Comparison Tamron 28-75mm f/2.8 VXD Di III G2 vs Tamron 70-180mm f/2.8 SP VXD Di III

General lens type. Note that this parameter is largely determined by the equivalent (not actual) focal length, but in the characteristics of optics, the actual value is most often indicated; see "Focal length" for more on this.

The type is not indicated for any optics, but only for models that have a pronounced specialization and clearly fit into a certain category. In addition to them, there are so-called universal lenses — see below about them. And specialized models can be of the following types:

— Fix. This category on our website includes almost all lenses that do not provide the ability to change the focal length. These can be wide-angle models, and optics with a long focal length, providing a high degree of magnification, and models with average values; the only exception is the ultra-wide-angle fisheye, which is a separate type (see below). Due to the simpler design, fixes are usually cheaper and more reliable than similar zoom models. Their main disadvantage is the actual constant focal length. Because of this, when working with fixes, you have to have your own lens for each type of shooting, and zooming in / out of the image is carried out solely by moving the camera closer / farther relative to the object being filmed (in professional jargon — “zoom with your feet”).

— Wide angle. Zoom lenses, the minimum value of which is up to 18 m...m inclusive, the maximum is up to 40 mm inclusive (both are in 35 mm equivalent). This provides a wide viewing angle with virtually no visible distortion (unlike ultra-wide-angle models, see below). "Wide angles" are often used for shooting landscapes, large objects, etc.; also, such a lens can be useful in tight conditions, where you need to capture the widest possible scene (for example, a large group of people), and the situation does not allow you to move far away.

— Ultra wide angle. Also, this type of lens is called fisheye, or "fisheye". Their equivalent focal length is up to 17 mm inclusive, and viewing angles can reach 180° and even more, which allows capturing a very large area of the surrounding space in one picture (for example, the sky around the entire circumference of the horizon). Such lenses have noticeable distortion in the resulting image: the centre of the frame looks closer than the edges, and straight lines that do not pass through the centre of the frame become crooked. Because of this, fisheye optics got their name: the view through it is similar to how a fish sees the ground from under the water. Most often, fisheyes have a fixed focal length, but there are also zoom lenses. Such lenses are used, in particular, to create panoramas, shooting in confined spaces, as well as to provide artistic effects.

— Tele. Lenses with a long focal length and, accordingly, a high degree of magnification, designed primarily for shooting at long distances. If we talk about specific numbers, then in our catalog telephoto lenses include models with a variable focal length, in which the lower limit of the focal length is at least 50 mm, and the upper limit is at least 200 mm. Such optics can be convenient, in particular, when shooting nature, sports competitions and mass events.

In addition to those described above, many lenses are produced that meet the criteria for several types at once or do not fit into any of them. Examples include, in particular, an intermediate option between wide-angle and telephoto lenses with a focal length of 24 to 55 mm, or a model with an extensive adjustment range like 28 – 200 mm, covering both of these types. Such lenses without specialization are called universal. In general, their scope is quite wide, and most of the optics supplied in the kit (kit) with SLR cameras belong to the mentioned “intermediate option”. However in terms of image quality, universal models are often inferior to specialized optics with a similar price; on the other hand, a set of several specialized lenses often costs more than a high-end "station wagon" with the same capabilities.

The general purpose is rather conditional, and in fact the use of optics is not limited to the claimed direction — it all depends on the skills and imagination of the photographer. However, information about the specialization can greatly facilitate the choice. Considering such original options as a cinema lens and a multifunctional.

— Architectural. Lenses designed primarily for shooting buildings. Most of these models are equipped with the Tilt-Shift system (see below). In this case, this function is intended to correct the perspective when shooting tall buildings. In a photograph taken with a normal lens, straight lines can turn out to be curved, which is unacceptable in cases where an accurate representation of the building in the picture is required. Using the Tilt-Shift system allows you to avoid this phenomenon and get a reliable image that does not require additional correction in a photo editor.

— Landscape. In this case, landscape lenses include short-focus (wide-angle) lenses, which, according to test results, provide good image sharpness. In other words, not all “wide-angles” are classified as landscapes, but only those that are actually capable of providing a clear, sharp image.

— Portrait. The hallmarks of a classic portrait lens are: first, the fixed focal le...ngth, which is usually over 50mm (35mm equiv.); secondly, high aperture (most often not lower than f / 2.8, although occasionally there are exceptions). This combination of characteristics allows you to shoot portraits with beautiful background blur, placing the camera at a fairly significant distance; the latter can be useful in studios where additional lighting equipment is used — it is advisable to install the camera behind lighting fixtures so that it does not give a shadow. Speaking of a fixed focal length, it is worth recalling that "fixes" are simpler, lighter and cheaper than zoom lenses, and the ability to adjust the magnification when shooting portraits is rarely required — most often you can completely get by with "zoom with your feet".

— Multifunctional. This direction includes lenses of a universal type (see above), offering the buyer a good value for money; in other words — multi-purpose models with good performance and at the same time relatively inexpensive (namely, "comparatively", the actual price can be quite high). When choosing models in this category, the quality of filming was evaluated according to the results of real tests.

— Film lens. The main feature of cinema lenses is the ability to fine-tune the aperture. The aperture can be closed / opened by 0.1 or even 0.01 mm, while in photo lenses the aperture setting step cannot be less than 1 mm. Additionally, in cinema lenses, aperture is expressed by a T-number, and in photographic lenses, an F-number is used. The operator can shoot multiple cinema lenses with the same aperture, without the need to change the lighting. And when using photo lenses with the same aperture, you often have to adjust the lighting for each optic separately. Cinema lenses are meant to be shot from a tripod, which is reflected in their design features and design — such models are usually larger and heavier than their counterparts for photography.

Minimum focus distance (m) - the smallest distance from which you can focus on an object and take a photo. Usually it ranges from 20 cm for wide-angle lenses to several metres for telephoto. In the macro mode of the camera or with the help of macro lenses, this distance can be less than 1 centimeter.

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.

The size of the matrix for which the lens was originally designed.

The formats (and sizes) of modern matrices can be indicated diagonally in inches (1/1.8", 1/2.3" — in this case, the conditional "Visicon" inch is taken, which is about 17 mm), according to the actual dimensions (13.2x8.8 mm) or by symbol (APS-C, full frame). In general, the larger the sensor, the more advanced and expensive it is.

Among modern lenses, solutions for such matrix formats are most popular, in ascending order of size: 4/3(17.3x13 mm, used in cameras of the Four Thirds and Micro Four Thirds standards), APS-C(23x15 mm with slight variations, SLR and MILC cameras of the middle class), full frame(36x24 mm, the size of a standard film frame — advanced DSLRs), big frame(anything larger than full frame — high-end professional cameras). Optics for other formats is somewhat less common.

Note that it is technically allowed to use with “non-native” sensors, however, in such cases, the performance characteristics of the optics will differ from those claimed. So, when installed on a smaller matrix (for example, a full frame lens on an APS-C camera), only a part of the image created by the lens will fall on such a sensor. As a result, the space that gets into the frame will be narrower, and the details in the frame will be larger, as if the focal...length of the lens has increased (although it has remained unchanged, only the matrix has changed). And when installed on a larger sensor, the covered space will increase, the detail will decrease; in some cases, the size of the “picture” provided by the lens may simply not be enough for the entire area of the matrix, and the pictures will be obtained with black space around the edges.

A type of drive that ensures the movement of lens structural elements during automatic focus. Currently, the following types can be used:

— Ultrasonic motor. The most advanced type of drive to date. Ultrasonic motors are much faster than conventional motors, provide higher accuracy, consume less power and are virtually silent. However, their cost is quite high.

— Stepper motor. Drive control focal length and zoom (zoom). This type of motor is used for the most part only in full-size digital cameras. Among the advantages of a stepper motor, one can note: high reliability and accuracy of operation; in addition, it does not require power supply to maintain focus and zoom. Of course, stepper motors are not without drawbacks. Among the minuses can be identified: slow speed and increased noise. Additionally, a stepper motor is characterized by large dimensions and a rather large weight, which physically does not allow this type of drive to be integrated into the optics of mobile phones and ultra-compact cameras.

— Motor. In this case, an electric motor of a traditional design is meant. Such drives are simple and, as a result, inexpensive. Their disadvantages are the relatively low speed of operation, as well as the noise produced during this; the latter can sometimes be critical — for example, when shooting wildlife. Recently, designers have been us...ing various tricks to neutralize these shortcomings, but in general, the characteristics of conventional motors still remain relatively modest.

— Is absent. The complete absence of an autofocus motor in the lens. Focus such optics can be carried out either by the “screwdriver” system, or strictly manually (for more details on both options, see below).

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.

The number of blades provided in the design of the diaphragm (for details, see "Minimum aperture"). In fact, this parameter is important when shooting scenes with pronounced bokeh (blurred background) and a small depth of field: the more petals the aperture has, the smoother the glare from out-of-focus objects will turn out, while with a small number of petals they can look like polygons. The number of aperture blades has almost no effect on other shooting parameters. Modern lenses have an average of 7-9 petals; the smoothing provided by them in most cases is considered quite sufficient.

Lenses with protection against ingress of dust and moisture. "Protected" optics are useful primarily for those who have to shoot a lot outdoors: they are much more resistant to bad weather than ordinary ones, many of these lenses work quietly in the rain, sea spray, etc. However, the specific degree of protection for different models can significantly differ, this point should be specified separately in the official documentation of the manufacturer. Also note that if you intend to constantly shoot in difficult external conditions, not only the lens, but also the camera itself must have dust and water protection.