While traditional film cameras usually require you to move the lens - and your entire camera - closer to your subject in order to magnify it - this process is called optical zoom - digital cameras offer you the option of digital zoom (see the query "Digital Cameras"). Many digital cameras are equipped with digital and optical zoom, each of which will present its own advantages and disadvantages.
How optical zoom works
As the name suggests, optical zoom entails moving the camera lens closer to the subject you are photographing, with a millimeter difference in actual proximity, which corresponds to a more dramatic perception of proximity. The optical zoom of the image depends on the type digital camera that you have. If you are using a compact point-and-shoot camera, you control the optical zoom using a button or lever that is attached to the camera body. If you are using a digital SLR (DSLR) camera, you manually expand or retract the lens.
Optical zoom limitations
The main limitation of optical zoom is that cameras are limited in how far they can zoom. A conventional point-and-shoot camera, for example, can only zoom in on subjects three times, which is insufficient for photographing subjects that are far from the shooting location. Digital cameras are more versatile - an 18-300mm lens can bring objects several hundred meters closer - but the thing is that if your lens does not have enough optical zoom to photograph the desired subject, the subject will be small.
How does it work digital zoom
Digital zoom, on the other hand, is about “bloating” the image to make the objects appear larger — the camera does this after the shot. You can think of digital zoom as similarly cropping a photo - you essentially select a small portion of the field and then increase its size, just like the original field. The digital zoom allows you to increase the size at which subjects are captured, no matter how far away you were when you took the photo.
Limitations of digital zoom
The effectiveness of digital zoom depends on the megapixel resolution of your camera (see the query "camera prices") - in other words, how many dots or pixels it captures per inch. If your camera has a high megapixel resolution, digital zoom will make the area of your image that you want to highlight clearer and sharper. If the camera has a lower resolution, your digital zoom will produce a blurry image.
We all want the best in life - friends, books, cars or even cameras. But even the most better stuff can be disappointing - for example, if you live in a large mansion that you dreamed of since childhood, you understand that you do not need 5 bedrooms and 6 toilets. The same can happen with a camera - the highest values do not mean that you will enjoy the operation of the camera.
You need to know that there are no exact rules for buying a camera that gives the most best image... In the end, it all depends not only on the zoom and pixels, but also on the photographer and the subjects being photographed. But, of course, details and specifics also have great importance... For example, it is better to give preference to optical zoom than digital, because there is still a difference. You should also pay attention to the focal length of the lenses.
Focal length ("XX" mm) is the power at which the camera can focus on a subject, and optical zoom (read "X" x, for example 16x reads sixteenx zoom) is the magnification available to the camera. This means that if a lens has a long focal length, it has a narrow and small angle of view, and a short focal length implies a wider angle of view. To make it clearer, let's consider an example: let's say you buy a camera with a focal length of 35mm and a 10x optical zoom. This means that the minimum distance available to the camera is 35mm, and the maximum distance, thanks to the 10x zoom, will be 250mm. If you buy a camera with a shorter focal length, then you can take pictures with a wider angle of view. This is why it is very important when buying a camera to know what kind of pictures you will be taking.
To make it easier to decide which camera to buy, we offer you a set simple questions, by answering which, you will determine what kind of zoom you need.
Do you need a camera to take pictures of your loved ones and friends, for example, at birthdays or other parties? In this case, you do not need a large zoom - 2x or 3x will be enough. In fact, photographing large groups people, a wide viewing angle is more important to you than a large zoom. If you need to take photos close-up, it is better to get closer than zooming in, narrowing the perspective of the shot and distorting the image.
Would you like to shoot natural landscapes while hiking in the woods or mountains? To do high-quality pictures nature, you need to firmly hold the camera in your hands, avoiding distortion and blur. Therefore, for distant shots, you will need a 5x or 7x zoom. This will provide high-quality and even shots from a distance, without reducing the angle of view and retaining all the details.
Do you want to take pictures of small objects that are very far away, such as birds or? Then you need a really big zoom, for example 10x. If you are interested in objects, and not what surrounds them, then a camera with a narrow perspective with a 10x or 15x zoom is suitable for you - so you can take pictures of a lion's face or even a hawk's beak.
Where do you want to take photos - outdoors or indoors? If you are going to photograph more at home or in the office, then due to the lack of space, you will need a wide angle of view. In this case, a 2x-5x zoom camera will suit you. If you want to photograph outdoors, then a good angle of view will be provided to you, therefore, to photograph distant objects, you will need a large zoom - from 5x or more.
When you buy an expensive camera, it is important to know what and why you are spending your money. Knowing your needs and goals will help you get the right camera for you.
Choosing and buying a camera is not an easy and responsible business: not only do you need to take into account all the desired functions and characteristics of the device, but you also need to find such a device in a suitable price range. The most main mistake buyer - unquestioning relying on the words of the sales floor consultant. As you know, the main task of managers is to increase sales. For good advertising of a product, marketers go to various tricks, for example, indicate in the description of the device a huge zoom value, and they do not indicate which zoom (optical or digital), hoping for the incompetence of the buyer. To avoid all this and choose the optimal device, you should know in advance everything about the zoom function and the types of zoom.
What is zoom?
Zoom (zoom) is a special parameter of the lens of the photographic device that allows you to change the scale, thereby increasing remote objects... With its help, you can shoot stars from a distance, zoom and photograph even flowers in a window on the 9th floor, even tests military equipment and the departure of shells without any mental and physical harm.
The zoom depends on the focal length value. FR is the length of the segment from the middle of the lens to the matrix, i.e., the focus point. It is customary to mark it on the lens in millimeters, for example, a pair of digits 5.8-24 mm: the first digit is the FR on short end, and the second digit is the long-end FR. If we divide the number of the long FR by the number of the short one, we get the zoom value equal to four.
Digital zoom
Now that we know what zoom is, it's worth understanding its main varieties: digital and optical. Some cameras combine both types.
Digital zoom, when compared with optical, is a kind of fiction, because through its use you can get only a digital processing product, and not a really high-quality approximate object in the photo. Scaling occurs by stretching the central part of the photo with the program until it reaches the size of the original frame.
If the digital zoom ratio is large, the image can be enlarged with less quality loss, but if it is small, then the quality is lost irretrievably when enlarged. Already filled microfragments cannot be qualitatively improved, so such images become highly pixelated when enlarged.
Nevertheless, it is impossible to say unequivocally that using digital zoom, you can get only a low quality image, because the digital processing methodology does not stand still, but is constantly improving. In comparison with devices literally 7 years ago, the current processing programs of cameras are able to significantly increase images, and this is done so well that stretching is almost imperceptible.
If this zoom definitely does not satisfy your requirements, you can always either turn it off or change its value in the settings.
Optical zoom
Such a zoom is an enlargement of the image by using an eyepiece. By reducing the viewing angle, i.e. the focal length, the object in the photo is brought closer. The main advantage of optical zoom over digital is the fact that when the image is enlarged, the inter-pixel distance does not decrease, so the quality of the photo does not deteriorate.
The focal length range can be seen directly on the lens. Naturally, with the optical zoom, its highest possible value is preferable, especially since the industry is not standing still, literally "stamping" more and more advanced devices.
Superzums - record holders of zoom magnification
V present time the optical 10x zoom can surprise only an 80-year-old grandmother. Progress is evident, and the current generation is already free to enjoy compact cameras equipped with 50x zoom. This is evaluated not just as a breakthrough, but as a whole leap, a leap of generations. Indeed, what is digital zoom compared to optical superzoom? Compact cameras with such a zoom have already managed to compete with bulky sets of DSLRs and countless lenses for unsurpassed photo quality. professional photographers in the sweat of their brow they drag them to all the photo sessions. Naturally, such compact superzoom will not replace many of the specific "gadgets" of highly functional photographic equipment, however, in terms of mobility and ergonomics, they give them a head start.
Due to the fact that compacts already have a powerful zoom, the lens of such a camera does not need to be constantly removed / put on in order to find the most suitable one in a particular photo shoot, so that this prevents dust from entering the matrix.
Zoom is also present in camcorders. The most progressive option in this case will be the manual superzoom. Even in spite of the fact that a video camera with zoom is not a novelty nowadays, the presence of such a function in the device is a significant bonus.
Therefore, it is best to opt for an optical zoom unit or a super zoom compact. You already know what digital zoom is and what the quality of photo enlargement is. Zoom should not be the main reason for buying a device, it is better to buy good camera, providing for the possibility of changing the optics. In this case, if the desire or to have a high-speed zoom completely overwhelms you, you can always buy a suitable lens.
Pixel - (from the words picture element - an element of an image) is an elementary colored point, the combination of which forms an image.The sensor is made up of megapixels, or millions of pixels. The more of them, the higher the resolution of the camera. Modern cameras have matrices with a resolution of 4,6,8 and more megapixels. For example, for printing photos in 10x15 and 15x20 formats, a resolution of 4 or 6 megapixels is sufficient.
What is the matrix made of?
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 the brightness of the light is used, the picture is black and white. To make it colored, the cells are covered with colored filters. In most matrices, each pixel is covered with a red, blue or green filter, in accordance with color scheme RGB (red-green-blue). Only three colors are used, as these are the primary colors and all others are obtained by mixing them. The filter lets only rays of its own color into the cell.
The image obtained on the matrix consists only of red, blue and green pixels - this is the form in which RAW files are recorded (unprocessed format). To record JPEG and TIFF files, the camera analyzes the color values of adjacent cells and calculates the color of the pixels.
Usually cameras are 2, 4, 8, 16 microseconds. The aspect ratio of compact digital cameras is made with an aspect ratio of 4: 3, rarely 16: 9. In SLR digital cameras, matrices with an aspect ratio of 3: 2 are used. In the camera menu, the user can choose the aspect ratio from the options available in the camera, for example 16: 9, 3: 2, 4: 3, 1: 1, 4: 5. In this case, the frame will be cropped in height or width.
What is zoom? What types of zoom are there?
Zoom is the ability of a camera lens to magnify objects of photography several times. The number of times the camera can "zoom in" on the subject is called the zoom factor.If we are talking about a digital camera, then it is necessary to separate two terms: optical zoom and digital zoom.
Optical zoom- this is the image that the camera allows you to take with the help of optical lenses. In other words, it is a smooth transition from general plan to large without loss of quality (!). Optical zoom 3X - 4X means that the camera, by changing the focal length of the lenses, can "bring you closer" to the subject of photography 4 times.
Digital zoom just enlarges the fragment like it would do graphics editor... This does not add new pixels, but simply increases the size of the existing ones. Consequently, the image quality is lost. The picture will not reveal any new details. The same result can be obtained by enlarging this image on a computer using a graphic editor.
An example of fragments of a landscape obtained using optical and digital zoom.
Result:
Exposition
Exposure is a quantitative measure of the light energy incident on a photosensitive element, the result of the interaction of aperture and shutter speed parameters.The term is often used - exposure, during which shooting takes place. If the shutter speed and aperture values are set correctly, the frames will look natural and correspond to reality. The quality of the picture largely depends on the exposure - insufficient exposure (called underexposure by photographers) leads to poor development of details in the shadows, overexposure (overexposure) - to poor study of bright areas.
Excerpt
Exposure - the time of exposure to light on a sensitive material - a matrix (or film).This is the time during which the shutter of the camera remains open and light acts on the sensor. Shutter speed is measured in seconds. The shutter speed is also selected depending on the creative tasks of the photographer:
For stationary objects, the use of long exposures is justified, especially for night photography, when the maximum open aperture is not enough for a normal exposure.
It should be noted that with long exposures:
- moving objects are blurry;
- the camera will react to the slightest hand movements and displacement of the device, in these cases a tripod is required or fixed support for the camera.
Diaphragm
An aperture is a device in a lens that allows you to change the amount of light that hits the film.The diaphragm changes the diameter of the "hole", thereby adjusting the amount of light that illuminates the matrix. The diameter of the "hole" is characterized by the diaphragm number (in common use - the diaphragm).
For example, for portraits, choose a small f-number, 3.5. This allows you to sharpen the figure of the person and blur the background. For landscape photography, you need to choose a larger aperture - 4 or 5.6 or even 8 so that all objects in the frame are sharp.
Depth of field
Depth of field in imaged space is the distance between two planes in space within which objects in the image are perceived as clear and not blurry.By choosing the aperture, you can change the depth of field. Thus, various artistic effects can be created.
Depth-of-field control is used to accentuate a subject surrounded by other, secondary subjects. A traditional example is portraiture, when it is necessary to get a sharp face and blurred background... The shallow depth of field makes this effect easy to achieve. As reverse example you can bring landscape photography, where for a sharp transfer of details, both in the foreground and in the background, a maximum depth of field is needed.
An example of obtaining a different depth of field:
It should be noted that:
- The larger the f-number (the smaller the diaphragm opening), the more depth sharpness.
- The further from the lens the subject is, the deeper the depth of field.
- The shorter the focal length of the lens (the larger the angle of view of the lens), the greater the depth of field.
Focal length of the lens
Focal length is the distance between the film and the optical center of the lens at infinity. According to the ratio of the focal length and the diagonal of the frame, the lenses are divided into normal, short-focus, long-focus, as well as lenses with a variable focal length.
The short-focus lenses provide large viewing angles. Lenses with a long focal length provide telephoto lenses with small angles of view, but allow you to shoot distant objects with greater magnification than conventional lenses.
What is ISO?
ISO is a numeric parameter that controls sensitivity to light. The higher it is, the brighter and richer your photos will be.That is, the higher the ISO value, the less light and time it takes for the sensor to capture a frame without a flash. But (!) With an increase in the sensitivity of the matrix, the so-called noise (unpleasant graininess) increases. As the shutter speed increases, the picture may appear out of focus (starting at 1/60 sec).
In this example, the photographer has set different ISOs, all other things being equal.
| ISO = 50 | ISO = 400 |
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What is DPI and why 300 DPI?
There are two different concepts about image resolution.
1. The absolute resolution of the photo is the size of the image in pixels. If the camera has an 8 MegaPixel matrix, which forms an image with a pixel size of 3264 * 2448, then it will be written to the file with the same size 3264 * 2448. It is important to understand that if, after editing in any program, the image remains the same size, then its resolution will not change.
2. DPI (abbreviation for dots per inch) - a value that determines the number of dots (elements bitmap) per unit area (or unit length). This resolution determines how detailed your image will be when printed. That. real resolution in DPI is obtained only when printing, based on the paper size and the dimensions of the photo in dots. While the print settings are unknown, and the photo is on your computer, such a photo has no concept of DPI. It will only make sense when printed.
Let's look at some examples.
A 6 MegaPixel camera will give you a 3000 by 2000 pixel photo. Let's try to print a 3,000 by 2,000-pixel photo on a computer with a resolution of 300 DPI. Let's take into account that 1 inch is 2.54 cm. So at 300 DPI, there will be 300 pixels in each inch. Dividing the length 3000 by 300 gets the number of inches = 10. Translated into cm, we get a length of 25.4 cm. We will do the same with the width. (2000/300) * 2.54 = 16.9 cm. Our photo (3000 x 2000 pixels) when printed at 300 DPI will have a print size of 25.4 cm by 16.9 cm.
Let's take the opposite situation. You want to print a photograph of 4x6 inches (10x15 cm).
A photo with a size of 600x900 pixels (0.5 megapixel), will be printed with a resolution of 150dpi
A photo with a size of 1200x1800 pixels (2 megapixels), will be printed with a resolution of 300dpi
Photo with size 2400x3600 pixels (8 megapixel), will be printed with a resolution of 600dpi
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Where does the DPI entry in the file properties come from? The file properties record the recommended viewing resolution on the monitor. You can change this value to any other integer. In this case, no changes in the quality of the photo stored on your computer will occur. If you are asked for images in exactly 300 DPI, feel free to change this value in the file! This can be done in Photoshop and other editors.
What does the histogram stand for?
A histogram is a graph by which you can judge the brightness of a photo. In other words, this is a diagram of the distribution of the brightness of the image - from the darkest area to the brightest. The scale at the bottom is divided in proportion to the brightness levels: on the left it corresponds to the darkest areas of the image, and on the right - the lightest, with shades of gray between them. The number of pixels is plotted along the vertical scale. The histogram allows you to more accurately set the exposure.What format to shoot?
Some cameras allow you to select the format of your photos.RAW- internal digital camera format for image recording. Files of this format contain raw (or minimally processed) data, which avoids information loss.
Tiff(Tagget Image File Format) is an image format that saves images without losing quality. This format allows you to save data without compression, or it can use LZW compression, which ensures that the original data is completely preserved.
Zoom in cameras is an essential characteristic. This is not even a characteristic of the camera itself, but rather a parameter of the lens. It depends on the FR value (focal length). The focal length itself is expressed in millimeters, it determines the distance from the focal point (matrix) to the middle of the lens. If you take any lens and carefully consider what is written on it, you can find 2 values, for example: 5.8-24 mm. This pair of numbers denotes the focal length. V this case the focal length at the short end will be 5.8 mm, at the long end - 24 mm. If these two values are divided by each other, then we get the zoom value. Here 24 divided by 5.8 equals 4.
Zoom(aka zoom) is used for zoom lenses, so these two concepts are closely related to each other. Basically, zoom determines how many times the camera can magnify the subject. This is what most sales assistants tell the buyer. This is partly true, but you need to understand that the zoom value is far from the most important selection criterion, and it does not affect the quality of the resulting images in any way.
Optical zoom
Optical zoom is most commonly found on SLR or mirrorless cameras that use interchangeable lenses. It is a characteristic of the camera optics itself. Removing or approaching an object is carried out "by hand" due to the shift of the lenses in the lens, while other parameters of the camera do not change. Consequently, the optical zoom does not affect the quality of the captured images, which even allows you to take photos with close objects. good quality(sorry for the tautology).
Digital zoom
Digital zoom - this is how this parameter is indicated in the characteristics of the camera. The attitude to such a "zoom" is not always good, and this is quite fair. The digital zoom works like this: the camera processor cuts out the desired piece from the photo and stretches it to the full size of the matrix. In this case, there is no real magnification of the object. Rather, it is, but such an "increase" can be obtained in the paint program, simply by increasing the image by a certain percentage. The resolution of the cut piece will suffer from this, and the quality will also suffer.
Therefore, when it comes to zoom, it is more appropriate to talk about optical. It is often better to turn off the digital zoom in the camera settings.
However, sometimes there is no other choice, so you have to resort to using digital zoom to enlarge the desired subject.
Ultrasights
Now there are digital cameras with so-called ultrazoom or superzoom, if you like. The optical zoom parameter in them can reach 50x and even more.
The simplest example - Here the zoom reaches 60x. Easy to determine: focal length: 4.3-258mm (hence the value 60). There is such a device on this moment about $ 400.
From myself: I personally had such a camera for a long time. I had to take it back, because I smeared the pictures a lot. In inept hands, it is quite difficult for them to get high-quality detailed images, so I do not recommend it to beginners. The zoom is really impressive here!
Zoom, aperture and more
Focal length and, accordingly, zoom are closely related to factors such as aperture. The aperture value determines how much light will pass through the lens and hit the sensor. The more you zoom, the more lenses are used in the lens and the less light will hit the matrix. Consequently, quality will be lost.
In all lenses, next to the FR, the aperture parameter is indicated for each of the distances. If the FR parameter for two different cameras is the same, then it is better to choose a model where the aperture parameter will be higher. The quality of pictures on such a device will be better. If you take a compact camera with a zoom value of more than 4x, then here the aperture value will not be high and the quality of the photo will hardly please.
You can also often find cameras with the same value zoom, but with different focal lengths. For example, both devices have 3x zoom. In this case, the FR in one is equal to 70-210 mm, in the other - 18-55 mm. In this case, one device is used for landscape photography, the other for portraits. Although the zoom value is the same here, their purpose is completely different. Therefore, when choosing a camera, you should not be guided by the zoom parameter as a selection criterion.
