A long focal length lens is a great tool that allows you to get great shots where other lenses are simply powerless. What are its features, advantages and disadvantages? Let's figure it out.
What is this?
A long-focus lens is a device for a camera whose focal length is much larger than the diagonal of the frame. In this case, the angle of view can be from 10° to 39°. The purpose of lenses with such a focal length is to shoot distant objects, because they are able to significantly bring the subject closer and noticeably enlarge the image. They are indispensable if the photographer does not have the opportunity to get close to the subject, but you need to take a photo on a large scale, focus on a small nuance or close-up.
Magnification of the subject will be the more noticeable, the greater the difference between the focal length parameters of the standard and telephoto lenses, and the perspective of the photo will seem more compressed. That is, the distance to distant objects will seem much less.
What are they used for?
Shooting with a telephoto lens is indispensable for hunting for large and small animals. Another area of application for such a device is portrait photography, but it has its own characteristics. So that the proportions of the face are not distorted in the photo, the photographer needs to shoot from a sufficiently large distance (1.5-2 m). Wide-angle and standard lenses produce small images when shooting from this distance.
First Feature
What are the features of long-focus optics?
First, she enlarges the image. For example, an optic with a focal length of 200 millimeters will be almost four times the focal length of a standard lens (50 mm). Accordingly, the image scale will be four times larger. From this it follows that you can find out the magnification by dividing the focal length by 50. For example, the Soviet long-focus lens MTO-1000A has a focal length of almost 1100 mm, respectively, the magnification is 22.
The ability to get close to the subject is one of the most valuable features of such lenses for photographers, because this is the only way to make beautiful shots of wildlife or any other objects that for some reason cannot be approached.
However, this implies one of the main drawbacks of such optics - size. "Powerful" lenses with high magnification are heavy and bulky, they are almost impossible to use without a good support. She most oftenserves as a tripod.
Another negative feature that should be taken into account is that long-focus optics make visible all the shortcomings caused by the quality of the lens itself and camera vibrations. It is almost impossible to avoid with a large weight of the device. Because of this, many telephoto lenses cannot match the image sharpness of conventional lenses, but are much more expensive than the latter.
Second Feature
Another important feature of long-focus optics, for which photographers love it so much, is the ability to highlight the subject against the background, that is, a beautiful blur. This is very useful if, for example, the animal is standing against the background of vegetation. What causes a strong background blur? The fact is that a telephoto lens has a small angle of view (for example, for a device with a focal length of 400 mm, this is only 5 °), and the depth of field is less than that of standard samples. Thus, if the aperture is fully open, then the depth of field is a narrow strip, so everything but the subject itself is in focus.
Third feature
There is another feature that is also associated with a shallow depth of field. It is of particular importance when photographing fauna. Objects, both behind and in front, will be out of focus and blurry. This means that various fine vegetation, which would be clearly visible in a photograph with a standard lens, will be practically invisible in a photograph withtelephoto optics.
Aberrations
Aberrations are photo deviations from the norm. In the case of long-focus lenses, we are talking about a specific type of aberration - distortion, that is, the curvature of geometry. This means that the scale of the photo will change from the center to the edges. Straight lines can become bulging or tend to the edges of the photo, in which case this is the so-called barrel distortion. If the lines become concave and tend to the center, then this is pincushion distortion.
In some cases, chromatic aberration may also occur, which appears as a color outline effect on the object. This can be eliminated after shooting, using graphic editors. The process will be easier if the photographer shoots in RAW format.
Shooting genres
Let's take a closer look at the use of telephoto lenses.
- Sporting events. Photographers in such cases, as a rule, are hindered by fences, and the distance to the subject is quite large. The "telephoto" in this case is simply indispensable, but it is worth remembering that the image is quite easy to "blur", so you need to set the shutter speed to 1/1000 second and use a monopod or tripod.
- Architecture. It is not a problem to examine and capture all the details of this or that architectural building if there is long-focus optics. If with a standard lens from a long distance you can shootonly a general plan, then the "telephoto" will highlight the detail of interest.
- Landscapes. Standard lenses can be inconvenient in landscape photography because they give too wide a shot. A long-focus lens will "take" a mountain peak, a seething waterfall and any other objects that are far enough away.
For Nikon
An example of a popular Nikon telephoto lens model is the Nikon 70-200mm f/4G ED VR AF-S. Photographers call it one of the best lenses in many respects, which, however, do not include the price. At the moment, its minimum threshold is 90 thousand rubles.
This is an excellent telephoto optic with a fixed aperture of 4. Its huge advantage is the sharpness of the image. That is, the shots taken by him are not inferior in sharpness to standard lenses with similar parameters. Compared to its “brothers”, it has a small weight, and few representatives of this type of optics can boast of this. There is an excellent image stabilizer and focusing is quiet.
More budget option - Nikon 70-200mm f/2.8G ED-IF AF-S VR.
For Canon
An example of Canon's telephoto lens is primarily the Canon EF 70-200mm f/2.8L IS II USM. This telephoto lens is very heavy, weighing 1.5 kg, which greatly affects the physical condition of the photographer during long shooting. It will not fit in every bag, so you will have to orpick it up on purpose, or wear the camera in your hands or around your neck.
The lower price threshold is currently 125 thousand rubles.
This high-quality optics has two stabilizer modes, almost silent and very fast autofocus. Its protection is quite high, so the photographer has the ability to take photos in bad weather conditions such as snow and rain. There are chromatic aberrations in the photo, but they are at a low level, but vignetting will appear at an open aperture, which can ruin the frame a little. This Canon telephoto lens comes with a tripod leg.
