A high-speed camera is a device capable of capturing moving images with

exposures Exposures can refer to: *'' Andy Warhol's Exposures'' *'' Exposures – In Retrospect and Denial'' *The Exposures, a stage name of German electronic musician Jan Jelinek Jan Jelinek is a German electronic musician who also operates under the nam ...

of less than second or frame rates in excess of 250

frames per second A frame is often a structural system that supports other components of a physical construction and/or steel frame that limits the construction's extent. Frame and FRAME may also refer to: Physical objects In building construction *Framing (co ...

. It is used for recording fast-moving objects as photographic images onto a storage medium. After recording, the images stored on the medium can be played back in

slow motion Slow motion (commonly abbreviated as slow-mo or slo-mo) is an effect in film-making whereby time appears to be slowed down. It was invented by the Austrian priest August Musger in the early 20th century. This can be accomplished through the use ...

. Early high-speed cameras used

photographic film Photographic film is a strip or sheet of transparent film base coated on one side with a gelatin photographic emulsion, emulsion containing microscopically small light-sensitive silver halide crystals. The sizes and other characteristics of the ...

to record the high-speed events, but have been superseded by entirely electronic devices using an

image sensor An image sensor or imager is a sensor that detects and conveys information used to form an image. It does so by converting the variable attenuation of light waves (as they refraction, pass through or reflection (physics), reflect off objects) into s ...

(e.g. a

charge-coupled device A charge-coupled device (CCD) is an integrated circuit containing an array of linked, or coupled, capacitors. Under the control of an external circuit, each capacitor can transfer its electric charge to a neighboring capacitor. CCD sensors are a ...

(CCD) or a MOS

active pixel sensor An active-pixel sensor (APS) is an image sensor, which was invented by Peter J.W. Noble in 1968, where each pixel sensor unit cell has a photodetector (typically a pinned photodiode) and one or more active transistors. In a metal–oxide–semico ...

(APS)), typically recording over 1 000

onto

DRAM Dram, DRAM, or drams may refer to: Technology and engineering * Dram (unit), a unit of mass and volume, and an informal name for a small amount of liquor, especially whisky or whiskey * Dynamic random-access memory, a type of electronic semicondu ...

, to be played back slowly to study the motion for scientific study of transient phenomena.

Overview

A high-speed camera can be classified as: # A high-speed film camera which records to film, # A high-speed video camera which records to electronic memory, # A high-speed framing camera which records images on multiple image planes or multiple locations on the same image plane (generally film or a network of CCD cameras), # A high-speed streak camera which records a series of line-sized images to film or electronic memory. A normal

motion picture A film, also known as a movie or motion picture, is a work of visual art that simulates experiences and otherwise communicates ideas, stories, perceptions, emotions, or atmosphere through the use of moving images that are generally, since ...

film is played back at 24

, while television uses 25 frames/s (

PAL Phase Alternating Line (PAL) is a color encoding system for analog television. It was one of three major analogue colour television standards, the others being NTSC and SECAM. In most countries it was broadcast at 625 lines, 50 fields (25 ...

) or 29.97 frames/s (

NTSC NTSC (from National Television System Committee) is the first American standard for analog television, published and adopted in 1941. In 1961, it was assigned the designation System M. It is also known as EIA standard 170. In 1953, a second ...

). High-speed film cameras can film up to a quarter of a million fps by running the film over a rotating

prism PRISM is a code name for a program under which the United States National Security Agency (NSA) collects internet communications from various U.S. internet companies. The program is also known by the SIGAD . PRISM collects stored internet ...

mirror A mirror, also known as a looking glass, is an object that Reflection (physics), reflects an image. Light that bounces off a mirror forms an image of whatever is in front of it, which is then focused through the lens of the eye or a camera ...

instead of using a shutter, thus reducing the need for stopping and starting the film behind a shutter which would tear the film stock at such speeds. Using this technique one second of action can be stretched to more than ten minutes of playback time (super slow motion). High-speed video cameras are widely used for scientific research, military test and evaluation, and industry. Examples of industrial applications are filming a manufacturing line to better tune the machine, or in the car industry filming a

crash test A crash test is a form of destructive testing usually performed in order to ensure safe design standards in crashworthiness and crash compatibility for various modes of transportation (see automobile safety) or related systems and compon ...

to investigate the effect on the crash dummy passengers and the

automobile A car, or an automobile, is a motor vehicle with wheels. Most definitions of cars state that they run primarily on roads, Car seat, seat one to eight people, have four wheels, and mainly transport private transport#Personal transport, peopl ...

. Today, the digital high-speed camera has replaced the film camera used for Vehicle Impact Testing.

Television series A television show, TV program (), or simply a TV show, is the general reference to any content produced for viewing on a television set that is broadcast via over-the-air, satellite, and cable, or distributed digitally on streaming plat ...

such as ''

MythBusters ''MythBusters'' is a science entertainment television series created by Peter Rees (producer), Peter Rees and produced by Beyond International in Australia. The series premiered on the Discovery Channel on January 23, 2003. It was broadcast in ...

'' and ''

Time Warp Time travel is a common theme in fiction, mainly since the late 19th century, and has been depicted in a variety of media, such as literature, television, and film. The concept of time travel by mechanical means was popularized in H. G. Wells' ...

'' often use high-speed cameras to show their tests in slow motion. Saving the recorded high-speed images can be time-consuming because , consumer cameras have resolutions up to four megapixels with frame rates of over 1,000 per second which will record at a rate of 11 gigabytes per second. Technologically these cameras are very advanced, yet saving images requires use of slower standard video-computer interfaces. While recording is very fast, saving images is considerably slower. To reduce the storage space required and the time required for people to examine a recording, only the parts of an action which are of interest or relevance can be selected to film. When recording a cyclical process for industrial breakdown analysis, only the relevant part of each cycle is filmed. A problem for high-speed cameras is the needed exposure for the film; very bright light is needed to be able to film at 40,000 fps, sometimes leading to the subject of examination being destroyed because of the heat of the lighting. Monochromatic (black and white) filming is sometimes used to reduce the light intensity required. Even higher speed imaging is possible using specialized electronic

(CCD) imaging systems, which can achieve speeds of over 25 million fps. These cameras, however, still use rotating mirrors, like their older film counterparts. Solid state cameras can achieve speeds of up to 10 million fps. All development in high-speed cameras is now focused on digital video cameras which have many operational and cost benefits over film cameras. In 2010 researchers built a camera exposing each frame for two trillionths of a second ( picoseconds), for an effective frame rate of half a trillion fps (

femto-photography Femto-photography is a technique for recording the propagation of ultrashort pulses of light through a scene at a very high speed (up to 1013 frames per second). A femto-photograph is equivalent to an optical impulse response of a scene and has ...

). Work supported by research grants in 2009 and 2010. Modern high-speed cameras operate by converting the incident light (

photons A photon () is an elementary particle that is a quantum of the electromagnetic field, including electromagnetic radiation such as light and radio waves, and the force carrier for the electromagnetic force. Photons are massless particles that ...

) into a stream of

electrons The electron (, or in nuclear reactions) is a subatomic particle with a negative one elementary charge, elementary electric charge. It is a fundamental particle that comprises the ordinary matter that makes up the universe, along with up qua ...

which are then deflected onto a

photoanode A "photoelectrochemical cell" is one of two distinct classes of device. The first produces electrical energy similarly to a dye-sensitized photovoltaic cell, which meets the standard definition of a photovoltaic cell. The second is a photoelect ...

, back into photons, which can then be recorded onto either film or CCD.

Uses in television

*The show ''

'' prominently uses high-speed cameras for measuring speed or height. *''

'' was centered around the use of high-speed cameras to slow things down that are usually too fast to see with the naked eye. *High-speed cameras are frequently used in

television production A television show, TV program (), or simply a TV show, is the general reference to any content produced for viewing on a television set that is broadcast via over-the-air, satellite, and cable, or distributed digitally on streaming plat ...

s of many major sporting events for

instant replay Instant replay or action replay is a video reproduction of something that recently occurred, both shot and broadcast live TV, live. After being shown live, the video is replayed so viewers can see it again and analyze what just happened. Spo ...

s when normal slow motion is not slow enough, such as international

Cricket Cricket is a Bat-and-ball games, bat-and-ball game played between two Sports team, teams of eleven players on a cricket field, field, at the centre of which is a cricket pitch, pitch with a wicket at each end, each comprising two Bail (cr ...

matches.

Uses in science

High-speed cameras are frequently used in science in order to characterize events which happen too fast for traditional film speeds.

Biomechanics Biomechanics is the study of the structure, function and motion of the mechanical aspects of biological systems, at any level from whole organisms to Organ (anatomy), organs, Cell (biology), cells and cell organelles, using the methods of mechani ...

employs such cameras to capture high-speed animal movements, such as

jumping Jumping or leaping is a form of locomotion or movement in which an organism or non-living (e.g., robotic) mechanical system propels itself through the air along a ballistic trajectory. Jumping can be distinguished from running, galloping and ...

by frogs and insects,

suction feeding Aquatic feeding mechanisms face a special difficulty as compared to feeding on land, because the density of water is about the same as that of the prey, so the prey tends to be pushed away when the mouth is closed. This problem was first identifi ...

in fish, the strikes of

mantis shrimp Mantis shrimp are carnivorous marine crustaceans of the order Stomatopoda (). Stomatopods branched off from other members of the class Malacostraca around 400 million years ago, with more than 520 extant species of mantis shrimp known. All li ...

, and the aerodynamic study of pigeons' helicopter-like movements using

motion analysis Motion analysis is used in computer vision, image processing, high-speed photography and machine vision that studies methods and applications in which two or more consecutive images from an image sequences, e.g., produced by a video camera or high-s ...

of the resulting sequences from one or more cameras to characterize the motion in either 2-D or 3-D. The move from film to digital technology has greatly reduced the difficulty in use of these technologies with unpredictable behaviors, specifically via the use of continuous recording and post-triggering. With film high-speed cameras, an investigator must start the film then attempt to entice the animal to perform the behavior in the short time before the film runs out, resulting in many useless sequences where the animal behaves too late or not at all. In modern digital high-speed cameras, the camera can simply record continuously as the investigator attempts to elicit the behavior, following which a trigger button will stop the recording and allow the investigator to save a given time interval before and after the trigger (determined by frame rate, image size and memory capacity during continuous recording). Most software allows saving a subset of recorded frames, minimizing file size issues by eliminating useless frames before or after the sequence of interest. Such triggering can also be used to synchronize recording across multiple cameras. The explosion of alkali metals on contact with water has been studied using a high-speed camera. Frame-by-frame analysis of a sodium/potassium alloy exploding in water, combined with molecular dynamic simulations, suggested that the initial expansion may be the result of a

Coulomb explosion A Coulombic explosion is a condensed-matter physics process in which a molecule or crystal lattice is destroyed by the Coulombic repulsion between its constituent atoms. Coulombic explosions are a prominent technique in laser-based machining, ...

and not combustion of hydrogen gas as previously thought. Digital high-speed camera footage has strongly contributed to the understanding of

lightning Lightning is a natural phenomenon consisting of electrostatic discharges occurring through the atmosphere between two electrically charged regions. One or both regions are within the atmosphere, with the second region sometimes occurring on ...

when combined with

electric field An electric field (sometimes called E-field) is a field (physics), physical field that surrounds electrically charged particles such as electrons. In classical electromagnetism, the electric field of a single charge (or group of charges) descri ...

measuring instrumentation and sensors which can map the propagation of lightning leaders through the detection of

radio waves Radio waves (formerly called Hertzian waves) are a type of electromagnetic radiation with the lowest frequencies and the longest wavelengths in the electromagnetic spectrum, typically with frequencies below 300 gigahertz (GHz) and wavelengths ...

generated by this process.

Uses in industry

When moving from reactive maintenance to

predictive maintenance Predictive maintenance techniques are designed to help determine the condition of in-service equipment in order to estimate when maintenance should be performed. This approach claims more cost savings over routine or time-based preventive maint ...

, it is crucial that breakdowns are really understood. One of the basic analysis techniques is to use high-speed cameras in order to characterize events which happen too fast to see, e.g. during production. Similar to use in science, with a pre- or post-triggering capability the camera can simply record continuously as the mechanic waits for the breakdown to happen, following which a trigger signal (internal or external) will stop the recording and allow the investigator to save a given time interval prior to the trigger (determined by frame rate, image size, and memory capacity during continuous recording). Some software allows viewing the issues in real time, by displaying only a subset of recorded frames, minimizing file size and watch time issues by eliminating useless frames before or after the sequence of interest. High-speed video cameras are used to augment other industrial technologies such as x-ray radiography. When used with the proper phosphor screen which converts x-rays into visible light, high-speed cameras can be used to capture high-speed x-ray videos of events inside mechanical devices and biological specimens. The imaging speed is mainly limited by the phosphor screen decay rate and intensity gain which has a direct relationship on the camera's exposure. Pulsed x-ray sources limit frame rate and should be properly synchronized with camera frame captures.

Uses in warfare

In 1950 Morton Sultanoff, a physicist for the U.S. Army at Aberdeen Proving ground, invented a super high-speed camera that took frames at one-millionth of a second, and was fast enough to record the shock wave of a small explosion. High Speed digital cameras have been used to study how mines dropped from the air will deploy in near-shore regions, including development of various weapon systems. In 2005 high speed digital cameras with 4 megapixel resolution, recording at 1500 fps, were replacing the 35mm and 70mm high speed film cameras used on tracking mounts on test ranges that capture ballistic intercepts.

References