Time Manipulation: High Speed Photography By Lauren Claire Pinches
Photography is defined as, “The process, activity and art of creating still or moving pictures by recording radiation on a sensitive medium, such as a photographic film or digital sensor.” (Wikipedia. 2010a). It is divided into many different sections and each of those requires unique skills and knowledge. This essay will be focusing on high speed photography by exploring the history, interesting photographic systems and the equipment needed for this specific type of photography.
As history proves, high speed photography is nearly in existence as long as photography itself. It is said that in 1893, H.W. Fox Talbot managed to capture the first image of Lacock Abbey with the exposure lasting several hours. Four years later, in 1843, Daguerre produced an exposure which only lasted a few minutes. This type of practical photography captured the attention of many interested communities. Then in 1981, Fox Talbot discovered that the light from an electric spark managed to freeze movement when capturing a photographic image. These series of events managed to transform the exposure time from several hours to that of a ten millionth of a second.
High speed photography is known as the science of taking photographs at an incredibly fast pace. Harold Edgerton is said to be the pioneer and master of high speed photography. Edgerton was born on April 6, 1903 in Fremont, Nebraska. He graduated in 1925 with an electrical engineering degree and decided to complete his graduate work at MIT (Massachusetts Institute of Technology), where he eventually joined the engineering faculty in 1932 as a professor. It has been said that Edgerton’s interest in high speed photography originated while he was busy with his Fig 1: Edgerton, H. 1957. Milk Drop Coronet.
doctoral research. In 1926, Edgerton developed the first flash tube that was able to emit high intensity bursts of light. From this development he has gained international recognition and has achieved many honors and awards for his contribution to photography. Edgerton’s discovery developed and transformed into the modern flash systems that we use today. 1
The first practical use of high speed photography was done by Eadweard Muybridge in 1878, when he chose to investigate whether all four of a horseâ€™s feet left the ground when galloping. The art of high speed motion pictures started in 1916 by German weapon scientists. Many different developments rose using stationary medium film in conjunction with a rotating mirror or a rotating prism. During this time Kodak shifted its film from Acetate to an Estar based product. This managed to increase the strength of the film and allowed it to be pulled faster through the rotating mechanisms. The rotary prism camera proved to place less strain on the film mechanisms which allowed the film to feed at a faster rate through the camera. The rotary mirror system is however able to capture 1,000,000 frames per second. More recently, the rotary mirror camera systems are able to capture 3,000,000 frames per second when used in conjunction with a CCD (charged-coupled device) sensor found in digital cameras.
The introduction of digital technology dramatically changed high speed photography. The CCD allowed precise control of the integration time, but it limited the rate at which the images could be read off the digital sensor. In development an image intensifier was added to the CCD, which made it possible for the digital camera to record 1,000,000 frames a second for 8-16 images. Recently photographic companies are in the process of developing cameras that can run at an excess of 2,000,000 frames per second.
High speed photography has become a new interactive research device and is used in many important operations around the world. The main objective of high speed photography is to capture a specific moment that one cannot see with the naked eye. High speed photography has provided researchers with an innovative way in which they can study physical movement, measure surface tension of objects, as well as the gravitational effects on the earth. It has also proven to assist the military with the testing of the accuracy of the missiles and rockets that they use. The use of high speed photography has also assisted photographers to a great degree when capturing fast pace sporting events such as NASCAR and horse racing. High speed photography has also been reproduced in many nature and wildlife magazines across all continents to show the world how animals move and live within their environment. 2
The success of high speed photography is completely dependent on how much light is entering the camera lens and the amount of time the film is being exposed to light. These factors can both be controlled by adjusting the shutter speed and aperture to suit the capturing system used in the photographic process. Another factor that one needs to take into account is the background used in the image. Lighting the background separately from the foreground has proved to be incredibly demanding, which is the reason why most high speed photographic images boast a completely black background. If necessary, photographers prefer to insert a coloured background in the post production stage of the image.
Strobe lights, as mentioned previously, were invented by Edgerton in 1926, but were only available to the public shortly after World War ll. The main feature of strobe lights is the ability to freeze movement by producing short flashes of high intensity light. It has been proved that the main studio flash lighting systems sync at a speed of 1/200 of a second, which is too slow when trying to capture high speed images. Strobes however, are able to operate between 0.5 and 1 millisecond or less. Working with elements that operate as fast, if not faster, as the moving object itself, will give the photographer the desired effect of a high speed photograph.
High Speed photography consists of two main photographic capturing systems. Using a flash system enables the photographer to capture crisp images within a studio environment. Placing the system within a fully dark room allows for the shutter to be placed on the â€œbulbâ€? setting, which will ultimately keep the shutter open for an extended amount of time. Capturing the image will be completely dependent on the use of high speed flash.
Using the fast shutter system allows the photographer to capture high speed photographic images in full daylight. A regular exposed image will have the shutter speed of about 1/125 of a second, but because one needs to capture high speed events the shutter speed needs to be adjusted to at least 1/8000 of a second. In doing this the photographer will have to compensate with a high ISO and a large aperture in order for the film or digital sensor to receive enough light. A high speed accessory shutter which gets attached to the front of a photographic lens is also available, which will accommodate for any camera delay normally experienced. 3
Three important factors that need to be taken into account when producing high speed photographic images are those of detection, synchronization and Imaging. When recording events that take place at a high speed, the objects have the ability to be completely unpredictable. Different triggers have been invented so that the picture itself can let the camera know when to photograph. They include sound, vibration, contact and light interrupted triggers. These then get connected to the flash unit when photographing in a controlled environment. The sound trigger is more commonly used as it is easy to make. A microphone, more commonly known as piezoelectric film, is a pressure sensitive material which has the ability to react to a noise such as a balloon popping. An amplifier and silicon are the other two main elements needed to make the sound trigger device. Triggers are used in conjunction with the flash system mentioned above, so the shutter can stay open when photographing in a dark room.
Synchronization in high speed photography is a very important factor. When shooting in daylight with a fast shutter system, the timing of ones shot is incredibly important. Capturing the object as it crosses the desired image plane poses as a challenge when dealing with camera delay time which is completely unavoidable. One needs to be aware of what causes the delay time in order to achieve complete synchronization, they are namely: the time needed for the sensor to respond and record the image, the delay when using an on camera flash and the mechanical components inside the camera more commonly known as the mirror and the shutter. Thankfully the measurement between the detection and synchronization stage can be calculated using a specific formula in order to have complete synchronization.
Imaging is the final factor of high speed photography and is done by light being painted onto the film or digital sensor to form an image. This follows the decision of which capturing system will be used namely: the flash system or the fast shutter system. One must remember to take into account many of the previously mention factors, such as the amount of light reaching the film or digital sensor, the ISO, shutter speed, aperture, the background and surroundings, as well as the light highlighting the object being photographed. Together all the elements of high speed photography will form a successful image. 4
In conclusion, high speed photography is not only used by professional photographers. With the right equipment and a positive attitude the desired effect can be obtained by anyone. Having a basic background on photography will help tremendously when dealing with high speed photography on a technical level. I envision that high speed photography is going to develop and with that make people aware of the important things in life.
Reference and Source List
Cooke, J. 2005. High Speed Photography. A Guide to Imaging, Rapid Movement and Transient Events. [Online] Retrieved on 21 August 2010 from: http://www.hidden-worlds.com/highspeed/text/welcome.htm
Fuller, J. 2008. How High Speed Photography Works. [Online] Retrieved on 21 August 2010 from: http://electronics.howstuffworks.com/high-speedphotography.htm/
McGraw. 2005. Photography. Hill Encyclopedia of Science and Technology. [Online] Retrieved on 20 August 2010 from: http://www.answers.com/topic/photography
Wikipedia. 2010a. Photography. [Online] Retrieved on 20 August 2010 from : http://en.wikipedia.org/wiki/Photography .
Wikipedia. 2010b. High Speed Photography. [Online] Retrieved on 19 August 2010 from: http://en.wikipedia.org/wiki/high_speed_photography
Figure Reference List
Edgerton, H. 1957. Milk Drop Coronet. [Online] Retrieved on 21 August 2010 from: http://www.vam.ac.uk/vastatic/microsites/photography/magnify.php?im ageid=im00231