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【Concept】 Dual camera, dual-lens reflex camera means. Called the twin-lens reflex viewfinder lens reflex viewfinder type camera. Single, double, refers to the camera, that is a single-lens reflex, or twin-lens reflex. Now we are more familiar with the SLR, SLR is a camera, two lenses is dual. English abbreviation TLR ========================= 【History term】 Dual camera originated 130 years ago, and its development process can be divided into two periods, one before World War II, the second is the post-war. German dual camera, including RolleiFlex, Rolleicord and Ikoflex belong to the former Japanese dual camera, dual like Ricoh, Mamiya C330, belongs to the latter. ---------------
1. It is said that the original shape of the double-reverse camera is bunk house style camera. The camera is called the "Reporter", for the time being it translated as "reporter." It was in 1872 in London, England produced, dating back over 137 years. For such an old camera, then we may not be able to imagine how much time it takes to do it now seems very simple operations, such as in the focusing screen up to adjust the position of the subject, focus or just replace the cassette, release the shutter, etc. and so on. Of course, that time in order to take moving objects, it is more difficult. Although the "reporter" was not yet using the camera mirror device, but its overall look away from our common dual camera later style is not far off. ---------------
2. Probably in 1880, some of London's weather observer in order to shoot the clouds of heaven, they think of a way, that is placed in the camera in a mirror reflection to the clouds, so that when people do not have the viewfinder old upturned neck look days, but just look ahead focusing screen on it! But do not underestimate this improvement, which was the people in the first attempt to set up a camera in the mirror, oh. Because it is made for the camera while shooting the clouds, so people call it "the cloud machine", a great technological innovation, so it was born! In the cloud machine, two shots from the middle of the gear unit linked together, allowing movement of the lens to achieve synchronization. Moreover, the image on the focusing screen because of the mirror and become erect, you know, before the mirror in there, the image is inverted. Cloud machine, is considered a prototype dual camera directly, of course, there are some problems cloud machine is, for example, the body is too great, very practical, and there are serious parallax, not close-range photography, and so on. However, in any case, the significance of the cloud machine in the history of the camera will not be obliterated, because it opens a new chapter in the development of the camera! =========================
【Principle term】 --------------- 1. As the name suggests, the biggest feature is the TLR system has two lenses, one directly above one another in. The following lenses that transmit images to the film, but the image just above the lens is transmitted for framing and focusing. People can see the image through the lens above, but in fact only the following lenses really shooting for. --------------- 2. Typical TLR camera using a 120 or 220 roll film film, produce side length of 6 cm square negatives. When using TLR camera, generally waist level under way to hand it to watch frosted glass viewfinder. The image seen on the ground glass is 6 × 6 cm; and the right image in the vertical direction, but the left-right direction is reversed. Because two mirror viewfinder image is the result of reflection after the first formed. ========================= 【Advantages Terminology】 1. Traditional dual lens camera, is used for filming, one for imaging. But generally can not replace the lens, two lenses together, if not replace, then viewing and imaging lens parallax would be great. 2. There is a dual-lens camera imaging feature is the viewfinder lens is often seen in the image on the film with an imaging lens recorded different, there is a disparity. 3. When the viewfinder is too much trouble, it is difficult in focus, have started a magnifying glass to see the viewfinder. If you use it well, and almost SLR camera imaging. 4. Because dual camera viewfinder when the photographer looking down, so when the portrait photography can alleviate the subject's unnatural performance. 5. SLR cameras (SLR) In contrast, dual camera (TLR) camera for more than a viewfinder, mirror is fixed, and thus do not affect the photo exposure during shooting (SLR cameras due to lift and mirror cover the viewfinder screen, invisible image exposure period). Exactly the same on the frosted glass of imaging and film imaging size. =========================
【Term Disadvantages】 1. Since the viewfinder lens and photographic lenses are separated, and the next shaft framing cameras, TLR parallax problem (ie not WYSIWYG). When shooting close objects evils of this problem will become more apparent. So some modern TLR camera viewfinder built into the system automatically parallax compensation device. 2. Compared with the optical viewfinder or rangefinder, frosted glass on the image is not very bright. 3. You must watch the way down to waist level in front of the object will make the operation very convenient. Modern TLR camera adds a called Polo (Porro) eye-level viewfinder viewfinder accessory, can overcome this shortcoming. The twin-lens system on its inherent characteristics, the larger, and when changing lenses, you need to replace two lenses simultaneously; This is great for today's fast aperture lenses, it is indeed a problem. 5. lens interchangeability limited. If you replace the camera lens, you must also replace the viewfinder lens. Today's TLR cameras typically offer interchangeable twin-lens system. =========================
【Dual vs SLR term】 1. The twin-lens reflex camera lens reflex camera later sheets instead, mainly because of the SLR camera and imaging with a small viewfinder parallax, small, interchangeable lenses, film and easy. SLR camera imaging of high quality, the lens can be replaced, can take different shots for a variety of environments. Many more specialized control mode, conducive to the creation of a high level. Can accurately adjust the color temperature, sensitivity by adjusting the shutter aperture combination to achieve a variety of special effects, there are a variety of lenses can be exchanged with 2. The film has different specifications Dual Lens of general use 120 film, 135 film SLR general use. Previous 120 film imaging sophistication than 135 film badly, then the extent of 120 film professionals still improve a lot of delicate. 3. dual dual-lens reflex camera, a photography and framing shots were named because of framing and photography are two optical paths, there is disparity, with 120 film is relatively common. SLR is a single-lens reflex camera, framing and photography with the same lens, there is no parallax, 135/120 / Digital cameras have this structure. ========================= 【Article is excerpted from: Web Search】 【Reserved Integrate / Just Reference】 【Translation is by The Network】 |
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