Ultra wide lens
Specs of the
ultra wide-angle lens of the main camera installed in the phone.
These details are relevant only for cameras with several lenses (see "Number of lenses") — and not all, but only those where there is a lens with a small focal length (much less than in the main lens) and, accordingly, wider viewing angles. It is called ultra-wide. In the same paragraph, four main parameters can be indicated: resolution, aperture ratio, focal length and additional sensor data.
Resolution(in megapixels, MP)
The resolution of the sensor used for the ultra-wide lens.
The maximum resolution of the resulting image directly depends on the resolution of the sensor; and the high resolution of the "picture" allows you to capture small details better. On the other hand, an increase in the number of megapixels in itself can lead to a deterioration in the overall image quality — due to the smaller size of each individual pixel, the noise level increases. As a result, the direct resolution of the camera has little effect on the quality of photos and videos — a lot also depends on the size of the sensor, the features of the optics and various design tricks used by the manufacturer. At the same time, we note that the more megapixels a camera has, the more likely it is to implement various additional solutions aimed at improving image quality.
As for the specific resolution of ultra-wide optics, it can co
...rrespond to the number of megapixels in the main lens (see "Main lens") or be lower, sometimes quite noticeable (for example, 8 MP with the main optics at 48 MP). This is due to the fact that an ultra-wide-angle lens often plays a secondary role, for which a small resolution is more than enough.
Aperture
Aperture describes the ability of a lens to transmit light. It is written as a fractional number, for example f/1.9. Moreover, the larger the number in the denominator, the lower the aperture ratio, that is, for example, an f/2.6 lens will transmit less light than f/1.9.
High aperture gives the camera a number of advantages: it allows you to shoot at low shutter speeds, minimizing the likelihood of “shake”, and also makes it easier to shoot in low light and shoot with artistic background blur (bokeh). However, for an ultra-wide lens, such features are not as important as for the main camera — such lenses usually have a specific purpose, and their small aperture is often more desirable, which allows you to increase the depth of field. So in general, this parameter is more of a reference than practically significant when choosing.
Focal length
The focal length is a distance between the sensor and the centre of the lens (focused to infinity), at which the most clear image is obtained on the sensor. However, for smartphones, the specifications indicate not the actual, but the so-called equivalent focal length — a conditional indicator recalculated using special formulas. This indicator can be used to evaluate and compare cameras with different sensor sizes (the actual focal length cannot be used for this, since with a different sensor size the same real focal length will correspond to different viewing angles).
Anyway, the viewing angle and the degree of magnification directly depend on the equivalent focal length: a larger focal length gives a smaller viewing angle and a larger size of individual objects that fall into the frame, and a decrease in this distance, in turn, allows you to cover more space. Ultra-wide optics, by definition, must have very short focal lengths — smaller than the corresponding main optics. However, "ultra-wide" focal lengths typically range from 13 mm to 26 mm; such values are not rare among the main lenses. At the same time, there is nothing illogical here — the point is the ratio of focal lengths in each individual smartphone. For example, a camera with a 25mm primary lens can carry a 16mm or 17mm ultra-wide lens; and models with a primary lens less than 24mm usually do not have additional ultra-wide optics at all, since the existing lens perfectly plays this role just fine. Also note that the difference between these types of optics is not as significant as one might imagine; and in some devices, both focal lengths are generally the same, while the difference in specialization is achieved due to the features of image processing in each lens.
Field of view(in degrees) It is the size of the area covered by the lens, as well as the size of individual objects "seen" by the camera. The larger this angle, the more of the scene gets into the frame, but the smaller the individual objects in the image are. The field of view is directly related to the focal length (see above): increasing this distance narrows the field of view of the lens, and vice versa.
Note that this parameter is generally considered important for professional use of the camera rather than for amateur photography. Therefore, the field of view data is given mainly for smartphones equipped with advanced cameras — including in order to emphasize the high class of cameras in this way. As for specific values, ultra-wide-angle optics, by definition, have very wide angles — from 107° and above; in some models, this figure reaches 125°.
Additional Sensor Data
Additional information regarding the sensor installed in the ultra-wide lens. This item can specify both the size (in inches) and the sensor model, and sometimes both parameters at once. Anyway, such data is provided only if the device is equipped with a high-class sensor. With the model, everything is quite simple: knowing the name of the sensor, you can find detailed data on it. The size is worth considering a little more.
The size of the sensor is traditionally indicated in fractional parts of an inch — accordingly, for example, a 1/3.1" sensor will be larger than 1/4". Larger sensors are considered more advanced, as they provide a better image at the same resolution. This is due to the fact that due to the larger sensor area, each individual pixel is also larger and receives more light, which improves sensitivity and reduces noise. Of course, the actual image quality will also depend on a number of other parameters, but in general, a larger sensor size usually means a more advanced camera. However, in ultra-wide lenses, the sensors are generally noticeably smaller than in the main ones — for example, the mentioned 1/3.1" and 1/4" are quite common options. This is primarily due to the secondary role of such cameras.Additional lens
Specs of the additional lens installed in the device.
An additional lens is the one that is not covered by any of the three categories described above (main, tele-, ultra-wide), but is used directly for taking photos and videos (that is, it is not an auxiliary one — see below). In this case, the specific purpose of such a lens may be different. In some models, modules for a specific purpose are installed — for example, "portrait" optics with a longer focal length than the main module (however, less than that of a telephoto lens). In other devices, you can find additional modules of standard specialization — for example, the second telephoto lens, which differs in specs from the main one; data on such modules is also given here.
The meaning of particular specifications is described in detail above, in the paragraphs regarding the main lens, telephoto lens and ultra-wide optics. Here we note some nuances that directly relate to additional modules or are worth re-mentioning:
- Resolution (in megapixels, MP). In itself, high resolution only increases the detail and does not necessarily improve the quality of the picture. However, numerous MPs is often a sign of an advanced camera, where various additional solutions are used to improve quality.
- Aperture. Written as a fraction, such as f/1.9; the larger the number in the designation, the lower the aperture ratio and the worse the light transmission of the lens. These optics are more expensive, but...offer better image quality and more overall performance.
- Focal length. Specified in millimetres. Directly affects the viewing angle and specialization of the lens: short focal lengths are typical for "wide-angle" and lenses for general use, significant — for "portrait" and telephoto lenses.
- Sensor size. Specified in fractions of an inch, such as 1/2.8". A larger sensor is more expensive and takes up more space, but provides better image quality.
- OIS. An abbreviation for "optical image stabilization". See below for more details on such systems, but here we note that they are typical mainly for advanced cameras: optical stabilization is more complicated and expensive than digital, but more effective.
Auxiliary lens
The presence of an
auxiliary lens in the module of the main (rear) camera of the smartphone. Common to all auxiliary lenses is that they themselves do not shoot, but only supply the main camera with some useful additional data. But the types of this data and, accordingly, the methods of using auxiliary cameras can be different.
So, in some smartphones, an additional lens of a very small resolution is installed, which is used to obtain special information about the depth of field in some shooting modes (primarily in portrait mode). This format of work gives a number of interesting features — in particular, it allows you to change the depth of focus on an already finished image, moving the focus to a particular subject. Another interesting option is the so-called ToF (time of flight) cameras, which work on the principle of rangefinders and are capable of creating 3D models of various objects (including reading facial expressions from the user's face). There are other options, such as a black-and-white secondary camera for greater dynamic range and a fast aperture for better low-light performance.
Thermal imager
The thermal imager allows you to get a thermal map of the area, which is superimposed on the image from the main camera. That is, the thermal imager and the smartphone camera work in conjunction. The scope of the thermal imager is very wide. Thanks to the thermal sensor, it is possible to detect: places of heat leakage from the building; heating wiring; the presence of animals in the area when it is already dark, etc. To use a mobile thermal imager, special software is provided, similar to the smartphone camera programme. Of course, the capabilities of a mobile thermal imager are much inferior to the potential of individual thermal sighting equipment. In particular, a thermal imager on a mobile phone gives a picture with a minimum resolution, within about 80x60 pixels. It can be used in phones for construction workers and in some cases can replace
a professional thermal imager.
