Motion control photography is a technique used in still photography and motion that allows accurate control, and optionally also allows repetition, camera movement. This can be used to facilitate special effects photography. This process can involve taking multiple elements using the same camera movement, and then merging elements into a single image. Other effects are often used in conjunction with motion controls, such as chroma buttons to aid composition. The camera motion control rig is also used in still photography with or without compositing; eg in long exposures of moving vehicles. Current computer technology allows programmed camera movements to be processed, such as moving scales up or down for different sized elements. Common applications of this process include miniature shooting, whether to combine several miniatures or into composite miniatures with full-scale elements.
This process is also commonly used when duplication of elements that can not be physically duplicated is required; Motion control is the main method of displaying multiple instances of the same actor in a shot that involves camera movement. For this technique, the camera usually records exactly the same movements in the exact same location while the actor performs a different part. Fetching blank (without actors in shooting) is sometimes also taken to illustrate to the drawer what part of the shoot is different in each shoot. This, in the common film making language, is also known as the "plate shooting".
In today's film, the reference taken is also useful for digital manipulation of shooting, or for adding digital elements. A simple duplicate shot limits each "copy" of an element to a single portion of the screen. Much more difficult to combine shots when duplicate elements cross paths, though digital technology has made this easier to achieve. Some basic camera tricks are sometimes used with this technique, such as having a hand twice insert a shot to interact with an actor while a duplicate arm is out of the screen. For the sake of compositing, the background elements of the scene must remain identical between shoots, requiring anything that can be moved to be locked; Fetching blank references can help in resolving any differences between other photographs.
Similar technology in modern films allows the camera to record precise movements during shooting so that movement can be duplicated by the computer in the creation of computer generated elements for the same shooting.
Video Motion control photography
History
Modelmaking for scenery has long been used in the film industry, but when the model is too small it often loses its illusion and becomes a "clear model". Solving this by building larger models introduces a dilemma: larger models are harder to build and often too fragile to move smoothly. The solution is to move the camera, rather than the model, and the appearance of a compact 35mm compact camera has made motion controls a machine-worthy control. Motion control also requires control over other photographic elements, such as frame rate, focus, and shutter speed. By changing frame frequency and depth of field, the model can look much larger than it really is, and camera motion speed can be increased or lowered.
Early attempts at motion control emerged when John Whitney pioneered some movement techniques using an old anti-aircraft analogue computer (Kerrison Predictor) connected to the servos to control lights and lighted targets. The film Catalog (1961) and his sister film James Whitney Lapis (1966) were both accomplished with John's pioneer movement control system. The 1968 film 2001: A Space Odyssey spearheaded motion in two ways. Photography of this film model is performed with a large mechanical rig that enables precise and repeatable camera and model movements. The final of the film is made with mechanically controlled slit-scan photography, which requires precise camera motion control during single frame exposure. The first large-scale motion control app is in Star Wars (1977), where a digitally controlled camera known as Dykstraflex performs complex and repetitive motions around a stationary spacecraft model. This allows greater complexity in battle-space circuits, as separate elements filmed (spacecraft, background, etc.) can be better coordinated with each other by greatly reducing errors.
In the UK The Moving Picture Company has the first practical motion control rig. Designed and built on its own, it uses the IMC operating system to control its various axis movements. Peter Truckel operated it for several years before leaving him to pursue a career as a successful commercial director.
The simultaneous increase in the power and affordability of computer-generated imagery in the 21st century, and the ability of CGI specialists to duplicate handheld camera movements (see Suitable Movements), initially made the use of motion control photography less common. But film producers and directors have realized the cost savings benefits of using motion control to achieve the effect in a reliable and realistic way. CGI is still struggling to be 100% photorealistic, and the time and cost to achieve photo-realistic far exceeds the cost of shooting from the live action itself.
With 3D awakening as a medium movement control also has an important role to play, especially in the production of 3D backplate in scaled circuits. Using high resolution camera, the background can be easily taken for further use with live action and CGI character animation.
Maps Motion control photography
See also
- Dykstraflex
- Motion capture, motion recording process
- Milo Motion Control Rig
Note
Source of the article : Wikipedia
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