Sensor
— CCD (CCD). Abbreviation for Charge-Coupled Device. In such sensors, information is read from the photosensitive element according to the “line at a time” principle — an electronic signal is output to the image processor in the form of separate lines (there is also a “frame at a time” variant). In general, such matrices have good characteristics, but they are more expensive than CMOS. In addition, they are poorly suited for some specific conditions — for example, shooting with point light sources in the frame — which is why you have to use various additional technologies in the camera, which also affect the cost.
— CMOS (CMOS). The main advantages of CMOS matrices are ease of manufacture, low cost and power consumption, more compact dimensions than those of CCDs, and the ability to transfer a number of functions (focus, exposure metering, etc.) directly to the sensor, thus reducing the dimensions of the camera. In addition, the camera processor can read the entire image from such a matrix at once (rather than line by line, as in CCD); this avoids distortion when shooting fast-moving objects. The main disadvantage of CMOS is the increased possibility of noise, especially at high ISO values.
— CMOS (CMOS) BSI. BSI is an abbreviation for the English phrase "Backside Illumination". This is the name of "inverted" CMOS sensors, the light on which does not penetrate from the side of the photodiodes, but from the back of the matrix (from the side of the subst
...rate). With this implementation, the photodiodes receive more light, since it is not blocked by other elements of the image sensor. As a result, back-illuminated sensors boast high light sensitivity, which allows you to create images of better quality with less noise when shooting in low light conditions. BSI CMOS sensors require less light to properly expose a photo. In production, back-illuminated sensors are more expensive than traditional CMOS sensors.
— LiveMOS. A variety of matrices made using the technology of metal oxide semiconductors (MOS, MOS — Metal-Oxide Semiconductor). Compared to CMOS sensors, it has a simplified design, which provides less tendency to overheat and, as a result, a lower noise level. It is well suited for the "live" viewing mode (viewing in real time) of the image from the matrix on the screen or in the camera's viewfinder, which is why it received the word "Live" in the title. They also feature high data transfer rates.Focal length
Focal length of the camera lens.
Focal length is such a distance between the camera matrix and the optical center of the lens, focused at infinity, at which a clear and sharp image is obtained on the matrix. For models with interchangeable lenses (
mirrorless cameras and MILC, see “Camera Type”), this parameter is indicated if the camera is supplied with a lens (“kit”); Let us recall that, if desired, optics with other characteristics can be installed on such a camera.
The longer the focal length, the smaller the viewing angle of the lens, the higher the degree of approximation and the larger the objects visible in the frame. Therefore, this parameter is one of the key for any lens and largely determines its application (specific examples are given below).
Most often in modern digital cameras, lenses with a variable focal length are used: such lenses are able to zoom in and out of the image (for more details, see "Optical Zoom"). For "DSLRs" and MILC, specialized optics with a constant focal length (fixed lenses) are produced. But in digital compacts, "fixes" are used extremely rarely, usually such a lens is a sign of a high-end model with specific characteristics.
It should be borne in mind that the actual focal length of the lens is usually given in the characteristics of the camera. And the viewing angles and the general purpose of the optics are determined not only by this parameter, but also
...by the size of the matrix with which the optics are used. The dependence looks like this: at the same viewing angles, a lens for a larger matrix will have a longer focal length than a lens for a small sensor. Accordingly, only cameras with the same sensor size can be directly compared with each other in terms of lens focal length. However, to facilitate comparisons in the characteristics, the so-called. EGF - focal length in 35 mm equivalent: this is the focal length that a lens for a full frame matrix having the same viewing angles would have. You can compare by EGF lenses for any matrix size. There are formulas that allow you to independently calculate the equivalent of 35 mm, they can be found in special sources.
If we talk about a specific specialization, then the EGF up to 18 mm corresponds to ultra-wide-angle fisheye lenses. Wide-angle is considered "fixed" optics with EGF up to 28 mm, as well as vario lenses with a minimum EGF up to 35 mm. Values up to 60mm correspond to "general purpose" optics, 50 - 135mm are considered optimal for shooting portraits, and higher focal lengths are found in telephoto lenses. More detailed information about the specifics of various focal lengths can be found in special sources.Optical zoom
The magnification factor provided by the camera by using the capabilities of the lens (namely, by changing its focal length). In models with interchangeable lenses (see “Camera type”), indicated for the complete lens, if available.
Note that in this case the magnification is indicated not relative to the image visible to the naked eye, but relative to the image produced by the lens at minimum magnification. For example, if the characteristics indicate an optical zoom of 3x, this means that at the maximum magnification, objects in the frame will be three times larger than at the minimum.
The degree of optical zoom is directly related to the range of focal lengths (see above). You can determine this degree by dividing the maximum focal length of the lens by the minimum, for example 360mm / 36mm=10x magnification.
To date, optical zoom provides the best "close" image quality and is considered to be superior to digital zoom (see below). This is due to the fact that with this format of work, the entire area of \u200b\u200bthe matrix is constantly involved, which allows you to fully use its capabilities. Therefore, even among low-cost models, devices without optical zoom are very rare.
Connection ports
— USB C. A universal USB interface that uses a Type C connector. USB ports themselves (all types) are used mainly for connecting the camera to a computer for copying footage, managing settings, updating firmware, etc. Specifically The Type C connector is comparable in size to earlier miniUSB and microUSB, but has a reversible design that allows the plug to be inserted in either direction. In addition, USB C often operates according to the USB 3.1 standard, which allows for connection speeds of up to 10 Gbps - a useful feature when copying large amounts of content.
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HDMI. A comprehensive digital interface that allows you to transmit video (including high resolution) and audio (up to multi-channel) over a single cable. The presence of such a port makes it possible to use the camera as a player: it can be directly connected to a TV, monitor, projector, etc. and view your footage on the big screen. In this case, broadcast capabilities can include not only video playback, but also demonstration of captured photos in slide show mode. HDMI inputs are present in most modern video equipment, and connection is usually not a problem.
Nowadays, there are several versions of the HDMI interface on the market:
- v 1.4. The oldest version currently relevant, released in 2009. However, it supports 3D video, is capable of working with resolutions up to 4096x2160 at a speed of 24 fps, and in Full HD resolution the frame rate can reach 120...fps. In addition to the original v.1.4, there are also improved modifications - v.1.4a and v.1.4b; they are similar in basic capabilities, in both cases the improvements affected mainly work with 3D content.
- v2.0. Significant HDMI update introduced in 2013. In this version, the maximum frame rate in 4K has increased to 60 fps, and support for ultra-wide 21:9 format can also be mentioned. In update v.2.0a, HDR support was added to the interface capabilities; in v.2.0b this function was improved and expanded.
- v 2.1. Despite the similarity in name to v.2.0, this version, released in 2017, was a very large-scale update. In particular, it added support for 8K and even 10 K at speeds up to 120 fps, and also further expanded the capabilities for working with HDR. This version was released with its own cable - HDMI Ultra High Speed; all features of v.2.1 are available only when using cables of this standard, although basic functions can be used with simpler cords.
— Headphone output. Audio output allows you to connect headphones to the camera. As a rule, it is represented by a classic 3.5 mm mini-jack. The presence of such a connector provides the ability to monitor sound during video recording in real time. This is especially important when filming interviews, vlogs and other similar projects.
— Microphone input. Specialized input for connecting an external microphone to the camera. External microphones are significantly superior to built-in microphones in sound quality. Firstly, they are not so sensitive to the camera’s “own” sounds - from buttons, control wheels, focus motors, etc. (and if the microphone uses a long wire and is not attached to the body, these sounds will not be heard at all). Secondly, external microphones themselves have more advanced characteristics. On the other hand, their use is justified mainly for professional video recording; therefore, the presence of a microphone input, as a rule, corresponds to advanced video recording capabilities
Viewfinder
The type of
viewfinder provided in the design of the camera.
A viewfinder is an eyepiece in which the photographer is able to see the image being shot, and in some cases additional information (the location of autofocus sensors, individual shooting parameters, etc.). Regardless of the type, viewfinders are useful in that they allow you to clearly see the image you are shooting, even in bright ambient light (which can cause displays to “blind”). Their disadvantages are the need to bring the camera close to the face, as well as the inconvenience when working with glasses (although the latter is partly offset by diopter correction in the viewfinder itself). The types of viewfinders can be as follows:
— Electronic. Such a viewfinder is a system of lenses with a small screen behind them. It is widely used in advanced cameras with non-replaceable lenses (see "Camera Type"), can be used in MILC cameras, and relatively recently full-fledged "
SLRs " have appeared (in particular, made according to the so-called "translucent mirror technology") equipped with electronic viewfinders. The advantage of such a viewfinder is that, in addition to the image itself, it can display a large amount of service information (for example, about shooting parameters); the main disadvantage is the need to supply power from the battery (although the power consumption of such a system is still much lower than that of an
...external display).
— Optical. In this case, an optical viewfinder means an independent system with its own eyepiece and lens, built into the camera body and directed parallel to the optical axis of the lens (mirror and prism systems are separated into separate categories). Such a system can be located both directly above the lens and in the corner of the body. The advantages of optical viewfinders are simplicity, low cost and compactness, due to the absence of a complex system of mirrors or prisms in the design. Such a viewfinder can be used in any non-reflex cameras (classic digital or MILC). The main disadvantage of this option is the mismatch between the position of its lens and the main lens of the camera (the so-called parallax effect); in most cases, this does not create inconvenience, but when shooting at close distances, you have to take an amendment (although there are camera models with viewfinders that automatically correct).
— Optical and electronic. A specific type of viewfinder that combines elements of both systems described above. Usually, such structures are based on an optical viewfinder, which provides for the possibility of projecting various service information onto a visible image. And in some models, the system can also be switched to a fully electronic mode, blocking the access of light through the optics and observing only the picture on the screen through the viewfinder.
— Optical (mirror). As the name implies, the design of such a viewfinder is based on a system of mirrors. Through this system, the real image perceived by the camera lens is fed into the viewfinder eyepiece (in other words, the photographer is actually looking directly through the lens). SLR viewfinders are used exclusively in cameras of the corresponding type (see above). Their advantages are the absence of the parallax effect and the ability to immediately evaluate a number of shooting parameters, such as depth of field, the effect of installed light filters, etc. The main disadvantage of reflex viewfinders is the need to raise the mirror at the time of shooting. This complicates and increases the cost of the design, makes it less reliable, and the operation of the mirror lifting mechanism can cause vibrations and the “stirring” effect.
— Optical (pentaprism). In fact, it is a kind of mirror viewfinder (see above), in which the role of a part of the mirrors is assigned to a pentaprism — a glass structure of a special shape. The action of the pentaprism is based on the effect of the so-called total internal reflection; it is believed that in this way it is possible to achieve a brighter and clearer image than when using classic mirrors. Other advantages and disadvantages are identical to conventional reflex viewfinders (see above). The pentaprism is widely used in mirror devices.
— Is absent. The complete absence of a viewfinder in the design of the camera; For sighting in such models, a display is used. This feature is typical mainly for digital compacts (see "Type of camera"). Firstly, the dimensions of the body of such models often do not allow for a viewfinder to be included in the design; secondly, the specifics of the use of such cameras is usually such that the display is quite enough for them, and sometimes it is even more preferable — for example, when shooting from a non-standard position (above your head, with your arm outstretched in front of you, etc.).Frame coverage
The ratio, expressed as a percentage, between the part of the image that the photographer sees in the viewfinder (see above) and the image actually captured by the camera when shooting. Most often it is specified as a percentage of the width and height of the frame, and not of the area.
Modern digital cameras quite often have viewfinders with a frame coverage of less than 100% - thus, not only the visible scene, but also some space beyond its edges gets into the frame. This creates some inconvenience - in particular, it may be necessary to crop the picture to ensure a pre-conceived composition. Therefore, a viewfinder with 100 percent coverage is still considered ideal. Some time ago, such systems were found mainly in premium cameras, but now, thanks to cheaper prices and advances in technology, they can be installed even in relatively inexpensive amateur compacts (see “Camera type”).
Shots per charge
The maximum number of photos that the camera can take on a single battery without recharging/replacing it. In fact, this number usually turns out to be less (sometimes quite noticeable) due to the fact that part of the charge is “eaten up” by the lens mechanics, using the display, changing settings through the menu, etc. Nevertheless, this parameter is a good indicator of the battery life of the device, and different models can be compared with each other.
