High speed photography 3582572 216780991 2008-06-03T04:47:31Z Firsfron 158443 clean up, it's->its using [[Project:AutoWikiBrowser|AWB]] [[Image:Muybridge race horse animated.gif|thumb|300px|Sequence of a race horse galloping. Photos taken by [[Eadweard Muybridge]], first published in 1887.]] '''High Speed Photography''' is the science of taking pictures of very fast phenomena. In 1948, the [[Society of Motion Picture and Television Engineers]] (SMPTE) defined high-speed photography as any set of photographs captured by a camera capable of 128 frames per second or greater, and of at least three consecutive frames. High speed photography can be considered to be the opposite of [[time-lapse photography]]. In common usage, high speed photography may refer to either or both of the following meanings. The first is that the photograph itself may be taken in a way as to appear to freeze the motion, especially to reduce [[motion blur]]. The second is that a series of photographs may be taken at a high sampling frequency or frame rate. The first requires a sensor with good sensitivity and either a very good shuttering system or a very fast strobe light. The second requires some means of capturing successive frames, either with a mechanical device or by moving data off electronic sensors very quickly. Other considerations for high-speed photographers are record length, [[Reciprocity (photography)|reciprocity]] breakdown, and [[Optical resolution|spatial resolution]]. == Early applications and development == {{Unreferencedsection|date=February 2008}} [[Image:Tumbler Snapper rope tricks.jpg|thumb|right|300px|Nuclear explosion photographed by [[Rapatronic camera]] less than 1 millisecond after detonation. The fireball is about 20 meters in diameter. The spikes at the bottom of the fireball are due to what is known as the [[rope trick effect]].]] The first practical application of high-speed photography was [[Eadward Muybridge]]'s 1878 investigation into whether horses' feet were actually all off the ground at once during a [[Trot (horse gait)|trot]]. [[Bell Labs|Bell Telephone Laboratories]] was one of the first customers for a camera developed by [[Eastman Kodak]] in the early 1930s. Bell used the system, which ran 16 mm [[Photographic film|film]] at 1000 frame/s and had a {{convert|100|ft|m|sing=on}} load capacity, to study [[Switch#Contact bounce|relay bounce]]. When Kodak declined to develop a higher-speed version, Bell Labs developed it themselves, calling it the Fastax. The Fastax was capable of 5,000 frame/s. Bell eventually sold the camera design to [[Western Electric]], who in turn sold it to the [[Wollensak Optical Company]]. Wollensak further improved the design to achieve 10,000 frame/s. [[Redlake Laboratories]] introduced another 16 mm rotating prism camera, the Hycam, in the early 1960s. [[Photo-Sonics]] developed several models of rotating prism camera capable of running 35 mm and 70 mm film in the 1960s. [[Visible Solutions]] introduced the Photec IV 16 mm camera in the 1980s. The [[D. B. Milliken]] company developed an intermittent, pin-registered, 16 mm camera for speeds of 400 frame/s in 1957. [[Mitchell Camera|Mitchell]], [[Redlake Laboratories]], and Photo-Sonics eventually followed in the 1960s with a variety of 16, 35, and 70 mm intermittent cameras. == Stroboscopy and laser applications == [[Harold Eugene Edgerton|Doc Edgerton]] is generally credited with pioneering the use of the [[stroboscope]] to freeze fast motion. He eventually helped found [[EG&G]], which used some of Edgerton's methods to capture the physics of explosions required to detonate nuclear weapons. See, for example, the photograph of an explosion using a [[Rapatronic camera]]. Advancing the idea of the stroboscope, researchers began using [[laser]]s to stop high speed motion. == High speed film cameras == [[Image:High speed photography.jpg|thumb|right|300px|A 5 milliseconds capture of coffee blown out of a straw]] [[Image:Michael Melgar LiquidArt resize droplet.jpg‎|thumb|right|300px|A droplet is caught with a strobe after rebounding upward]] As film and mechanical transports improved, the high-speed film camera became available for scientific research. Kodak eventually shifted its film from acetate base to Estar (Kodak's name for a [[Mylar]]-equivalent plastic), which enhanced the strength and allowed it to be pulled faster. The Estar was also more stable than acetate allowing more accurate measurement, and it was not as prone to fire. Each film type is available in many load sizes. These may be cut down and placed in magazines for easier loading. A {{convert|1200|ft|m|sing=on}} magazine is typically the longest available for the 35 mm and 70 mm cameras. A {{convert|400|ft|m|sing=on}} magazine is typical for 16 mm cameras, though {{convert|1000|ft|m|sing=on}} magazines are available. The images on 35 mm high-speed film are typically rectangular with the long side between the sprocket holes instead of parallel to the edges as in standard photography. 16 mm and 70 mm images are typically square rather than rectangular. A list of [[American National Standards Institute|ANSI]] formats and sizes is available. === Intermittent pin register === The intermittent pin register camera actually stops the film in the [[film gate]] while the photograph is being taken. In high-speed photography, this requires a complex mechanism for keeping the film moving quickly through the camera from the supply [[reel]], but then stopping it for imaging, and then starting it again to move it onto the takeup reel. In many cases, a loop is formed before and after the gate to create and then take up the slack. ''Pull-down claws'' grab the film and move it into place and then move it back out of the film gate after the exposure. ''Register pins'' secure the film while it is being exposed. In some cases, vacuum [[suction]] is used to keep the film, especially 35 mm and 70 mm film, flat so that the images are in focus across the entire frame. * 16 mm pin register: D. B. Milliken Locam, capable of 500 frame/s; the design was eventually sold to Redlake. Photo-Sonics built a 16 mm pin-registered camera that was capable of 1000 frame/s, but they eventually removed it from the market. * 35 mm pin register: Early cameras included the Mitchell 35 mm. Photo-Sonics won an [[Academy Award for Technical Achievement]] for the 4ER in 1988. The 4E is capable of 360 frame/s. * 70 mm pin register: Cameras include a model made by [[Hulcher]], and Photo-Sonics 10A and 10R cameras, capable of 125 frame/s. === Rotary prism === The rotary prism camera allowed higher frame rates without placing as much stress on the film or transport mechanism. The film moves smoothly past a rotating prism which is synchronized to the main film sprocket. Each revolution of the prism "paints" the same number of frames onto the film as there are faces on the prism. A shutter also improves the results by only opening as the prism faces are nearly parallel, and then closing again. * 16 mm rotary prism - Redlake Hycam and Fastax cameras are capable of 10,000 frame/s with a full frame prism (4 facets), 20,000 frame/s with a half-frame kit, and 40,000 frame/s with a quarter-frame kit. Visible Solutions also makes the Photec IV. * 35 mm rotary prism - Photo-Sonics 4C cameras are capable of 2,500 frame/s with a full frame prism (4 facets), 4,000 frame/s with a half-frame kit, and 8,000 frame/s with a half-frame kit. * 70 mm rotary prism - Photo-Sonics 10B cameras are capable of 360 frame/s with a full frame prism (4 facets), and 720 frame/s with a half-frame kit.. === Rotary mirror === The [[Cordin]] Dynafax held a strip of film still while a mirror rotated at high speeds. At the appropriate moment, the capping shutter was opened and the mirror steered images onto the film. This type of system was capable of 1,000,000 frame/s for a few hundred frames. More recent rotating mirror cameras have achieved speeds in excess of 3,000,000 frame/s and have taken advantage of CCDs (see below), providing the end user with immediate results from their photographed events. == Streak, shadowgraph, and motion compensation photography == By removing the prism from the rotary prism cameras and using a very narrow slit in place of the shutter, it is possible to take images whose exposure is proportional to the film speed across the slit. The image that results has several useful properties. The film advance direction is essentially a measure of time. If the subject's motion is perpendicular to the slit, it may show growth or motion perpendicular to the slit. When the motion of the film is opposite to that of the subject with an inverting (positive) lens, and synchronized appropriately, the images show events as a function of time. Objects remaining motionless show up as streaks. This is the technique used for finish line photographs. At no time is it possible to take a still photograph that duplicates the results of a finish line photograph taken with this method. A still is a photograph ''in'' time, a streak photograph is a photograph ''of'' time. By combining this technique with a diffracted wavefront of light, as by a knife-edge, it is possible to take photographs of phase perturbations within a homogeneous medium. For example, it is possible to capture shockwaves of bullets and other high-speed objects. See, for example, [[Shadowgraph]] and [[Schlieren photography]]. == Video == Early video cameras using [[Video camera tube|tubes]] (such as the [[Video camera tube#Vidicon|Vidicon]]) suffered from severe "ghosting" due to the fact that the latent image on the target remained even after the subject had moved. Furthermore, as the system scanned the target, the motion of the scanning relative to the subject resulted in artifacts that compromised the image. The target in Vidicon type camera tubes can be made of various photoconductive chemicals such as [[antimony sulfide]] ([[antimony|Sb]]<sub>2</sub>[[sulfur|S]]<sub>3</sub>), [[lead(II) oxide]] ([[lead|Pb]][[Oxygen|O]]), and others with various image "stick" properties. The [[Philo Farnsworth|Farnsworth]] ''Image Dissector'' did not suffer from image "stick" of the type Vidicons exhibit, and so related special image converter tubes might be used to capture short frame sequences at very high speed. The mechanical shutter, invented by [[Pat Keller]], et al., at [[China Lake]] in the 1980s, helped freeze the action and eliminate ghosting. This was a mechanical shutter similar to the one used in high-speed film cameras—a disk with a wedge removed. The opening was synchronized to the frame rate, and the size of the opening was proportional to the integration or shutter time. By making the opening very small, the motion could be stopped. Despite the resulting improvements in image quality, these systems were still limited to 60 frame/s. === CCD === The introduction of the [[Charge-coupled device|CCD]] revolutionized high-speed photography in the 1980s. The ''staring array'' configuration of the sensor eliminated the scanning artifacts. Precise control of the integration time replaced the use of the mechanical shutter. However, the CCD architecture limited the rate at which images could be read off the sensor. Most of these systems still ran at [[NTSC]] rates (approximately 60 frame/s), but some, especially those built by the Kodak Spin Physics group, ran faster and recorded onto specially constructed video tape cassettes. Eventually, the Kodak group managed to develop the HG2000, a camera that could run at 1000 frame/s with a 512 x 384 [[pixel]] sensor for 2 seconds. By adding an [[image intensifier]] to a CCD, it is possible to capture a single frame of a very fast event. [[DRS-Hadland|Hadland]] uses this technique for a range of high-speed cameras capable of running at 1,000,000 frame/s, though record lengths are limited to 8 or 16 images. More recently, Specialised Imaging Limited[http://www.specialised-imaging.com] introduced a high speed camera that was capable of running at 200,000,000 frame/s with up to 32 images. === CMOS === The introduction of [[CMOS]] sensor technology again revolutionized high-speed photography in the 1990s and serves as a classic example of a [[disruptive technology]]. Based on the same materials as computer memory, the CMOS process was cheaper to build than CCD and easier to integrate with on-chip memory and processing functions, though the image quality and quantum efficiency of CCD still compare favorably. The first patent of an Active Pixel Sensor (APS), submitted by [[JPL]]'s [[Eric Fossum]], led to the [[spin-off]] of Photobit, which was eventually bought by [[Micron Technology]]. However, Photobit's first interest was in the standard video market; the first high-speed CMOS system was [[NAC Image Technology]]'s HSV 1000, first produced in 1990. [[Vision Research]] uses a CMOS sensor in the Phantom v4 camera, with a sensor designed at the [[Belgium|Belgian]] [[Imec|Interuniversity Microelectronics Center]] (IMEC). These systems quickly made inroads into the 16 mm high-speed film camera market despite resolution and record times (0.25 [[pixel| megapixel]], 4 s at full frame and 1000 frame/s) that suffered in comparison to existing film systems. IMEC later spun the design group off as [[FillFactory]], which was later purchased by [[Cypress Semiconductor]]. Photobit eventually introduced a 500 frame/s 1.3 [[pixel| megapixel]] [http://www.micron.com/products/imaging/applications/machinevision.html sensor], a device found in many low-end high-speed systems. Subsequently, several camera manufacturers compete in the high speed digital video market, including AOS Technologies, Fastec Imaging, NAC, Olympus, Photron, Redlake, Vision Research, and Weinberger, with sensors developed by Photobit, Cypress, and in-house designers. As at January 2008, Vision Research's Phantom HD camera capable of 1920 x 1080 pixel resolution (Sony Hi-Def) has replaced a few 16 mm film cameras in some media applications and has replaced 35 mm film cameras in a few commercials in the UK. Most UK commericals are now show using the ARRI "Tornado", which is based on the Memrecam K5 from NAC Image Technology. This is the camera of choice for media application due to its unparalled light sensitivity afforded to it by its large pixels. <!--- I suggest a table with available formats, i.e. mfg, model, year introduced, pixels, rates, record times, pix sizes & pitch - Ehusman ---> In addition to those science and engineering types of cameras, an entire industry has been built up around industrial machine vision systems and requirements. The major application has been for high-speed manufacturing. A system typically consists of a camera, a [[frame grabber]], a processor, and communications and recording systems to document or control the manufacturing process. === Infrared === High-speed infrared photography has become possible with the introduction of the Amber Radiance, and later the Indigo Phoenix. Amber was purchased by [[Raytheon]], the Amber design team left and formed Indigo, and Indigo is now owned by [[FLIR Systems]]. [[Santa Barbara Focal Plane]], [[CEDIP]], and [[Electrophysics]] have also introduced high-speed infrared systems. == References == * {{cite book | author=Edgerton, Harold E., and Killian, James R. | title= Flash!: Seeing the Unseen By Ultra High-speed Photography | date=1939 | id= ASIN B00085INJ}} * {{cite book | author=Edgerton, Harold E. | title=Electronic flash, strobe | edition= 3rd Ed | Publisher= MIT Press, | location= Cambridge, MA | date= 1987 | id= ISBN 0-262-55014-8 }} * {{cite journal | author=Pendley, Gil | title=High-Speed Imaging Technology; Yesterday, Today & Tomorrow | journal= Proceedings of SPIE; 25th International Congress on High-Speed Photography and Photonics | volume= 4948 | pages = 110–113 | editor=Claude Cavailler, Graham P. Haddleton, Manfred Hugenschmidt | year= July 2003 }} * {{cite book | author=Ray, S. F. | title= High speed photography and photonics | publisher=Focal Press | location= Oxford, UK | date= 1997}} * {{cite book | author= Settles, G. S. | title= Schlieren and shadowgraph techniques: Visualizing phenomena in transparent media | location= Berlin | publisher= Springer-Verlag | id= ISBN 3-540-66155-7 | date= 2001}} == See also == * [[High speed camera]] * [[slow motion]] (less advanced than high-speed photography) == External links == * [http://www.pirate.co.uk/en/node/266 Lighting for High Speed TV and Film Shoots] Useful tips on lighting by Pirate * [http://www.autoliv.com.au/highspeedvideo.html High Speed Photography and Video] * [http://www.engr.colostate.edu/~dga/high_speed_video/ David Alciatore's] collection of high speed video clips * [http://www.rit.edu/~andpph/ Andrew Davidhazy]'s collection of streak photography applications, [http://www.rit.edu/~andpph/text-hs-overview.html overview] of high speed imaging, and [http://www.rit.edu/~andpph/text-ichspp_xx_paper.html High Speed 101] * [http://www.rit.edu/~andpph/text-hs-history.html A history] of early (19th century) high speed photography by Lincoln Endelman * [http://osa.org/ OSA] - The Optical Society of America * [http://spie.org/ SPIE] - The Society of Photo-Instrumentation Engineers * [http://www.imec.be/ IMEC] - a Belgian research consortium * [http://www.mne.psu.edu/PSGDL The Penn State University Gas Dynamics Lab], showing high-speed schlieren and shadowgraph imaging research * [http://www.liquidartgallery.com/ Liquid Art] - High speed photography as art. A collection of droplet photos * [http://www.lucidmovement.com/ Lucid Movement] - Daily high speed videos. * [http://www.liquid.backdrops.co.uk Liquid in Motion]. High speed photography of water droplets * [http://www.mikrotron.de/index.php?en_hsv_kamerabegriffe High Speed Camera Terminology] [[Category:Optics]] [[de:Hochgeschwindigkeitsfotografie]]