Comparison Panasonic AG-UX180 vs Panasonic AG-UX90

The number of light sensitive pixels directly involved in the construction of the image. These are the dots on which the “image” projected by the lens onto the matrix falls. In addition to them, there are also service pixels that are not illuminated during camera operation — they provide auxiliary information necessary for processing the resulting image. Also, when calculating effective megapixels, the reserve area required for electronic stabilization is usually not taken into account (see "Image Stabilization").

The value of the number of effective pixels for different modes of operation of the camcorder will also be different. For example, when recording video, many cameras use multiple pixels to build a single dot on the image; this is due to the fact that the sensor resolutions significantly exceed those required for video shooting (for example, the Full HD standard technically corresponds to only 2.07 megapixels). As a result, the image quality depends more on the sensor size (see above) than on the resolution. And among sensors of the same size, high resolution allows user to get better colour rendering and higher clarity (however, not always — a lot also depends on the peculiarities of image processing). If we are talking about photography, then more megapixels means a higher resolution of the resulting image, but the quality of such a picture can be relatively low due to the increased noise level and low sensitivity of each individual pixel.

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.

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.

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:

— 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.

The maximum video resolution that the camera can capture. Resolution is the size of an image in points (pixels); usually it is written in two numbers, which correspond to the number of pixels horizontally and vertically.

The more pixels in the image — the clearer it is, the better you can see small details on it, however, the size of the video files increases accordingly. In addition, it is worth considering that in order to fully view the footage, you will need a screen of the appropriate resolution — otherwise all the advantages of the image will be negated. And this parameter also significantly affects the price of the device.

The smallest maximum resolution found in modern camcorders is about 720x480; the quality of such a "picture" can be compared with analogue television broadcasting. Resolution 1280x720 corresponds to the HD standard, it can be found among inexpensive TVs and monitors, and 1920x1080 (Full HD) is the most popular option among mid-range and top-class video devices. The maximum resolution used in modern consumer electronics (including camcorders) is 4K, 4096x2160; it is typical for the most advanced devices.

The vast majority of cameras are able to work not only with the maximum resolution, but also with several “more modest” options — for those cases where small file volumes are more important than high resolution.

The highest frame rate provided by the camera when shooting video. The minimum frequency for normal viewing is the classic 24 fps used in cinema. At the same time, most modern video cameras are capable of providing up to 50 – 60 fps, and even higher frequencies can be used for the slow motion effect.

In fact, this indicator is important primarily when shooting dynamic scenes. The higher the frame rate, the smoother the fast motion will look in the frame, the less jerky it will be and the more pleasant the overall impression of the image will be. The reverse side of this is an increase in the size of recorded files (all other things being equal). Therefore, the frame rate can be made adjustable so that the operator can choose the best option for a particular situation.

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.

The lowest illumination of the scene being shot, at which the camera is able to provide an image of normal quality. Note that in devices with a night view function (see below), this parameter can be specified in different ways. In some models, minimal illuminance is implied, in which the camera can shoot without backlight and at the same time maintain colour reproduction (as in normal daytime shooting); in others — an "absolute" minimum of light, below which it is impossible to use even the night mode. This point should be clarified according to the official documents of the manufacturer.

Anyway, the lower this indicator, the less light the camera needs to work and the better it handles with shooting at dusk or even at night. Thanks to the use of special technologies, some models are able to work even in complete darkness, with an illumination of 0 lux; this is due to the fact that modern sensors are able to perceive infrared radiation invisible to the eye. However, more often than not, shooting still requires a certain amount of light — at least tenths of a lux. For comparison: an illumination of 0.1 lux approximately corresponds to a lunar night with a “half” phase of the moon, and 1 lux is comparable to a bright full moon in southern latitudes.

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.