Comparison Canon PowerShot G7X Mark II vs Canon PowerShot G9X

The result shown by the camera in the DxOMark ranking.

DxOMark is one of the most popular and respected resources for expert camera testing. According to the test results, the camera receives a certain number of points; The more points, the higher the final score.

— 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.

Aperture of the lens installed in the camera or supplied with it in the kit (for models with detachable optics).

In a simplified way, this parameter can be described as the ability of the lens to transmit light - in other words, how much the light flux weakens when passing through the optics. It is believed that two main indicators affect the characteristics of light transmission: the size of the relative opening of the lens and its focal length. Aperture is the ratio of the first indicator to the second; in this case, the size of the active hole is taken as one and is generally omitted when recording, as a result, such a recording looks, for example, like this: f / 2.0. Accordingly, the larger the number after the fraction sign, the lower the aperture ratio, the less light the lens transmits.

Zoom lenses (zoom lenses), as a rule, have different aperture values for different focal lengths. For such optics, two values of this parameter are indicated in the characteristics, for the minimum and maximum focal lengths, for example, f / 2.8–4.5. There are also vario lenses that maintain a constant aperture over the entire range of focal lengths, but they are much more expensive than analogs with variable aperture.

The high light transmission of the lens is important if the camera is planned to be used for shooting in low light conditions or for shooting fast moving objects: high-aperture optics allow you to shoot at low sensor sensitivity (which...reduces the likelihood of noise) and at low shutter speeds (at which moving objects are less blurry) . This parameter also determines the depth of field of the imaged space: the higher the aperture ratio, the smaller the depth of field. Therefore, for shooting with artistic background blur (“bokeh”), it is recommended to use fast lenses.

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.

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.

The presence of two control dials in the design of the camera.

This design feature makes it easier to control the camera and change settings on the fly: additional operating parameters are transferred to the second disk, and turning it to the desired position is easier and faster than “digging” in the on-screen menu items. This feature is found mainly in semi-professional and professional cameras, which involve frequent use of manual shooting mode.

The number and / or types of scene programs for shooting videos provided in the design of the camera.

Scene programs are a set of presets designed for different shooting situations - for example, in sunlight, on a cloudy day, in a darkened room, etc. Also, this list may include other specific modes - for example, creative tools. In any case, the presence of scene programs facilitates the choice of video shooting parameters, which is very useful for novice users.

Autofocus operating modes provided in the camera design.

— One picture. The main mode of autofocus operation is found in all modern cameras and is used most often. Designed for shooting motionless objects.

— Follower. This mode is used for shooting moving objects, the distance to which is constantly changing: the camera constantly monitors the position of the object, constantly adjusting the optics so that it is in focus. Usually found in middle and upper class cells.

— AI focus. A peculiar combination of the previous two modes is used when a stationary object can start moving at any moment. If the scene is static, autofocus works in the single frame mode, but if the object on which focus is made starts to move, the device switches to tracking autofocus mode. AI mode allows you to almost instantly set the optimal autofocus settings, which is especially useful for sequential shooting. Initially, it was found in expensive models, however, thanks to the development of technology, today it can even be used in inexpensive compacts (see “Camera type”).

— By the face. Autofocus mode that uses a face recognition system and focuses on them. This feature is especially useful for taking pictures of people at a great distance from the camera, when the face is much smaller than the frame size, such as in group shots.

— With a smile. A further development of the face autofocus mode described above, when, in accordance with the nam...e, the system reacts not just to a face, but to a smile. This mode can be combined with the function of automatic shooting at the moment of a smile.

— Animal in the frame. A mode designed primarily for shooting animals, which can be difficult (and often impossible) to make them sit still in the frame. It is usually a variation of the tracking autofocus described above, but specific features of operation may vary depending on the camera model.

This list is not exhaustive, and other specific autofocus modes may be provided in the design of modern cameras.

The number of focus points (autofocus) provided in the design of the camera.

The focus point is the point (more precisely, a small area) in the frame from which the autofocus system reads data for focusing. The simplest systems work with a single point, but their capabilities are very limited, and this option is practically not found today. Modern digital cameras have at least three focus sensors, and in the most advanced models this figure can reach several dozen.

The more autofocus sensors there are in the camera, the more advanced its autofocus capabilities will be, the more specific techniques it allows you to use. In this case, the selection of specific points used can be carried out both automatically, simultaneously with the choice of the subject program, and manually (however, the second option is more typical for professional cameras). In addition, the abundance of focus points has a positive effect on the quality of the tracking autofocus (see "Autofocus Modes").

In general, more focus sensors are generally considered a sign of a more advanced camera; however, differences in quality become really noticeable only if the difference in the number of points is significant - for example, if we compare models with 9 and 39 points. A lot also depends on the location of the points in the frame - it is believed that sensors distributed over a wide area work better than densely located in the center of the frame, even if their number is the same.