Viewing angles
This parameter determines the size of the area of the scene being shot that falls into the frame. The wider the viewing angles, the larger the area the lens can capture in one shot. They are directly related to the focal length of the lens (see "Focal length"), and also depend on the size of the specific matrix with which the optics are used: for the same lens, the smaller the matrix, the smaller the viewing angles, and vice versa. On our website, in the characteristics of optics, viewing angles are usually indicated when used with the matrix for which the lens was originally designed (for more details, see "Matrix Size").
Min. diaphragm
Aperture is a design of several blades-curtains, which allows, if necessary, to reduce the diameter of the active aperture of the lens, actually reducing its aperture (for more details, see "Aperture"). In addition to reducing the light output (which can be relevant, for example, in bright sunlight), closing the aperture has another effect — it increases the depth of field. In other words, “in focus” is a larger volume of space than with an open aperture.
The values on the aperture scale are usually selected from a standard range. The numbers in it actually indicate what aperture the lens will have when the aperture is closed to a given value: for example, an aperture value of 5.6 will correspond to f / 5.6 aperture. The larger the number indicating the minimum aperture value, the more options the photographer has and, accordingly, the possibilities for setting the shooting mode (ceteris paribus).
Maximum zoom
The degree of magnification of the object being shot when using a
lens for macro shooting (that is, shooting small objects at the maximum possible approximation, when the distance to the subject is measured in millimetres). The degree of magnification in this case means the ratio of the size of the image of the object obtained on the matrix of the camera to the actual size of the object being shot. For example, with an object size of 15 mm and a magnification factor of 0.3, the image of this object on the matrix will have a size of 15x0.3=4.5 mm. With the same matrix size, the larger the magnification factor, the larger the image size of the object on the matrix, the more pixels fall on this object, respectively, the clearer the resulting image, the more details it can convey and the better the lens is suitable for macro photography. It is believed that in order to obtain macro shots of relatively acceptable quality, the magnification factor should be at least 0.25 – 0.3.
Design (elements/groups)
The number of elements (in fact, the number of lenses) included in the design of the lens, as well as the number of groups in which these elements are combined. Usually, the more elements provided in the design, the better the lens handles with distortions (aberrations) when light passes through it. On the other hand, numerous lenses increases the dimensions and weight of the optics, reduces light transmission (for more details, see "Aperture") and also puts forward increased requirements for the quality of processing, which affects the cost of the lens.
