Comparison Sony A6400 kit 16-50 vs Sony A7 III kit 24-70

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 physical size of the photosensitive element of a camera. Measured diagonally, often indicated in fractions of an inch — for example, 1/2.3" or 1/1.8" (accordingly, the second matrix will be larger than the first). Note that in such designations it is not the “ordinary” inch (2.54 cm) that is used, but the so-called "Vidiconovsky", which is less than a third and is about 17 mm. This is partly a tribute to the tradition that comes from television tubes — “vidicons” (the forerunners of modern matrices), partly a marketing ploy that gives buyers the impression that the matrices are larger than they actually are.

Anyway, at equal resolution (see Number of megapixels), a larger sensor size means a larger size of each individual pixel; accordingly, on large sensors, more light enters each pixel, which means that such sensors have a higher photosensitivity (see Light sensitivity) and a lower noise level, especially when shooting in low light conditions.

Most often in modern cameras there are such options:

— 1/2.3" and 1/1.7". Small matrices, typical for models without interchangeable lenses — compacts and digital ultrazooms(see "Camera type").

— 4/3. A kind of "transitional option" between small sensors of compact devices and large, but at the same time expensive "SLR" APS-C. The size of such a matri...x is 18x13.5 mm, which gives a diagonal of 22.5 mm (approximately 4/3 of the "Vidicon" inch described above, hence the name). It is used in SLR and "mirrorless" cameras (see "Camera type"), mainly entry-level, with Four Thirds and Micro Four Thirds mounts, respectively.

— APS-C. The size of matrices of this type can vary from 20.7x13.8 mm to 25.1x16.7 mm, depending on the manufacturer. They are widely used in entry-level and mid-level SLRs, as well as "mirrorless" models.

— APS-H. Somewhat larger than the APS-C described above (the size is 28.1x18.7 mm), otherwise it is almost completely the same.

— Full frame (or APS). The size of such a matrix is equal to the frame size of a classic photographic film — 36x24 mm. It is usually equipped with professional-grade SLR cameras.

— Big frame. This category includes all types of matrices, the size of which exceeds 36x24 mm (full frame). Cameras with similar sensors belong to the so-called medium format class and are, usually, professional models of the premium level. Large matrices allow you to use a resolution of tens of megapixels, while maintaining high clarity and colour quality, however, such devices cost accordingly.

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 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.

The presence in the camera of a special mechanism for cleaning the matrix from dust and other contaminants.

This function is found only in models with interchangeable lenses — "reflex cameras" and MILC (see "Camera type"). When replacing the lens in such cameras, the sensor turns out to be open, and the probability of its contamination is quite high; and extraneous particles on the matrix, at best, lead to the appearance of extraneous artifacts, at worst, to damage to the sensor. To avoid this, cleaning systems are provided. They usually work on the principle of ultrasound: high-frequency vibration "resets" debris from the surface of the sensor.

Note that no cleaning system is perfect — in particular, such systems are “too tough” for condensate, salt deposits and other similar contaminants. So the matrix may still need manual cleaning (ideally, in a service centre). Nevertheless, this function allows you to effectively deal with at least dust, which greatly simplifies the life of the user.

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.