Comparison Sony A7r II body vs Sony A7 II body

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.

The total number of individual light sensitive dots (pixels) provided in the camera's sensor. Denoted in megapixels - millions of pixels.

The total number of MPs, as a rule, is greater than the number of megapixels from which the frame is directly built (for more details, see "Effective number of MPs"). This is due to the presence of service areas on the matrix. In general, this parameter is more of a reference than practically significant: a larger total number of MPs with the same size and effective resolution means a slightly smaller size of each pixel, and, accordingly, an increased likelihood of noise (especially at high ISO values).

The number of pixels (megapixels) of the matrix directly involved in the construction of the image, in fact — the number of points from which the captured image is built. Some manufacturers, in addition to this parameter, also indicate the total number of MPs, taking into account the service areas of the matrix. However, it is the effective number of MPs that is considered the main indicator — it is this that directly affects the maximum resolution of the resulting image (see “Maximum image size”).

A megapixel is 1 million pixels. Numerous megapixels ensures high resolution of the captured photos, but is not a guarantee of high-quality images — much also depends on the size of the sensor, its light sensitivity (see the relevant glossary items), as well as hardware and software image processing tools used in the camera. Note that for small matrices, high resolution can sometimes be more of an evil than a blessing — such sensors are very prone to the appearance of noise in the image.

The maximum size of photos taken by the camera in normal (non-panoramic) mode. In fact, this paragraph indicates the highest resolution of photography — in pixels vertically and horizontally, for example, 3000x4000. This indicator directly depends on the resolution of the matrix: the number of dots in the image cannot exceed the effective number of megapixels (see above). For example, for the same 3000x4000, the matrix must have an effective resolution of at least 3000*4000 = 12 million dots, that is, 12 MP.

Theoretically, the larger the size of the photo, the more detailed the image, the more small details can be conveyed on it. At the same time, the overall image quality (including the visibility of fine details) depends not only on resolution, but also on a number of other technical and software factors; see "Effective MP number" for more details.

The sensitivity range of a digital camera matrix. In digital photography, light sensitivity is expressed in the same ISO units as in film photography; however, unlike film, the light sensitivity of the sensor in a digital camera can be changed, which gives you more options for adjusting shooting parameters. High maximum light sensitivity is important if you have to use a lens with a low aperture (see Aperture), as well as when shooting dimly lit scenes and fast-moving objects; in the latter case, high ISO allows you to use low shutter speeds, which minimizes image blur. However, note that with an increase in the value of the applied ISO, the level of noise in the resulting images also increases.

No AA filter in camera design.

The AA filter is responsible for "anti-aliasing" — the elimination of the moiré effect. This effect can occur when shooting objects with a lot of thin horizontal or near-horizontal lines (for example, a brick wall at a great distance, or a suit made of a certain type of fabric). It leads to the appearance of a characteristic pattern in the picture, which, usually, is inappropriate; to eliminate this phenomenon, an AA filter is provided. At the same time, this feature is said to reduce the overall sharpness of the image; therefore, it may not be available in some cameras. These are mainly professional models: the absence of an AA filter gives the photographer additional features, but puts forward increased requirements for shooting skills.

An image stabilization method provided by the camera. Note that systems of the optical type and with a sensor shift are sometimes combined under the term "true" stabilization - due to their effectiveness. See below for more on this.

By itself, stabilization (regardless of the principle of operation) allows you to compensate for the effect of "shake" with an unstable camera position - especially when shooting handheld. This is especially true when shooting with a significant increase or at slow shutter speeds. However, in any case, this function reduces the risk of spoiling the frame, so cameras with stabilization are extremely common. The principles of work can be as follows:

— Electronic. Stabilization, carried out due to a kind of "reserve" - a section along the edges of the sensor, which initially does not participate in the formation of the final image. However, if the camera electronics detect fluctuations, it compensates for them by selecting the necessary image fragments from the reserve. Electronic systems are extremely simple, compact, reliable and at the same time inexpensive. However, for their work it is necessary to allocate a fairly significant part of the sensor - and reducing the usable area of the sensor increases the noise level and degrades the image quality. And in some models, electronic stabilization is turned on only at lower resolutions and is not available at ful...l frame size. Therefore, in its pure form, this option is found mainly in relatively inexpensive cameras with non-replaceable lenses.

- Optical. Stabilization, carried out when light passes through the lens, is due to a system of movable lenses and gyroscopes. As a result, the image hits the sensor already stabilized, and the entire sensor area can be used for it. Therefore, optical systems, despite the complexity and rather high cost, are considered more preferable for high-quality filming than electronic ones. Separately, we note that in SLR and MILC cameras (see "Camera Type") the availability of this function depends on the lens installed; therefore, for such models, optical stabilization is not indicated in our catalog in principle (even if the complete lens is equipped with a stabilizer).

- With sensor shift. Stabilization, carried out by shifting the sensor "following" the shifted image. Like the optical one described above, it is considered a fairly advanced option, although in general it is somewhat less effective. On the other hand, systems with a sensor shift have serious advantages - first of all, the fact that such stabilization will work regardless of the characteristics of the lens. For cameras with fixed lenses, this means that the lens can do without an optical stabilizer and make the optics simpler, cheaper and more reliable. In SLR and MILC cameras, the sensor shift makes it possible to use even “non-stabilized” lenses with convenience, and when installing “stabilized” optics, both systems work together, and their efficiency is very high. In addition, sensor shift is somewhat simpler and cheaper than traditional optical stabilizers.

— Optical and electronic. Stabilization that combines both of the options described above: initially it operates according to the optical principle, and when the capabilities of the lens are not enough, an electronic system is connected. This improves the overall efficiency compared to purely optical or purely electronic stabilizers. On the other hand, the disadvantages of both options in such systems are also combined: the optics are relatively complex and expensive, and not all of the sensor is involved. Therefore, such a combination is rare, mainly in separate advanced digital compacts.

- With sensor shift and electronic. Another type of combined stabilization systems. Like “optical + electronic”, it improves the overall stabilization efficiency, but at the same time it combines the disadvantages of the two methods (they are also similar: the complication and rise in price of the camera, plus a decrease in the useful area of \u200b\u200bthe sensor). Therefore, this option is used extremely rarely - in single models of digital ultrazooms and advanced compacts.

The number of scene programs provided in the camera design.

Scene programs are preset settings for some of the most common shooting scenes - for example, Portrait, Landscape, Sports, Sunset, etc. In addition to these presets, this list may include special effects and creative tools (such as color swap or fisheye), as well as exposure modes (see below). The presence of scene programs is especially useful for beginners and non-professional photographers, as it eliminates the need to tinker with each setting separately - just select the most suitable program, and all the necessary settings will be set automatically. The more scene programs the camera design provides, the wider its automatic adjustment capabilities.