the lens (either on the camera (optical zoom) or on the lens itself). Of course, digital zoom can be used, but do not forget that digital zoom limits the number of effectively used matrix pixels (see figure). And just a 2x digital zoom (for example, with a 10x lens, this would be a 20x total magnification) will result in a 4x reduction in effectively used pixels on the sensor!
Well, it would be nice to have an optical stabilizer, since in cameras with a digital stabilizer not the entire area of the matrix is used.
Webcams
Webcams are inexpensive network stationary devices that transmit information, usually video, over wireless or cross-connected Internet and Ethernet channels. The main purpose of “room” webcams is to use them for working with video mail and teleconferencing. Such cameras are widely used in “babysitting” - they do an excellent job as video nannies, transmitting the image of a child left to his own devices. “Street” anti-vandal web cameras serve as security video monitors. The ability to capture images in video or camera mode is an additional feature of web cameras. In this case, you should not expect high quality from recorded videos or digital photos. Because there is no point in equipping webcams with high-quality optics and expensive electronics - transmitting video data in real time requires incredibly high compression, which inevitably leads to loss of image quality. Although it is fundamentally impossible to obtain a great picture using webcams, it is the quality of the resulting image that is the main characteristic that allows you to subjectively compare and select cameras of this type. However, preference can also be influenced by an interesting design, software package and various options such as support for skins and additional communication interfaces. All webcams are equipped with a motion detection function and an audio input that allows you to transmit audio information; they are also often equipped with connectors for connecting various external sensors and devices such as lighting and alarms. World practice shows that the main manufacturers of web cameras are companies that manufacture computer peripherals (Genius, Logitech, SavitMicro) or network equipment (D-Link, SavitMicro), and not video or photographic equipment, which once again emphasizes the difference in the technologies used.
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Video image compression formats
As an initial step in image processing, MPEG 1 and MPEG 2 compression formats split reference frames into several equal blocks, which are then subjected to diskette cosine transform (DCT). Compared to MPEG 1, the MPEG 2 compression format provides better image resolution at a higher video data rate through the use of new compression and redundant information removal algorithms, as well as encoding the output data stream. Also, the MPEG 2 compression format allows you to select the compression level due to the quantization accuracy. For video with a resolution of 352x288 pixels, the MPEG 1 compression format provides a transmission rate of 1.2 - 3 Mbit/s, and MPEG 2 - up to 4 Mbit/s.
Compared to MPEG 1, MPEG 2 compression format has the following advantages:
Like JPEG2000, MPEG 2 compression format allows scalability of different levels of image quality in a single video stream.
In the MPEG 2 compression format, the accuracy of motion vectors is increased to 1/2 pixel.
The user can select an arbitrary precision of the discrete cosine transform.
The MPEG 2 compression format includes additional prediction modes.
The MPEG 2 compression format was used by the now discontinued AXIS 250S video server from AXIS Communications, the 16-channel VR-716 video drive from JVC Professional, DVRs from FAST Video Security and many other video surveillance devices.
MPEG 4 compression format
MPEG4 uses so-called fractal image compression technology. Fractal (contour-based) compression involves extracting the contours and textures of objects from the image. Contours are presented in the form of so-called. splines (polynomial functions) and are encoded by reference points. Textures can be represented as coefficients of a spatial frequency transform (eg discrete cosine or wavelet transform).
The range of data transfer rates supported by the MPEG 4 video compression format is much wider than in MPEG 1 and MPEG 2. Further developments by specialists are aimed at completely replacing the processing methods used by the MPEG 2 format. The MPEG 4 video compression format supports a wide range of standards and data transfer rates. MPEG 4 includes progressive and interlace scanning techniques and supports arbitrary spatial resolutions and bit rates ranging from 5 kbps to 10 Mbps. MPEG 4 has an improved compression algorithm that improves quality and efficiency across all supported bit rates. Developed by JVC Professional, the VN-V25U webcam, part of the works line of network devices, uses the MPEG 4 compression format to process video images.
Video formats
The video format determines the structure of the video file, how the file is stored on a storage medium (CD, DVD, hard drive or communication channel). Usually different formats have different file extensions (*.avi, *. mpg, *.mov, etc.)
MPG - A video file that contains MPEG1 or MPEG2 encoded video.
As you noticed, MPEG-4 movies usually have the AVI extension. The AVI (Audi o-Video Interleaved) format was developed by Microsoft for storing and playing videos. It is a container that can contain anything from MPEG1 to MPEG4. It can contain streams of 4 types - Video, Audio, MIDI, Text. Moreover, there can be only one video stream, while there can be several audio streams. In particular, AVI can contain only one stream - either video or audio. The AVI format itself does not impose absolutely any restrictions on the type of codec used, neither for video nor for audio - they can be anything. Thus, AVI files can easily combine any video and audio codecs.
RealVideo format created by RealNetworks. RealVideo is used for live television broadcast on the Internet. For example, the television company CNN was one of the first to broadcast online. It has a small file size and the lowest quality, but without particularly loading your communication channel, you can watch the latest TV news on the website of the television company of your choice. Extensions RM, RA, RAM.
ASF - Streaming format from Microsoft.
WMV - Video file recorded in Windows Media format.
DAT - File copied from VCD(VideoCD)\SVCD disc. Contains MPEG1\2 video stream.
MOV - Apple Quicktime format.
Connecting to a PC or TV
The simplest connector - RCA AV output - simply put, “tulips” - is available in any video camera, is suitable for connecting to any television and video equipment, and provides analog video transmission with the greatest loss in quality. It is much more valuable to have such analog inputs in digital video cameras - this allows you to digitize your archives of analog recordings if you previously had a digital analog video camera. In digital format, their shelf life will be extended, and it will also be possible to edit them on a computer. Hi8, Super VHS (-C), mini-DV (DV) and Digital8 video cameras are equipped with an S-video connector, which, unlike RCA, transmits color and brightness signals separately, which significantly reduces losses and significantly improves image quality. The presence of an S-video input in digital models gives the same advantages to owners of archives of Hi 8 or Super VHS recordings. The built-in LaserLink infrared transmitter in Sony camcorders, using the IFT-R20 receiver, allows you to watch footage on TV without connecting to it with wires. Just place the video camera next to the TV at a distance of up to 3 m and turn on "PLAY". The more advanced Super LaserLink transmitter, which is equipped with all the latest models, operates at a greater distance (up to 7 m). The presence of editing connectors in the camcorder allows for linear editing by synchronizing the camcorder with VCRs and an editing deck. In this case, on all devices connected to each other, the tape counter readings and all main modes are synchronously monitored: playback, recording, stop, pause and rewind. In Panasonic camcorders, the Control-M connector is used for this purpose; in Sony camcorders, the Control-L (LANC) connector is used. Their specifications are incompatible, so we recommend checking the interface compatibility between the VCR and camcorder.
RS-232-C connector ("digital photo output")
A connector for connecting a video camera to a computer’s serial port for transmitting still frames in digital form and controlling the video camera from a PC. In “sophisticated” models, instead of RS-232-C, an even faster “photo output” is built in - a USB interface. All mini-DV and Digital8 camcorders are equipped with a DV output (i. LINK or IEEE 1394 or FireWire), providing fast transmission of digital audio/video signals without loss of quality. To do this, you need to have another device that supports the DV format - a DV video recorder or a computer with a DV card. More valuable, of course, are video cameras that, in addition to output, also have a DV input. Some companies produce the same model in two versions: the so-called. "European" (without inputs) and "Asian" (with inputs). This is explained by high customs duties in Europe on the import of digital video recorders, which rightly includes a video camera with a DV input. IEEE-1394, FireWire and i. LINK are three names for the same high-speed digital serial interface, which is used to transmit any type of digital information. IEEE-1394 (IEEE - Institute of Electrical and Electronics Engineers) Designation of an interface standard developed by Apple Corporation (under the trade name FireWire). The designation is adopted by the American Institute of Electrical and Electronics Engineers (IEEE). Most mini-DV and Digital8 camcorders are equipped with an IEEE-1394 interface, through which video information, presented in digital form, is sent directly to the computer. The hardware includes an inexpensive adapter and a four- or six-wire cable. Allows you to transfer data at speeds up to 400 Mbit/s.
i. LINK
Digital input/output based on the IEEE 1394 standard. Allows you to transfer video footage to a computer. Models of video cameras with i. Link add flexibility through interactive editing, electronic storage and distribution of images.
FireWire
Registered trademark of Apple, which took an active part in the development of the standard. The name FireWire (“fire wire”) belongs to Apple and can only be used to describe its products, and in relation to such devices on PCs it is customary to use the term IEEE-1394, that is, the name of the standard itself;
Memory card
On this card you can store photographs, videos, and music electronically. It can be used to transfer images to a computer.
Memory Stick
The Memory Stick memory card, a proprietary Sony development, is capable of simultaneously storing images, speech, music, graphics and text files. Weighing only 4 grams and the size of a stick of chewing gum, the memory card is reliable, has protection against accidental erasure, a 10-pin connection for greater reliability, data transfer frequency - 20 MHz, write speed - 1.5 MB / sec., read speed - 2.45 Mb/sec. Digital still image capacity on a 4 MB card (MSA-4A): in JPEG 640x480 format SuperFine - 20 frames, Fine - 40 frames, Standard - 60 frames; in JPEG 1152x864 format SuperFine - 6 frames, Fine - 12 frames, Standard - 18 frames. Capacity of MPEG Movies on a 4 MB card (MSA-4A): in Presentation mode (320x2.6 for 15 seconds; in Video Mail mode (160x1.6 for 60 seconds.
SD Memory Card
SD card - a new standard memory card the size of a postage stamp allows you to store any type of data, including a variety of photo, video and audio formats. SD cards are currently available in capacities of 64, 32, 16 and 8 MB. By the end of 2001, SD cards with a capacity of up to 256 MB will go on sale. One 64 MB SD card contains approximately the same amount of music as one CD. Since the data transfer speed to the SD card is 2 MB/sec, dubbing from a CD will take only 30 seconds. Since the SD Memory Card is a semiconductor storage medium, vibration does not have any effect on it, that is, there is no gap in sound, which is found in rotating media such as CD or MD. Maximum audio recording time on a 64 Mb SD card: 64 minutes of high quality (128 kbps), 86 minutes of standard (96 kbps) or 129 minutes in LP mode (64 kbps).
