Comparison Sony A7r IV body vs Sony A7r III 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.

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.

The size of the camera's native display in pixels. The higher the resolution of the display, the more smooth and detailed the image it reproduces, the less noticeable the graininess and individual pixels, and the more the display as a whole is pleasing to the eye. On the other hand, the high-resolution display affects the cost of the camera itself (albeit quite slightly).

Unlike the rest of modern electronics, it is customary for cameras to indicate this parameter not as the horizontal and vertical size, but as the total number of pixels on the screen. To date, screens of 230K pixels correspond to the entry level, 460K pixels to the average, more than 900K pixels to the advanced.

- GPS module. The camera has a built-in GPS satellite navigation module. In digital cameras, the GPS module is used primarily for setting the so-called. geo-tagging to photos: information about specific geographical coordinates of the shooting location is recorded in the service information about each image. However, the matter is not limited to this, and models with this function can have many additional features - from classic navigation to special programs like a database of points of interest with hints based on the current location.

- WiFi. A wireless standard originally developed for computer networking, but more recently allowing for direct connection between devices. The ways in which Wi-Fi is used in cameras can vary. Thus, the most popular option is to connect to a smartphone, tablet or other similar device for remote control (see below) and / or transfer footage to an external device. Some cameras have built-in software that allows you to directly connect to the Internet through wireless access points and upload photos and videos to popular network services. And in models running Android (see above), specific features depend only on the installed software and may include full access to social networks through client programs (see below) and even web surfing through a browser.

— Bluetooth. A wireless interface used to communicate with various electronic devices. In cameras, Blu...etooth is most often used to connect to a computer or laptop and transfer footage; In addition, it allows you to use the direct printing function on printers equipped with Bluetooth. The range of Bluetooth communication is up to 10 m, and the devices do not necessarily have to be in direct line of sight to each other.

- NFC chip. NFC (Near-Field Communication) is a wireless communication technology designed to connect various portable devices with each other at a distance of up to several centimeters. In cameras it plays an auxiliary role, designed to facilitate connection with other devices (smartphones, tablets, etc.) using a longer-range standard (Wi-Fi or Bluetooth). Instead of delving into the settings - looking for devices, connecting them manually - just bring the NFC camera to a gadget equipped with the same chip and confirm the connection request.

— Control from a smartphone. The ability to remotely control the camera using a smartphone, tablet or other similar gadget. The connection between the camera and the control device is usually carried out via Wi-Fi (see above), while a special application is used for control, and the gadget’s screen plays the role of a viewfinder. The specific capabilities of such control can be different - releasing the shutter on command, selecting exposure parameters and other shooting settings, focusing by touch, etc. Often, it is also possible to “drain” the footage onto the control device and, through it, to the Internet. Note that for cameras used with mobile phones (see “Camera Type”), this function is not indicated: such a camera is usually mounted directly on the device, and there is no talk of remote control.