Comparison Panasonic HC-V770 vs Panasonic HC-W850

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 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 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.

Camera has a pre-recording (Pre-Rec) feature.

This feature makes life significantly easier for the operator in conditions where speed of reaction is important — it reduces the risk of missing the moment by being late with the start of the recording. In fact, Pre-Rec allows you to start filming a few seconds (usually 2-3) before the record button is pressed. This is due to the fact that with the pre-recording mode enabled, the camera constantly captures the last few seconds "seen" by the lens in the buffer, and when recording starts, the video from the buffer is attached to the beginning of the recorded file — this creates the effect of a "time machine".

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.

This function, in accordance with the name, implies the presence of a second camera in the design, the image from which can be recorded simultaneously with the “picture” from the main optics. Such a camera is usually located on a folding screen and is made rotatable, which gives expanded possibilities for its use: for example, the operator can simultaneously film both what is happening and himself; or you can use an additional camera for a wide-angle image, and work with the main optics at high magnifications. Recording in Twin Camera mode is done on a picture-in-picture basis; at the same time, some cameras allow you to simultaneously record an image from the main optics in the usual mode, without an additional window with a picture from the second camera.

The largest photo size that can be taken with the camera. It is customary to designate it in points (pixels), with two numbers corresponding to the horizontal and vertical dimensions — for example, 2048x1536. This parameter directly determines the effective resolution of the sensor when photographing; see "Number of Megapixels" above for details.

Possibility of taking photos during video recording. Usually it is implemented by a separate button, when pressed, the camera captures the visible image as a photo without interrupting video recording.

Of course, modern technologies allow you to save individual frames from an already finished video, but simultaneous photography compares favorably in two ways. Firstly, the resolution of the “picture” in photo mode is often higher than in video recording, and secondly, the procedure of processing a photo differs from the method for processing video frames and allows you to get a better image. So if you need the ability to highlight individual moments in the filmed events, it makes sense to choose a model with this function.