Comparison Canon LEGRIA HF G40 vs Canon LEGRIA HF G30

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 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.

— Component. An interface for transmitting a video signal in an analogue format, dividing the “picture” into three components (hence the name) and transmitting each of the components via a separate wire. Due to this, a fairly high image quality and good bandwidth are ensured: the component interface surpasses S-Video in quality and is suitable even for high definition (HD) operation. On the other hand, it does not provide working with audio — so if you want to hear sound, you will have to take care of a separate channel for its transmission. On stationary video equipment, three separate RCA connectors (“tulip”) are usually used for component connection, the same format can be used in professional video cameras, but in amateur models (see “Features”) the component output has a more compact design — for example, in the form of a 3.5 mm mini-jack socket.

— USB. A universal interface used in computer technology to connect various external peripherals. It is extremely widespread, available in the vast majority of modern desktop PCs and laptops. When connected to a computer via USB, the camcorder also functions as a peripheral device. The most popular use of this connection is for copying footage, but it may include other options depending on the model: remote control of the camera, firmware upgrade, USB streaming, webcam operation (see "Features") . In addition, it is this...interface that is used for direct copying to the HDD (ibid.); in this case, the camera plays the role of a control device, and the storage plays the role of a peripheral.

— HDMI. High-speed digital interface for transmitting video and audio signals over a single cable. Has enough bandwidth to work with high-definition video and multi-channel audio. The HDMI output in the camcorder is very convenient for using it as an external player when viewing footage: the vast majority of modern TVs and monitors have at least one input of this standard. It is also widely used in other video equipment.

— S-video. Interface for transmitting video signal in analogue format. Like component connection (see above), this standard does not work with audio and uses separate transmission of signal components — however, in this case there are 2 of these components, not 3. This, on the one hand, somewhat reduces the quality of the “picture”, on the other — allows you to use one cable and one connector instead of three. But one of the significant shortcomings of S-Video is the impossibility of working with HD — the bandwidth is only enough for a standard definition signal.

— IEEE 1394. Also known as FireWire. Although IEEE 1394 is now a very versatile interface used in computer technology, it was originally used specifically in camcorders — primarily to “capture” video from a magnetic tape and convert it to files. This application is relevant even now — almost all cameras with miniDV (see "Media type") have such an output, it is also found among other devices, mostly professional ones (see "Features"). A FireWire connection can provide other options – similar to the USB described above.

— SDI. A digital interface used to transmit video and audio signals, as well as service information. The bandwidth of SDI is somewhat lower than that of HDMI, but for a number of reasons it is much better suited for professional use and is quite widely used in related video equipment, including cameras. But in amateur models (see "Features"), the outputs of this standard are not installed.

— AV-output. Connector for transmitting video and audio in analogue format. This interface is also called "composite", but the classic composite input or output uses several RCA connectors (one for video and one for mono audio, or two for stereo). In camcorders, this interface is usually made in the form of a 3.5 mm jack (mini-jack), and appropriate cables are used to connect to full-size video equipment. The main advantage of the AV-output over other analogue standards (component and S-Video, see above) is the ability to transmit video and audio simultaneously. At the same time, in terms of image quality, it loses to the mentioned options due to the fact that all components of the video signal are transmitted over one cable and the resistance to interference is low.

— Microphone input. Connector for connecting an external microphone to the camcorder. This feature is important in cases where the microphone needs to be placed at some distance from the camera — for example, when shooting TV programs or reports. Professional models (see "Features") may have several of these inputs, and they can also be used for multi-channel audio recording and other specialized applications. Please note that XLR microphone connectors are listed separately in our catalog (see below).

— XLR microphone input. The presence in the design of the camera at least one input for an external microphone using an XLR connector. The role of the external microphone is described in detail above. As for XLR, it is an interface widely used in professional audio and video equipment, including cameras. Its main feature is the possibility of the so-called balanced connection; this connection is highly resistant to interference even with long cable lengths and is well suited for use with high quality microphones. The connector itself is quite large, but given the sizes of professional video cameras, this is not a drawback. It is worth noting that 1 channel of sound is transmitted through one XLR input, so several of them can be provided — usually two, for stereo recording.

— Headphone jack. The presence of a headphone output in the design of the video camera. The main function of this feature is to listen to the sound that accompanies the captured video. Headphones generally provide better quality than the built-in speaker (see "Features") and are even more comfortable in some situations, such as in a noisy environment or when silence is required. Another purpose of the headphones is to control the sound characteristics right during the recording process, but this feature is usually found in professional models (see "Features"). Most often, a standard 3.5 mm mini-jack socket is used as a connector, but there are other options; all of them are included in this section — except for the XLR described below.

— XLR headphone jack. The camcorder has a headphone output using an XLR connector. The features of the connector itself are described in detail above in the paragraph “XLR microphone input”, and the role of the headphones is described in the paragraph “Headphone output”. At the same time, we note that XLR, being a professional interface, is intended not so much for listening to recorded materials, but for other, more serious tasks — in particular, monitoring sound during filming.

The battery life of the camcorder from a fully charged standard battery. Usually, the specifications indicate the battery life in the recording mode, but in perfect conditions — without using additional features such as zoom, backlight, etc., which also “eat up” the charge. And if there is a viewfinder (see "Features"), the shooting time is usually indicated through this device, and not through an external display. Therefore, in fact, the battery life may be less, but in general, this parameter quite clearly describes the capabilities of a particular camera, and different models can be compared by it.

Note that for many cameras, in addition to regular ones, also “reinforced” batteries are produced, which allow increasing battery life by 2-3 times. Therefore, if you are not satisfied with the operating time in the selected model, it makes sense to ask about the availability of such batteries.