العدسات واسعة الزاوية Wide Angle .. كتاب فن التصوير الفوتوغرافي

Wide angle lenses

Wide-angle lenses do not have restrictions like those found in telephoto lenses. In contrast to telephoto lenses, we find that wide-angle lenses provide a greater depth of field than that provided by the standard 50 mm lens. But for the lenses

Wide-angle has its own limitations, such as distortion of dimensions, for example - subjects close to the lens are magnified by more than those far from the lens.

However, we note that the distortion of dimensions can be used creatively when we intend to distort the sizes of certain subjects, such as people's faces, for example, to obtain unusual results. But this feature may turn into an obstacle when we do not get rid of it in a snapshot

Dimensional distortion becomes clearer as the focal length of the lens becomes shorter, so it is not. It is clear in 35 mm lenses, but it becomes clearer in lenses such as 28 mm and 18 mm. However, we can mitigate this distortion when it is not desirable by not placing any subjects in the foreground of the image.

Another peculiarity of wide lenses is barrel distortion, a distortion that appears in straight, horizontal and vertical lines. This feature appears most when photographing windows and doors, so we notice the cambering of the edges and their taking a cylindrical shape. This phenomenon also appears on the edges of the lens more than its center. We can avoid this dilemma in an unusual way: buy the most expensive lenses! The glass elements are usually in the cheapest lenses, and therefore the phenomenon of cylindrical aberration is observed in the lenses with the purest elements, or it appears, but slightly.

There is a distinct lens among the various wide-angle lenses, which is the fish-eye lens. It was called as such because it simply resembles a fish-eye, as its viewing angle is 180%, which is the same angle of view in a fish-eye. And the extreme distortion that this lens makes for dimensions made many professional photographers accept to use it to obtain interesting and strange results. It is worth noting that this lens produces circular images due to its extreme distortion of dimensions

last word :

90 Lenses are designed to be attached directly to your camera after removing the standard lens for cameras that do not have removable lenses on the body. This last type of lens is called additional lenses, and they are useful because they increase the capabilities of fixed lenses on cameras, but this increase is limited to a certain range that does not exceed it. For example, we can connect a 90 mm or 35 mm lens to a fixed lens of 50 050 mm, but if you want longer lengths than that, you must use a single lens that is mounted on the front of the used lens and bears the complications associated with its use.

These restrictions do not exist in detachable lenses, because there are multiple lengths, starting from 1000 mm and ending with 18 mm, which can be installed directly on the camera body. Additional lenses are also impractical because the connections between the lenses reduce the quality of the image as a whole. The quality of an image taken with a removable lens cannot be matched with the quality of an image taken with an additional lens.

Close-up photography:

There are three types of adapters that you can install on your camera to get close to the subject for a distance of up to a few centimeters. These types are close-up lenses, couplings and bellows

. bellows

Close-up lenses: These lenses are designed to mount directly on the front of your standard lens. Its visual power is measured in dioptre. There are three optical powers for these lenses, one diopter, which is the weakest, and 3 diopters, which is the strongest. These lenses are known to the sellers as close-up lenses 1, 2 and 3 according to their optical power.

These lenses are suitable for all types of fixed and removable cameras. However, it has an important advantage, which is that it reduces the depth of field to a large extent, which necessitates that you use a very small aperture to be sure that your subject is always in focus. It also suffers from the problem of dimensional distortion, as it is similar to the wide-angle lens in terms of the result, and that is why you have to pay attention when it is

Your subject is too close to the lens from