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.
Aperture
Aperture of a standard video camera lens.
This parameter describes how much the lens attenuates the light output. Usually it is written as a ratio between the diameter of the active hole and the focal length of the lens, while the first value is taken as one and denoted as f — for example, f/1.8 or f/5.6. Moreover, the smaller the number in such a record, the higher the aperture ratio: for example, in our example, the first option is “lighter” than the second. Also note that most lenses with a variable focal length (see above) also have a variable aperture — in such cases it is indicated by the range from maximum to minimum (from a smaller number to a larger one).
A high aperture ratio is important primarily when shooting in low light conditions: it allows you to capture an image without “lifting up” the sensor sensitivity and without creating additional artifacts in the form of noise, and in the photo shooting mode, you can also work with shorter shutter speeds (which is useful for dynamic scenes). In addition, the higher the aperture, the lower the depth of field and the easier it is to get a blurry background. Note that for simple everyday tasks this parameter does not play a decisive role, but in professional shooting it can be very significant.
Digital zoom
The degree (multiplicity) of zoom provided by the camcorders due to software methods, without changing the focal length of the optics (see "Optical zoom"). The key principle of such an zoom is that part of the image from the sensor is "stretched" to the entire frame. This somewhat worsens the “picture” — after all, not all effective pixels take part in its formation; and the higher the zoom, the worse the quality becomes. On the other hand, this method does not depend on the specifications of the lens and works even with the simplest lenses that do not have zoom lenses, and it is much easier to achieve high magnification than with the optical method.
In modern camcorders, there are two options for using digital zoom. So, among pocket devices (see "Features"), it may be the only available option — not all of them are equipped with zoom lenses. And in full-size models, digital zoom usually complements optical zoom and turns on after the lens reaches the limit of its capabilities.
Note that when shooting 3D (see above), this feature may not be available, and in professional models it is often not used at all.
Recording formats
Video file formats that the camera can use to store recorded footage. If you want to view these materials using a separate device (player, media centre, etc.), you should make sure that this player supports the appropriate formats, otherwise conversion may be necessary.
Video recording speed
The data transfer speed provided by the camera when recording video. This parameter is also called bitrate (i.e., the number of bits per unit of time). For any file format used for recording, the general rule is that the higher the bitrate, the better the image quality (especially for formats that use lossy compression). On the other hand, high speed have appropriate requirements for the capabilities of the memory cards used — for more details, see "Memory card support"; and it increases the size of the file accordingly. Therefore, many modern camcorders are able to work with different bitrates; this allows you to choose the best option depending on what is more important for you at the moment — maximum quality or the ability to work with a slow card.
At the same time, we note that in terms of quality, this parameter is important mainly for professional video shooting. If you need a camera for amateur purposes, there is no need to look for the maximum bitrate: after all, such models (and memory cards for them) cost accordingly.
Shutter speed
The range of shutter speeds in which the camera is capable of operating during the shooting process.
Initially, shutter speed is the time during which light affects the photosensitive material (film) when shooting a single frame. For digital sensors, this is the period of time during which an image is read from the sensor to build a separate frame. When shooting video, this interval cannot be more than 1/n, where n is the frame rate (see above), but it can be less — for example, shooting at a frame rate of 30 fps and shutter speed of each frame 1/60 s. There are no such restrictions for the photo mode.
Long exposures are good because they allow the sensor to take in more light — accordingly, the “picture” is brighter, which is especially important in low light. At the same time, they increase the likelihood of getting a blurry image — due to the rapid movement of objects in the frame, the operator's hand shaking and other random camera movements that even the stabilization system is unable to compensate for. This effect can be useful for artistic motion blur, especially when shooting video, but in photo mode it is most often undesirable. Fast shutter speeds, on the other hand, allow you to get clear shots, but with less light, and in the case of video, even with the effect of sharp, jerky movements.
Accordingly, different exposure time options will be optimal for each situation, and the wider their range, the more opportunities the came...ra has to adjust to specific conditions.
Sound recording
The format in which the camera records sound during video recording. Typically, this section indicates the number of channels and the sound system used, the file format, or the characteristics of the audio stream, such as "2ch Dolby Digital (AC-3)" or "PCM, 16bit 48kHz, 2ch". In order not to go into technical details, we note that two channels are the minimum required for surround sound (stereo), and advanced models can work with multi-channel sound like 5.1. As for other specifications, you should pay attention to them when choosing a professional device (see "Features") — in amateur and especially pocket cameras, the sound format does not play a special role. Specific features of various formats are described in special sources.
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.Memory card support
Memory cards types supported by the camcorder. In modern devices, there may be such options:
— SD (SDHC, SDXC). The most popular memory card format for various electronics, including camcorders. The original SD standard allows you to create storages up to 4 GB, the next SDHC — up to 32 GB, and its successor SDXC — up to 2 TB. Reading devices under a certain standard are compatible with earlier versions of cards, but not vice versa: for example, a camera with SD HC support will be able to work with regular SD, but not with SD XC. These types of cards may correspond to different speed classes. These classes are described in more detail in special sources, but here we note that class 4 is considered the minimum suitable option for recording Full HD video. And anyway, the speed of the card should not be lower than the video recording speed provided by the video camera (see above) — otherwise the device just can't function properly. It is also worth mentioning that the rather large size of SD cards (32x24 mm) makes it difficult to use them in portable devices; to solve the problem, the microSD standard appeared (see below).
— microSD. in internal design such cards are completely similar to the SD cards described above and differ from them only in their reduced size — 15x11 mm. This allows them to be used even in the most compact modern devices, however, with equal volume, such cards are more expensive than their full-size counterparts, and the size of m...ost modern camcorders allow the use of conventional SD. Therefore, this option is found only where compact size is crucial — primarily among pocket models (see "Features"). microSD cards also have HC and XC modifications and are divided into speed classes; they can be used in SD card readers using the simplest adapters, and sometimes without them at all.
— MMC. A standard similar in many respects to SD — up to the fact that such cards are fully compatible with SD card readers in terms of size and contacts. MMC capacity — up to 64 GB, however, they work a little slower. Because of this, this standard is practically not used “in its pure form”, its support is usually combined with support for the more popular SD.
— MS (Memory Stick). The standard created by Sony is used mainly in the technology of this company, including camcorders. There are many varieties of such media, and not all of them are mutually compatible. MS cards are quite expensive and not as versatile as SD cards, so many cameras that support them can also work with SD.
— CompactFlash (CF). A standard originally created for professional photography; among video cameras, it is also used in professional models (see "Features"). CF cards have a good capacity (up to 128 GB) and high speed; their main disadvantage is their large size, which limits their use in compact technology. There are two CF formats — Type I and Type II; cards of the second type are faster, but do not fit the card readers of the first type due to their greater thickness.
— SxS. The standard, created by Sony and SanDisk specifically for professional camcorders and film cameras, is used in top-class devices. Such cards have high speed of work due to the fact that they use the connection according to the PCI Express standard; and their shape allows to install them directly into the ExpressCard slot on a computer or laptop. The maximum capacity of such media is 32 GB.
— P2. A company standard created by Panasonic exclusively for professional video recording. Inside, the P2 card is an array of 4 SD storages, and externally it is identical to a PCMCIA computer card and can be installed directly into the appropriate slot. The volume of such media is up to 64 GB.