Comparison Sony HDR-CX405 vs Sony HDR-CX280E

The total number of individual photosensitive points (pixels) provided in the design of the sensor (1 megapixel corresponds to a million pixels). This parameter takes into account both those points on which the light falls, and service points that are not directly involved in the construction of the image. Therefore, in modern video cameras, it is more of a reference than practically significant; the actual image quality depends primarily on the number of effective megapixels (see below).

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 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.

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.

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.

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.

Presets and white balance adjustment modes provided by the camera.

White balance is a characteristic that describes the qualities of the lighting of the scene and the distortion that this lighting introduces into the colours perceived by the camera. Its used because modern digital sensors are unable to independently adjust to different light sources, as the human eye does. In fact, this means that the same object shot under lighting with different colour temperatures (for example, under a “warm” incandescent lamp and a “cold” fluorescent lamp) will look different without adjustment. To avoid this, the white balance setting is applied.

The main options for such a setting used in modern cameras are as follows:

— Auto. In accordance with the name, in this mode, the camera electronics independently evaluates the specifics of the illumination of the scene being shot and makes appropriate corrections to the colour reproduction. This adjustment is the most convenient for the operator, because. does not require any additional actions from him — everything is done by automation. At the same time, no such adjustment system is perfect, and does not always provide 100% white balance for the current situation. Therefore, even in the simplest models like pocket ones (see "Features"), this option is rarely the only one, not to mention professional equipment.

— Presets. The ability to select white balance from several options that correspond to...standard shooting conditions — for example, “sunny day”, “cloudy”, “fluorescent lamp”, “incandescent lamp”, etc. Such a system is quite simple even for inexperienced users and at the same time quite reliable and versatile, although its specific capabilities directly depend on the number of presets.

— Manual. Manual white balance setting assumes that the operator himself “tells” the camera which object to consider pure white — based on this, the electronics calculate the lighting characteristics (unlike automatic mode, when the reference object is also determined without user involvement). The easiest way to do this is to use a regular sheet of paper, but the procedure also works with neutral grey objects. Manual mode allows you to very accurately set the white balance for a particular scene, but it requires some time and appropriate skills — and therefore is used mainly in professional camcorders.

— Temperature control. This function allows you to set a specific value for the colour temperature of the light source (in kelvins) — it is this temperature that will correspond to the white balance when shooting. This setup format is faster and more convenient than manual setup, but is not widely used. This is due to the fact that it is well suited only for studio conditions, where the characteristics of each light source are precisely known — in other cases, manual adjustment is usually more reliable.

The number of auto exposure modes (scene programs) provided in the camera design.

Exposure is a certain combination of the main shooting parameters — shutter speed, aperture and sensor sensitivity. Different situations may require different combinations to obtain the best image quality. For example, for shooting dynamic scenes, relatively fast shutter speeds are required to avoid blurring each frame — and for normal illumination of each frame, you need to open the aperture or increase the sensitivity. In portrait shooting, the conditions are dictated by the aperture, etc. Auto exposure makes it much easier to set all the parameters mentioned — instead of selecting a combination manually, the operator just needs to turn on a certain scene programme on the camera.

The more auto exposure modes, the more extensive the camera's ability to adjust to a specific situation, the easier it is to work with it under a wide variety of shooting conditions. At the same time, it is worth noting that when calculating these modes, our catalog takes into account not only automated presets (“portrait”, “beach”, “sunset”, etc.), but also “full automatic”, when the camera itself determines the specifics of the scene, and a fully manual setting mode.

A list of scene programs (also known as auto exposure modes) provided in the camera design. See "Auto exposure" for details on the meaning of these programs.