How to choose a lens for a camera?

The first thing you should pay attention to when choosing and buying an object is the type of attachment that your camera uses. In the technical literature, it is referred to as a "bayonet" or "system mount". It is important that the camera mount corresponds to what is used in the selected object. By not following this simple rule, you are almost guaranteed to damage the camera matrix.

Each manufacturer has its own fastening system and first of all popularizes it, limiting the possibility of using competitors' objects. So, Nikon's object, usually, will not be able to be used with Sony cameras. Even more: there may be several subsystems within a system of one manufacturer. For example, Canon uses three different bayonets at once — EF, EF-S and EF-M. Sony has A and E. Therefore, before buying an object, it is important to clarify which bayonet your camera uses.

However, some systems still have mutual support. So, for example, all Canon cameras with an EF-S mount are compatible with EF objects. But at the same time, cameras with EF do not support EF-S objects. Another example: the Micro 4/3 system is compatible with all manufacturers that use the Micro 4/3 bayonet (in this case, we are talking about Olympus, Panasonic and the Kodak Pixpro S-1 line of cameras).

The second thing you should pay attention to when choosing an object is the physical size of the matrix for which the object is designed. Each digital camera has a matrix of a certain size. Mirrorless and mirrorless models are most often equipped with APS-C format matrices. Mirrorless mirrors sometimes also use Micro 4/3 or 1” matrices, and professional—level mirrors use full frame or big frame.

It is easier and cheaper to make an object for cameras with APS-C matrices than for a large full frame or big frame format. But unfortunately, APS-C objects are unsuitable for full-fledged use in conjunction with full-format cameras. The reason is that they do not have sufficient resolution to use the full size of the matrix. Because of this, the edges of the frame are darkened. Among photographers, this effect is known as "vignetting". As a result, at the output we get a picture that is unsuitable for use in most genres of photography.

On the other hand, objects designed for large format (full frame and big frame) are completely suitable for smaller matrices. But even in this case, there are several nuances that are worth knowing about. One of them is the so—called crop.

The crop is a conditional coefficient reflecting how much the matrix used is smaller compared to the full frame matrix. The reference size of the matrix is 36x24 mm (aka full frame). For example, take the camera Nikon D7200 body , equipped with an APS-C matrix (its physical size is 25.1x16.7 mm). In this case, the crop indicator is 1.5, since the diagonal of the frame of the matrix is 1.5 times smaller than the reference one.

Let's say you have a full frame object with a focal length of 50 mm. If you want to install it on a Nikon D7200 camera (and, recall, it has an APS-C matrix), then the output frame will be cropped as if you are using an object with a focal length of 75 mm instead of 50 mm, which is actually there. This is not an optical effect, but a real image that falls on the camera matrix. The fact is that the object transmits the image "hoping" that it will fall on a 36x24 mm matrix. But since the Nikon D7200 matrix has a physical size of 25.1x16.7 mm, the frame is cropped. To calculate the actual focal length, it is necessary to multiply the real focal length by the crop of the matrix (in the above example, we multiplied 50mm by 1.5, which gave us 75 mm).

Separation of objects by types

Despite the similar appearance, objects are divided into several types, each of which is created for specific tasks.

Wide-angle objects

Objects with a very wide capture of the scene fall under the category of wide-angle. First of all, this includes models with a focal length of 8-25 mm. Their scope of application is quite wide, but most often it is landscape and architectural photography, filming of a group of people and other genres where maximum space capture is required for photography.

It is worth noting that this category also includes the so-called "Fisheye" or "Fisheye" objects (in English "Fisheye"). Photos taken with their help can have a very large angle of field of view (up to 180 °). Fisheye objects have uncorrected distortion, which makes the image in the photo appear convex or even rounded. They are not very popular due to their narrow specialization, you are unlikely to see them in an architectural or classical portrait shoot. Such an object is often used for shooting panoramas (including 3D), street sports, or when shooting in a narrow space.

Universal objects

The word "universal" in the name of this category speaks for itself — such objects have the widest range of focal length and range of application. The standard universal object is a model with focal lengths of 18-55 mm. Using 18 mm, you can try yourself in landscape, architectural or indoor shooting. And 55 mm will help to make a high-quality portrait with a beautiful bokeh, without distorting the shape of the face. Most often, such objects are bundled with kit cameras.

Universal super-zooms with a focal length of 50-250 mm are also available on the market. They can be used both for shooting in a spacious room, and for hunting animals.

Fix

Fixed objects are called objects with an unchangeable focal length. In fact, this means that it will not be possible to zoom in or zoom out (zoom out) the image. Such a solution has several advantages that are not obvious at first glance. First, the design of the object is almost completely devoid of moving elements, which means it does not let air in and, in fact, does not tighten dust. Secondly, the quality of the photos of the fixes is often higher. Third, they perfectly "blur" the background (this effect is called bokeh), although this item applies mainly to long—focus models.

Teleobjective

A telephoto lens is a model whose focal lengths allow you to shoot objects at a distance of 50 metres without loss of quality. Usually the focal length range is in the range of 70-300 mm. It is worth noting that the longer the focal length, the more noticeable the camera shake. That is, the telephoto lens should only be used in combination with a tripod, otherwise the photos will be blurred.

Telephoto lenses with variable focal length rarely have a constant aperture, and models with variable aperture are often quite "dark" (f/3.5 — f/5.6). So, an object of 70-300 mm f/3.5-6.3 at the long end (300 mm) will shoot with a minimum aperture of f/6.3. This means that it will be problematic to take a sharp photo in cloudy weather or twilight. The way out may be the purchase of a high-power telephoto lens with a fixed focal length.

Teleobjectives are indispensable when shooting sports competitions or hunting for animals and birds, they are often used in portrait shooting.

Macroobjective

Macro-objects are used in situations when you need to remove an object from as close a distance as possible and at a large approximation. Such an object has a special design with an offset front lens. There are also models on the market with a special retractable front lens, which photographers jokingly call a "trunk". Such from ordinary objects can be transformed into macro.

It is known that the best solution for macro photography will be a model with a fixed focal length. In this case, the photos will be sharper.

Definitely, macro shooting can be carried out without a specialized object, but this will require additional accessories. First of all — the macro lens, which is wound on the external thread of the object. The magnification effect will not be as large as when shooting with a full-fledged object, but this is quite enough for amateur shooting.

So what to choose?

Before deciding on the type of object, it is worth understanding the goals that you are pursuing.

A good portrait can be done even on a wide—angle object, but in this case you will not get a beautifully blurred background — for this you need a high-power fix with a focal length of 35-200 mm. But if you like landscapes, then you can't do without a wide-angle object.

A good station wagon will always serve as the optimal solution. For the first time, an inexpensive, but preferably high-power zoom is quite enough for a beginner. As an example — 24-70 mm f/2.8 or 17-50 mm f/2.8. As a good portrait painter, you can recommend 50 mm f/1.8 or 35 mm f/1.8. The first is preferable for close portraits, the second will allow you to make full-length portraits due to a smaller focal length.

As for the tele—objects, everything is a little more complicated here, since the choice comes down to either quality or versatility. The best choice for a beginner will be an inexpensive object with focal 55-250mm f/4.0-5.6 or 70-300 mm f/4.0-5.6. You can also look in the direction of fixes: the 200 mm f/4.0 model is not as expensive as the high-speed version of 200 m f/2.8, but for a beginner it is the very thing.

Many photographers buy several objects for different tasks. But not everyone can afford such a solution. When planning the purchase of an object, you should weigh all the pros and cons, and focus on the model that will cover your needs as much as possible.