Four kinds of lenses for shooting special photography themes

Sometimes in order to shoot some special photographic subjects, we will use some specially constructed lenses, and the photos taken by these lenses are also quite interesting. Today, I will introduce four of them to you:

First, the macro lens (macro lens)

Macro lens is actually a special lens for macro photography, with high magnification, which is mainly used to shoot very fine objects, such as flowers and insects.

The so-called lens magnification refers to the ratio of the image on the photosensitive element to its real size. Usually, the lens magnification must reach 1: 1 to be called macro lens. The macro lens has a short focusing distance, so it can shoot the object at close range, which can enlarge the object.

Macro mirrors have several characteristics.

Foot end

Macro lenses are usually fixed-focus lenses. The focal length of the common macro lens in the market is usually around100 mm. Under the same magnification, the lens with long focal length can shoot farther than the lens with short focal length, which is more suitable for ecological shooting. On the contrary, if it is used to shoot dead objects or portraits, you can use a lens with a shorter focal length.

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At high magnification (such as near 1: 1), the lens will lose light seriously, so the maximum aperture value will decrease when focusing at close range.

If you just want to try macro fun and don't want to waste money on a macro lens, you can also use other methods. For example, add an extension tube between the camera lens and the fuselage or add a magnifying filter at the front end of the lens to achieve close-up effect. The former shortens the closest focusing distance by changing the structure of the fuselage, which has little effect on the imaging quality; The latter principle is to add a magnifying glass to the lens to enlarge the image, but because of the filter, the influence on the image quality is definitely greater than the former. Don't want to use money? You can try to play back the lens on the computer (fixed by hand or fixed by anti-ring), and you will be surprised.

Second, the Fisheye lens (fisheye lens)

Fish-eye glasses are a special kind of ultra-wide-angle lenses, and the general viewing angle is close to or equal to 180 or even higher.

A good wide-angle lens will have better deformation control than a wide-angle lens with the same wide field of view, while fisheye glasses, on the other hand, have serious barrel deformation, that is, the imaging becomes more and more "round". This is the special visual effect of fisheye glasses.

Fisheye glasses are usually fixed-focus lenses, and there are two main types, including:

Circular fisheye: The captured image is circular.

Quan Huafu fisheye: A common fisheye. The image taken is a normal square.

Three. Axis moving mirror

Axis-shifting lens is a lens that changes the direction and position relative to the image sensor in the lens structure. Generally speaking, the lens and the sensor are parallel on the same plane. With this lens, it can be tilted or moved in different directions, thus changing the whole focal plane, which is the so-called Scheimpflug principle.

The shift lens is standing on the ground when shooting the building. In order to take a complete picture, the camera should be tilted slightly upward. Because the lower part of the building is close to the upper part and far from the upper part, the convergence effect of "the lower part is big and the upper part is small" will be adopted. The lens itself is not deformed, and the reason for this phenomenon is the perspective relationship. Shift-axis lens can be used to correct perspective problems.

The axis-shifting mirror has two main functions: "shifting" and "tilting", which allows you to move the mirror axis and adjust the perspective lens.

I believe many people have tried to "move up" or "move down" according to different needs, but at the same time, you will find that the imaging will be seriously deformed (for example, the head will be big and the body will be thin when taking portraits). This change needs to be avoided as much as possible, especially in architectural photography. Therefore, the offset function of the axis shifting mirror can enlarge the imaging circle and improve the modification. The tilt angle function can adjust the depth of field of imaging.

However, due to the complex mechanical structure, it needs a larger field of vision and back row working space, so the price will be relatively high. The most common way to play with the shift mirror is to take miniature photography to make a city look like a model.

Fourth, rangefinder.

Magnifier (also called extended-range lens or telephoto zoom lens) is an optical accessory installed between the lens and the camera body. It can enlarge the image. Magnifier has different magnifications. A 2-fold magnifying glass can double the size of the image, that is, the focal length of the lens can be effectively doubled after installation.

The rangefinder is an optical element installed between the fuselage and the mirror to increase the focal length of the lens. Compared with buying a lens with a longer focal length, the range extender will be much cheaper, and its small size makes the range extender lighter than a telephoto lens. However, relatively speaking, because the number of lenses through which light enters the photosensitive element from the lens increases after installing the rangefinder, there will inevitably be side effects of reducing the imaging quality. At the same time, the amount of light will decrease after installing the rangefinder, so the lens aperture will become smaller after installing the rangefinder. ?

Rangefinder can be divided into magnification. Generally, it is 1.4x, 1.7x, 2x, etc. Multiplying the focal length of the original lens by the magnification is the focal length of the lens after installing the rangefinder. If a magnifying glass is attached to a 50mm lens, the obtained image will be the same size as that taken by a 100mm lens; If it is installed on a 200mm lens, you will get the image size produced by a 400mm lens, and so on.

Photography is a continuous creative process. When you encounter a bottleneck in the creative process, or can these four special lenses give you a little other idea?