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[Concept]
Refers to the need to install a close-up lens, extension rings, or close-up close-up track bellows attachment can be used to dedicated cameras for macro or close photography. The macro lens effect diagram
A very close to the image size and subject the subject to focus the lens, macro lens is formed in the film or sensor size is almost equal.
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[Structure]
There are two general structure
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A built-in retractable tube]
In ordinary photography, the photographer can rotate the lens focusing ring will be able to carry out normal focus, if you want close-up, as long as we have been rotated to the recent focus at the focus ring continues to rotate the lens of the entire optical system purpose of the tube along with the built-in synchronization forward, so that the image distance increases, its close-up
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(2) exchange the lens optical lens group front and rear position]
To transform the position before and after the lens optical lens group to get a higher magnification of the image, so as to achieve the purpose of close-up
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To very close to the subject can be correctly focused on the distance, the macro lens is usually designed to be able to stretch out even longer, so that the optical center as far as possible away from the sensor, the design of the lens group, must also be focus on the close range of the deformation and color control.
Macro lenses are usually medium focal length lens, but it actually can be any focal length lens.
For example, both the 50mm macro lens, 180mm macro lens 70-180mm macro zoom lens.
Most of the macro lens focal length is greater than the standard lens, can be classified as a telephoto lens, but is not as good as a general telephoto lens on the optical design may therefore not fully applicable to the general photography.
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[Sub class]
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A macro lens (macrolens)
Refers to the reproduction ratio of about 1:1 lens.
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2 [micro focusing lens (macro-focusinglens)
Copy refers to the ratio between the 1:1.2-1:2 lens.
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[Near the focusing lens (close-focusinglens)
Copy refers to the ratio between 1:2-1:4 lens.
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The 1:1 labeled macro lens the size of the image with the subject in the film
1:2 mark indicates that the film image is half of the subject
2:1 said that 2 times the subject.
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【Properties】
A macro lens is usually a medium focal length lens, but in fact it can be any focal length lens, both 50mm macro lens, a 100mm macro lens
70-180mm macro zoom lens, lens labeled with the name of the macro, just to illustrate this lens in addition to determine the focal length of the normal lens function, compared with the average lens can also focus on a closer subject physical size of the image formed in the film.
Equivalent to the resolution and minimal distortion aberration, and contrast, excellent color reproduction and more expensive.
Macro lens for shooting small objects valuable, such as insects, flowers, stamps, and so on.
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[Use]
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[Select]
Different focal length macro lens, the different application characteristics, specifically:
(1) in the same like a field than the shorter the lens focal length perturbation from the closer; the larger picture in terms of the same photo from the longer the focal length of lens;
Short focal length lens can focus on the picture's sense of perspective, a long focal length lens compressible screen, fuzzy background, to better highlight the main.
3 In general, to be left in between the lens and the main larger space lighting, lighting, when to use the long focal length macro lens, shooting insects or other small animals should be used in the focal length is longer macro lens, shooting more distant from insects or small animals and prevented so that frightened miss the photo opportunity.
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[Exposure compensation]
Appropriate exposure compensation using the macro lens close-up, according to the shooting magnification macro lens manual recommend the appropriate exposure compensation data.
Most single-lens reflex camera with automatic exposure function when shooting Ji L function camera that has automatic exposure file, without the need for exposure compensation.
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[REC Quality]
Many zoom lens with macro shooting function (in the strict sense should be called "macro functions" or high-powered camera functionality, because the word standard MACRO zoom lens, high-magnification shooting distance when shooting is not very close), but with fixed focal length lens compared to the macro function is still a gap.
1 shooting ratio is small, generally 1:4 or even smaller (eg, maximum Macro magnification of a Nikon lens in the 200mm focal length is only 1:5.9 at the 80mm focal length is only 1:14 ), only a handful reach 1:2;
(2) image quality not as good as fixed focal length macro lens shooting with the zoom macro file.
Minolta AF Macro Zoom 3x-lx, f/1.7-2.8 is a special case of the zoom lens in the macro function, which is a macro zoom lens, macro capability than fixed focal length lens shooting magnification , 1 to 3 times the shooting magnification (zoom in), but can still autofocus when shooting high magnification shooting magnification, is the world's first high magnification auto-focus camera lens.
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[Precise focus]
Macro lens to take close shots of small objects provide a convenient, but using a macro lens for macro shooting, a very small depth of field, focus very carefully, and as the camera frame shooting tripod or remake the shelves.
Macro photography, the trick is to focus on to be accurate; macro photos of a clear focus range is very small, only one inch of a small part.
For example, shooting macro images of flowers the bees must ensure that the bees precise focus clear; assume that the distance from the lens to bee changed even less than 1/4 inches, will lose the sharp focus. Therefore, in the process of shooting a wonderful macro photo, focus is very grueling.
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【Article is excerpted from: Baidu Encyclopedia】
【Network reprint / Just reference】
【Translation is by Goolge】
