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Professionalsia High speed camcorders from Redlake (USA) Alexander Markelov High speed video shooting is originated from high speed filming and takes over part of its tasks such as a registration and visualization of processes, which are carried out very rapidly. Conditionally these processes can be divided into three groups:
Obviously that suppressing majority of the tasks pertain to scientific studies though it is impossible throw with count and advertising shootings. Does not exist nor one instrument, which was fit for decision of all enumerated tasks, because a range of the motion object velocities is too great. But the used instruments it is possible to group. If we should tell about filming, then for decision of the tasks of the first group a motion-picture camera with discrete film movement is used; of the second group — the motion-picture cameras with prism and mirror movement compensation are used; of the third — cameras with mirror picture scanning and still film are used. The first high speed camcorders on principle of the action looked like speed motion-picture cameras; so a tape in video recorder was forced to move with high velocity. Herewith frequencies were reached in several hundreds frames/sec. However, high velocity of the tape entails the greater dynamic loads on tape, with than faced else when designing and production of the speediest motion-picture cameras (these problems limit the frame rates). Fortunately, with the exception of film and tape other receivers of information are existed. In general the information carriers are photons. The problem of the modern high speed systems for registration of high speed processes is concerned to photonics (the official name is high speed photography and photonics, HSPP). So, for instance, for photonics from 1960 the positional storage system is known. At present as receivers of information CCD are used most broadly. The modern speediest camcorder quite does not contain the moving parts, but maximum frame rate and resolution are defined by information capacity of CCD. The modern speediest camcorders are suitable to solve the tasks of the second group. On quality of the picture they while several lose to motion-picture cameras, but technology production for receivers of radiation constantly develops and video picture quality are raised constantly. Here appropriately say about one important advantage of the camcorders before motion-picture cameras. Much often before shooting the features of high-speed process it is not enough known (e. g., a necessary speed of shooting is unknown). At shooting by motion-picture camera the exposed film will be subject to photo-chemical processing in laboratory (which is placed sometime very far from the shooting area) and only after this action it is possible to define, if parameters of the shooting were chose correctly. In bad case the shooting must be repeated. Videoshooting can be repeated how much are pleased once, results are valued on place, if required corrections are contributed. The place of interest is combination of videoshooting and filming. Videoshooting is used as pilot for study of shooting process parameters, but filming is used for receiving of the qualitative result. Is known that many companies which produce professional television equipment have been conducting active work making the TV camcorders for high speed shooting. However is known that increase of video recording speed inevitably conducts to loss quality of picture. This is explained that that in existing for present-day day photosensitive matrix CCD and CMOS the rate of reading, processing and data communication in storage device it is not enough high. With increase of the shooting speed the frequency of the frames (shooting speed) it is necessary to reduce the number a working pixels in the matrix, participating in image forming. So scanned area of the picture is decreased. Naturally, this effect leads to reduction of the “picture” quality. But while this is done exactly so. For this reason in present time the possibility of the high speed shooting in digital cinematographer is limited. Come up for near-by past the professional camcorder HDW-F900 by Sony company has done the possibility of digital speed shooting with broadcasting quality. In this camcorder CCD are used (1920×1080), which give beautiful resolution of picture, but do not allow to raise the frequency of the frame change more than 30/sec under progressive scanning and more than 60 fields/sec at interlacing scanning. More simply, the speed of shooting and video recording increases no more than three times. This, certainly, enables the speed shooting and slow reproducing the picture, but for majority of the events, where high speed shooting is required, these frequencies turns out to be it is not enough. For instance, for high speed advertising shooting in most cases recording rates from 100 to 500 frames/sec are used. For event shooting, occupying decimals of a second, rates from 500 to 1000 frames/sec are required. As for high speed processes, which happens during scientific studies, they are occurred during some hundredth or thousandth of a second and even more short gap of time. Obviously that here are necessary to have much more high shooting rates and usual television camcorders for these integer do not approach. In principal for experimenters it is important to see and understand that real occurs during that or other high speed process, rather then build its functioning on guesswork. In histories of physical experiment is the information about that, how and what for were made the first shootings by mechanical high speed camera. Once upon a time in passion of the philosophical polemics Austrian physicist-philosopher Ernst Mach (1838-1916) has asked its buddy: “But you really believe that artillery shell exists in flight? Did you see it? Can be, in general it disappears after shot from gun and then appears beside purposes only, where order him to turn out to be by the laws of mechanics?” The flabbergasted buddy has answered him by rotation of finger beside temple that was not shown for Mach as convincing counter argument. So Ernst Mach has constructed the special mechanical high speed motion-picture camera and the first in the world was able to get the picture of the artillery shell in flight. Yes, the shell had have existed, and is fixed on these pictures. Moreover, on these pictures an enigmatic dark “moustaches” were fixed, dispersing in parties and from nose of the shell back. This first high speed shooting enabled to understand that dark “moustaches” is a cone of the shock wave (now named by Mach cone), which is the shell produced by moving at the speed of above velocities of the sound midair. Also, this shooting helped to tie together the corner of the cone (the corner of the Mach) with ratio of the shell speed to the sound speed (the Mach number).
The experience of Austrian physicist was a beginning of the scientific studies, in accordance with using the high speed cameras of different types. With the time mechanical speed motion-picture cameras all more delivered the positions before onslaught of the TV camcorders. At present universally recognized leader in the field of production of the speediest TV cameras for registration of high speed processes is Redlake Company (USA). Application of these cameras (their speed is up to 100,000 frames/sec) allows seeing on screen of the computer the phenomena, imperceptible for eye and not perceived by usual TV camcorder. Moreover, specialized equipment and software, proposed by Redlake, allows to conduct the operative computer analysis for motion parameters of investigation object (the coordinates, velocity, acceleration etc.) in manual and automatic mode. The equipment range, proposed by Redlake Company for ensuring speediest and other special shootings, is very wide; so here is the information about the most wide-spread speediest devices.
Motion MeterThis is a small television camcorder, reminding digital camera with liquid-crystal screen on back wall, is intended for visual control of picture. It is very suitable for operative observation for production process, particularly if installation of stationary high-speed camcorder is not possible and shooting with hands is required. The resolution of the camcorder is enough for video documenting of facts of the technology breach in industry under high velocity of the equipment (for instance, on production lines). Recording can be synchronized from external source (standard TTL-signal). Power supply: network 220 V or source of the direct current 12 V. Mode of the playback is either frame-by-frame or with controlled velocity from 1 to 1000 frames/sec onward and back. Duration of continuous recording under resolution 292×220 is up to 4 sec.
Motion Meter is a comparatively inexpensive camcorder. So she wholly acceptable for laboratory of the different educational institutions, scientific and research institutes, for shooting of sport events, processes in biomechanics etc. Some curious studies with using the similar camcorders have conducted by American scientists. The acoustics of the submarines know that when on the sea is rainy or snowy the special auditory device, used by submariners for finding the enemy, turn out to be absolutely useless. The same have noted by fishermen, when on them ships are installed the hydrophones, intended for fish jamb searching for. The American researchers having armed high-speed camcorder have done recording the falling process of the rain drops and snowflakes on the surface of water. Turned out to be that each drop, falling on water surface, leads away the blebs, which are bursting and create the noise under water. But when “land on water” snowflakes, blebs fall into water, burst and create the noise, which spreads in water much better, than in air. There was made the conclusion that almost all sounds, which in presentation of the people are connected with water, are indeed connected with blebs of the air. The boom of the waterfall is caused by them, noise by stone falling in water is the result of the forming the bubbles, and so on…
Motion Scope PCIThe Motion Scope PCI system is intended for high-speed recording and following detailed analysis of the motion processes. This system consists of a camcorder, a computer with special full-size PCI-board, made by Redlake Company, and connecting cable. Software applicable to camcorder, enables the formation of trajectory, as well as analysis of the velocity and acceleration of the shooting object on determined sections of the motion.
Due to software programs on base of the operating system Windows the application of this system is easy. One personal computer can unify up to four such systems with Motion Scope PCI camcorder, giving several types of the traced event. The camcorders Motion Scope PCI can be switched on and stopped with the help of portable board of remote control or by external controlling signal, generated optical, acoustic or electronic sensor (the standard signal is 5V TTL or signal of the direct current is up to 30V). After fixing the pictures of the event are found on Motion Scope PCI board in personal computer until they will not be translated on bus PCI for indication on screen and for analysis. The mode of the playback is frame-by-frame or onward and back with controlled velocity from 1 to 8000 frames/sec. The pictures are stored in format of the Microsoft standard file avi. They can be converted to other graphic formats. Each camcorder has the videosignal output for picture recording on videotape. For convenience of shooting the wide range of withdrawable lens with C-mount fastening is used. Motion Scope PCI is broadly used in scientific study in the field of aviations and astronautics, in analysis of the high-tech production processes, in military studies, in sports etc. Motion ProAs to Motion Pro system, that it is appeared relatively recently and, on essences, reminds the Motion Scope PCI system. However Motion Pro differs by use as photosensitive device of the new CMOS-matrix with high resolution (1280×1024 pixels) and high frame rate (up to 10000 frames/sec). Time record under maximum resolution is raised up to 10 sec. More additional possibilities gives the use standard removable lens with F-mount fastening (e. g., line of lens by Nicon) and new software. In particular, it is possible to correct the scale of the transmission of gray, chrominance, contrast etc. The “Daymler Kraysler” company, which have been carried out the next modification of the engines for Mercedes-Benz, have used so-called “glass” engine, where processes of the high-speed injection of fuel into cylinders were shooting by high-speed camcorder. As a result were designed some new high effect injectors and pumps for application in pressurized atmosphere.
New software enables supervision and analysis of the motion in planes and space. However for shootings and analysis in three-dimensional space the system needs to use already two camcorders and more. In the same way, either as in Motion Scope PCI system, in computer can be installed up to four full-size PCI boards produced by Redlake company. Crash-test is the experiment, which is carried out in obligatory order by all automotive companies. This experiment is discovered the consequence of car collisions with obstacle. Usually several high-speed camcorders are used for these experiments. For instance, 30 such camcorders are installed on target ground of Volvo. They are located around area of the collision. The experiments enable to see that comes of car and passengers (the mannequins) during collision for the thousandth of a second, and understand, what measures necessary to undertake for safety of the people, residing in machine.
HG-100KAbsolutely new development of Redlake company is a high-speed camcorder HG-100K. New CMOS-matrix, digital block of TV signal processing and storage device are placed inside case of the camcorder. This enabled to raise it speed up to 100,000 frames/sec. The full resolution is supported at shooting up to 1000 frames/sec. The perfect circuit of electronic shutter allows to shoot events with maximum speed and with exposure time equal to 5 µsec with minimum smearing of the picture in comparison with existing camcorders.
The Important particularity of this camcorder is that she capable to work in Ethernet. This enables to delete the camcorder from computer on the distance of 100 m and more. The camera head is capable to bear overloading and acceleration up to 100 g that does it one of most “shockproofed”. Possessing by all main advantages of the Motion Pro system, camcorder HG-100K has the best features on noise (62 dB) and on sensitivity (1600 ASA in black-and-white and 400 ASA in color). And Motion Pro and HG-100 K allow functioning in the most wide-spread formats of the picture recording: avi, bmp, tif, jpg and cfg. Both systems allow operatively to analyze the parameters of the investigation object motion (the coordinates, velocity, acceleration etc.). For this it is enough to assign the scale of the scene and install the marks on traced object. The programs are existed, which automatically trace the object moving in planes and space and fill the tables with coordinates of the object in movement. The Broad spectrum of the proposed equipment allows to work under vibration and great accelerations, under low luminosity and in IR range.
Application of the high-speed camcorders has allowed to the NASA scientists in USA for the first time to study the activity of lightning in the scale of Earth. Installed on NASA satellites the camcorders have registered that most “pet” area for lightning is a central Africa, where thunderstorms are all the year round, but in Arctic Zone and in Antarctic these phenomena are as exceeding rarity. In the field of military developments the Redlake camcorder allow the unique possibility to understand, finally, with constructive, technological and other problems unsolved earlier. At present these camcorders are successfully used for registration and analysis of the shock wave, trajectory change, collisions of high-speed objects, diagnostics and designing the high-speed machines. Material provided by INNKO Opto Company |
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