Focal length (35mm equivalent)
Focal length of a standard video camera lens in terms of a 35 mm full-frame sensor. This parameter is also called the "equivalent focal length" — EFL.
The focal length itself is the distance from the optical centre of the lens (when focus to infinity) to the sensor, at which the sharpest image is obtained on the sensor. It is one of the key characteristics of any lens, because. determines the viewing angles, the degree of approximation and, accordingly, the specifics of the use of optics. At the same time, it is impossible to compare different options in terms of the actual focal length: the laws of physics are such that with different sizes of sensors, the same focal length will give different viewing angles. Therefore, EFL was adopted as a universal characteristic and criterion for comparison. It can be described as the focal length that a 35mm lens with the same viewing angles would have.
The larger the focal length, the narrower the viewing angle will be and the higher the degree of approximation of the visible scene. Optics with EFL up to 18 mm belongs to the class of ultra wide-angle ("fisheye") and is used primarily to create artistic effects. Distances up to 40 mm correspond to "wide angles", 50 mm gives the same degree of approximation as that of the naked eye, the range of 70-100 mm is considered optimal for portrait shooting, and large values allow the use of optics already as a telephoto lens. Knowing these provisions, one can approximately...evaluate the capabilities of the lens and its suitability for certain tasks; there are more detailed recommendations, they are described in special sources.
Also note that modern video cameras are usually equipped with lenses with a variable focal length (zoom), which allows you to change the degree of approximation and viewing angle; see "Optical Zoom" for details.
Optical zoom
The degree (multiplicity) of image magnification provided by the operation of the lens system in the lens itself, without additional digital processing (see "Digital zoom"). Optical zoom involves changing the focal length (see above): the longer the focal length, the smaller the viewing angle and the larger the objects visible in the frame. And the zoom multiplicity corresponds to the ratio between the maximum and minimum value of this distance. For example, in a 24 – 120 mm system, this parameter will be 120/24 = 5x. However, it is not always appropriate to choose a
high zoom camcorder.
The advantage of optical zoom over digital zoom is, first of all, high image quality: regardless of the degree of zoom, the camera uses the entire effective area of the sensor. At the same time, zoom indicators can reach several tens of times, which is more than enough for camcorders of any class. Therefore, this format is the main one today; it is not used only in some models of pocket cameras (see "Features"), where it is not possible to install a large lens with a zoom lens.
For modern models, the value of this parameter at the level of 10 – 12x is considered standard.
Image stabilization
An image stabilization method provided in the design of a video camera. The stabilization function itself is designed to compensate for small camera shakes so that they are not noticeable in the image. This is especially true when shooting handheld, and in fact most modern models are designed specifically for such usage. According to the method of work, there are such options:
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Optical. A special mechanism with a system of gyroscopes and movable lenses, installed directly in the lens, is responsible for the operation of such stabilization systems. It introduces a correction for all tremors, vibrations, etc., and the “picture” falls on the already stabilized sensor. Optical systems are considered the most advanced and efficient, because. their work allows you to use the entire area of the sensor, fully exploit its capabilities and provide good image quality. Among the shortcomings, it is worth noting the increase in the cost and weight of the cameras, as well as a slight decrease in the reliability of the optics. At the same time, these moments are most often not critical, and stabilizers of this type can be used even in simple and inexpensive models.
— Electronic. Electronic stabilization is carried out due to the fact that not the entire area of the sensor, but only some of it, is involved in the formation of an image for a frame. Simply put, the camera electronics "takes into account" a certain area of the sensor and
...transfers the image from it into the frame; and at small displacements, this "area of attention" is also displaced, due to which the visible image remains motionless. The advantages of electronic systems are simplicity of design, lightness, compactness and high reliability; they can be used with even the simplest lenses installed in pocket cameras (see “Features”). Their main disadvantage is the need to reserve a part of the sensor, which reduces the size and resolution of the actually involved area and adversely affects the image quality.
— Optical / electronic. In such systems, both the methods described above are used — both the mechanism in the lens and the reserve on the sensor. This provides extremely high vibration compensation efficiency — the image remains stable even in such conditions in which any single method would be useless. On the other hand, the disadvantages of both options also remain relevant, and the cost of cameras with this feature is quite high.Number of megapixels
Effective resolution of the camera sensor when working in the photo shooting mode; in other words, the number of points or pixels that are directly involved in this mode (1 megapixel corresponds to a million points). The maximum size of a photo (see below) directly depends on this parameter: in fact, the number of megapixels corresponds to the size of the image vertically and horizontally, multiplied by each other. For example, a resolution of 3264x2456 corresponds to 8,016,384 pixels, or approximately 8.02 megapixels.
As with traditional digital photography, numerous megapixels allows you to get more detailed images with better visibility of fine details. However, as the resolution increases with the same sensor size, the size of each individual pixel and the amount of light falling on it decrease, which increases the likelihood of noise and generally reduces the quality of the picture.
Features
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Viewfinder. The presence of a viewfinder in the design of the camera — a special optical device in the form of a tube with an eyepiece and a small screen under it. Actually, the role of this device is similar to a conventional display: pointing the frame, controlling the shooting parameters, viewing the footage. The main difference is that in this case the screen is maximally covered and its visibility is almost independent of the ambient light conditions; this is very important in bright sunlight and in other similar situations where outdoor displays "become blind". In addition, the viewfinder can also be useful when stealth is important — it does not reflect on the operator's face and does not unmask it; and such systems consume less energy. On the other hand, the eyepiece during operation must be brought close to the eye; and if the external display allows you to hold the camera, for example, at arm's length above your head, then the viewfinder does not provide such freedom for manoeuvre. Also shooting through such a device can be quite tedious, especially for unaccustomed users; and viewfinders are poorly compatible with glasses. As a result, this element is found mainly in professional models of cameras (see "Features").
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Built-in flash. The presence of a flash in the camera — a light source for taking photos. The most popular use of a flash is to provide illumination in low light conditions;
...in addition, it can be used for shooting opposite to a bright light and some other special tasks. In cameras equipped with a backlight (see below), the same lamp can also act as a flash.
— Backlight lamp. The presence of its own lamp to illuminate insufficiently lit scenes in the design of the camera. This lamp differs from the flash described above as it is designed to work during video shooting and operates in constant light mode, and not in impulses. Backlight allows you to use the camera autonomously, without external lighting devices, which can not always be installed. However, do not forget that its operation also consumes battery power.
— Hot shoe. Hot shoe is a specialized mount for installing additional accessories. Most often it is used for external flashes, but not only: external viewfinders, microphones, GPS modules and much more can be attached to the hot shoe. There are several generally accepted standards for this mount, in addition, each manufacturer uses its own set of additional contacts to control advanced features of external equipment; this must be taken into account when selecting such equipment. However, if you intend to use external accessories, it makes sense to choose a camera with a hot shoe. Most of these models are professional (see "Features"), but there are exceptions.
— Built-in speaker. The presence of its own speaker in the camera design. This feature allows you to view footage with sound without the need for additional equipment such as headphones. Note that the quality of the built-in speakers is usually low, and they are not designed for more serious tasks (for example, playing music); and when viewing, they allow not so much to evaluate the quality of the audio, but to determine whether the sound was recorded.
— Built-in projector. The presence of its own projector in the camera design. This feature greatly simplifies the viewing of footage: it allows to provide a fairly large "picture" (with a diagonal of several tens of centimeters) using the camera itself, without the use of TVs or other external screens. However for viewing you will need a suitable surface — at least a plain light wall; but the power of the projectors themselves is low, and in bright light the image may not be visible at all. However, if the video needs to be shown to several viewers at once, this option is definitely more convenient than viewing it on the camera's own screen. In addition, you can watch any video uploaded to memory of a suitable format on the projector — in other words, use the camera as a player.
— Wi-Fi module. The camera has its own Wi-Fi wireless module. This standard is used to build computer networks, and more recently – also for direct communication between various devices: laptops, smartphones, tablets, etc. Specific options for using Wi-Fi may vary depending on the camera model, and include options such as direct copying of content to an external device or even to the Internet (such as YouTube), remote control of the camera, use as a webcam (see below). below), firmware update, etc. And all this is carried out without the use of wires, the communication range can reach 100 m, and the walls are not an obstacle (although they reduce the "range").
— NFC. The presence of a chip for NFC standard wireless communication in the camera. The range of such communication is up to 10 cm, and in cameras it plays an auxiliary role, facilitating the wireless connection of the camera and an external device (smartphone, tablet, etc.) that also has an NFC. Instead of digging through the settings, just bring both devices close to each other and confirm the Wi-Fi connection (see above). Accordingly, this chip is installed only in cameras that have more wireless capabilities.
— GPS module. The camera has a built-in GPS satellite navigation module. By itself, such a module during operation only captures the current location based on data from satellites, but how this data is used depends on the specific camera model. Most often, devices with GPS are able to at least add geotags to the footage — information about the geographical coordinates of the shooting location; but besides this, more extensive features can be provided — for example, search among the materials at the location of the shooting or even full-fledged navigation on the map.
— Detachable microphone. The presence of a mount in the design of the camera for installing an external removable microphone; the microphone itself can be included in the package or purchased separately. This function is typical for professional models and 3D cameras similar in functionality (see "Features") — it allows you to record sound of higher quality and with less noise than when using the built-in microphone.
— Webcam feature. The ability to connect the device to a computer and use it as a webcam — for video calls, broadcasting video directly to the Web, direct recording to a computer, etc. The advantage of camcorders over traditional webcams is the higher resolution and image quality. At the same time, this advantage has not been very noticeable lately, but larger size make camcorders less convenient; Therefore, this function is not widely used.
— Direct copy to HDD. The ability to connect an external hard drive directly to the camera and copy footage to it without using a computer. This feature is especially useful in situations where you need to make a copy (for example, to free up camera memory) and the computer is not nearby.
— Direct printing. The ability to connect the camera to a printer (to print captured photos) directly without using a computer. Software tools in such models can have quite extensive print management options: image selection, printing multiple copies, size and number of prints per sheet, print quality, error messages, etc. Typically, direct printing uses PictBridge technology using a USB connection. It must be supported not only by the camera, but also by the printer; at the same time, the connection does not require additional configuration, driver installation, etc.Battery type
Battery model name that is installed in the camera. This information will come in handy if you need to replace a failed battery, or buy a spare one. Note that some models can work not only with standart, but also with other batteries — for example, batteries with increased capacity; these moments and models of compatible batteries need to be specified according to the official documentation.
Battery capacity
The capacity of a regular camcorder battery is the amount of energy that it can hold on a full charge. In portable electronics, this parameter is measured in mAh; 1 mAh corresponds to the amount of energy that allows you to give a current of 1 mA for 1 hour. Of course, the higher the capacity, the longer the battery can last; however, keep in mind that the actual power consumption and battery life of modern cameras depends on a huge number of factors, ranging from the class (see "Features") to the specifications of individual electronic components. Therefore, in fact, the battery capacity is a purely reference characteristic, and it is impossible to compare different models with each other by it — for this you should use the directly claimed battery life (see below).
Battery life
The battery life of the camcorder from a fully charged standard battery. Usually, the specifications indicate the battery life in the recording mode, but in perfect conditions — without using additional features such as zoom, backlight, etc., which also “eat up” the charge. And if there is a viewfinder (see "Features"), the shooting time is usually indicated through this device, and not through an external display. Therefore, in fact, the battery life may be less, but in general, this parameter quite clearly describes the capabilities of a particular camera, and different models can be compared by it.
Note that for many cameras, in addition to regular ones, also “reinforced” batteries are produced, which allow increasing battery life by 2-3 times. Therefore, if you are not satisfied with the operating time in the selected model, it makes sense to ask about the availability of such batteries.