Underwater videography
Encyclopedia
Underwater videography is a video production
, the branch of underwater photography
concerned with capturing underwater
moving images either as a recreational diving
or commercial documentary
, or filmmaking
activity.
ing the camera from water at high pressure
, while maintaining the ability to operate it< The diving mask
also inhibits the ability to view the camera image and to see the monitoring screen clearly through the camera housing. Previously the size of the video camera
was also a limiting factor, necessitating large housings to enclose the separate camera and record deck. This results in a larger volume which creates extra buoyancy
requiring a corresponding use of heavy weight to keep the housing underwater (about 64 lbs. per cubic foot of displacement or 1 kilogram
per litre
in the ocean). Early video cameras also needed large batteries because of the high power
consumption of the system.
A final problem is the lower level of light
underwater. Early cameras had problems with low light levels, were grainy, and did not see much color underwater without auxiliary lighting. Large unwieldy lighting systems were problematic to early underwater videography. And last, underwater objects viewed from an airspace, such as the eye inside a mask or the camera inside a housing, appear to be about 25% larger than they are. The photographer needs to move farther back to get the subject into the field of view. Unfortunately that puts more water between the lens and the subject resulting in less clarity and reduced color and light.
s with large view screens and long-life rechargeable batteries has reduced the housing size and made underwater videography
an easy, fun activity for the diver. Low-cost wide-angle lens
add-ons are available for many cameras and some can even be fitted outside the camera housing for versatile use. This lets the photographer get closer and make the subject clearer and also with fewer focus
ing and depth of field
problems. Today cameras are more sensitive to low light conditions and make automatic color balancing adjustments. Nevertheless, deeper water videography still needs auxiliary light sources to bring out colors filtered out of sunlight
by the distance it has travelled through water. The longest wavelengths of light
are lost first (reds
and yellow
s) leaving only a green
ish or blue
cast in deep water. Even a hand light will help show off some of the magnificent colors of a coral reef
or other marine life if used during recording.
seal, and through housings fittings for several camera controls. A few are generic in nature from several manufacturers (such as Ikelite), and may be adaptable to several camera sizes. Most housings, however, are specific to the size and controls of a particular camera type and may be marketed by the camera manufacturer or an after-market company.
Occasionally housings might be advertised as "water housings" rather than underwater housings. Water housings are not intended for deepwater use, but rather are "splash housings for use around the pool, in rain, or to protect against falling overboard. At the most they are for very shallow activities - usually not more than about 1 or 2 metres / 3 to 6 feet in depth. One particular manufacturer offers a plastic bag type solution with a watertight seal, and a glass port front. The flexible bag allows some modest camera control, but suffers greatly when taken deeper since the bag compresses from the pressure and makes controls nearly impossible to operate. These are usually limited to snorkeling activities.
techniques. Names you might recognize are Quicktime
Video or Real Video, .WMV, or.AVI
files. These file formats are usually limited in display screen resolution (measured by pixel
height by width) and are not intended to be played on anything larger than a computer screen. Recording options are limited and quality is usually at the low end (for example 640x480 screen size or even smaller). Capacity is often limited by the SD card or CompactFlash card in the camera.
A dedicated video camera, on the other hand may also have a "still frame" or snapshot capability. This is a better choice if the first intent is to have high quality moving pictures and an occasional still picture. Camera capacity, based on videotape
s, or even harddrive recording is usually at least 2 hours, and necessitates very little opening of the housing during the dive day. Check the Pixel quality (4 megapixels or above preferred) on the video camera capability if this is of interest. For the best results, Hi-definition video cameras have recently arrived (1080i
) which, like high definition television screens, will provide the best of quality and image resolution.
The trend today is toward replaceable memory cards for recording, or internal hard-drives built into the camera. This provides maximum versatility, high recording time options, and few mechanical breakdown possibilities, not to mention minimizing problems with condensation affecting the recording (tape) media of previous generations. The subsequent files may be easily transferred to a computer and edited with low-cost software solutions (and a reasonably high performance computer and video card). The subsequent results may be transferred to a CD or DVD (and more recently Blu-ray Disc
) for easy distribution or archiving.
is noted as one of the first films to use underwater cinematography
to show the ocean depths in color
. Its title derives from Jacques-Yves Cousteau
's 1953 book The Silent World: A Story of Undersea Discovery and Adventure
.
Video production
Video production is videography, the process of capturing moving images on electronic media even streaming media. The term includes methods of production and post-production...
, the branch of underwater photography
Underwater photography
Underwater photography is the process of taking photographs while under water. It is usually done while scuba diving, but can be done while snorkeling or swimming.-Overview:...
concerned with capturing underwater
Underwater
Underwater is a term describing the realm below the surface of water where the water exists in a natural feature such as an ocean, sea, lake, pond, or river. Three quarters of the planet Earth is covered by water...
moving images either as a recreational diving
Recreational diving
Recreational diving or sport diving is a type of diving that uses SCUBA equipment for the purpose of leisure and enjoyment. In some diving circles, the term "recreational diving" is used in contradistinction to "technical diving", a more demanding aspect of the sport which requires greater levels...
or commercial documentary
Documentary film
Documentary films constitute a broad category of nonfictional motion pictures intended to document some aspect of reality, primarily for the purposes of instruction or maintaining a historical record...
, or filmmaking
Filmmaking
Filmmaking is the process of making a film, from an initial story, idea, or commission, through scriptwriting, casting, shooting, directing, editing, and screening the finished product before an audience that may result in a theatrical release or television program...
activity.
Limitations
The primary difficulty in underwater camera usage is, of course, sealSeal (mechanical)
A mechanical seal is a device which helps join systems or mechanisms together by preventing leakage , containing pressure, or excluding contamination...
ing the camera from water at high pressure
Pressure
Pressure is the force per unit area applied in a direction perpendicular to the surface of an object. Gauge pressure is the pressure relative to the local atmospheric or ambient pressure.- Definition :...
, while maintaining the ability to operate it< The diving mask
Diving mask
A diving mask is an item of diving equipment that allows scuba divers, free-divers, and snorkelers to see clearly underwater. When the human eye is in direct contact with water as opposed to air, its normal environment, light entering the eye is refracted by a different angle and the eye is unable...
also inhibits the ability to view the camera image and to see the monitoring screen clearly through the camera housing. Previously the size of the video camera
Video camera
A video camera is a camera used for electronic motion picture acquisition, initially developed by the television industry but now common in other applications as well. The earliest video cameras were those of John Logie Baird, based on the electromechanical Nipkow disk and used by the BBC in...
was also a limiting factor, necessitating large housings to enclose the separate camera and record deck. This results in a larger volume which creates extra buoyancy
Buoyancy
In physics, buoyancy is a force exerted by a fluid that opposes an object's weight. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus a column of fluid, or an object submerged in the fluid, experiences greater pressure at the bottom of the...
requiring a corresponding use of heavy weight to keep the housing underwater (about 64 lbs. per cubic foot of displacement or 1 kilogram
Kilogram
The kilogram or kilogramme , also known as the kilo, is the base unit of mass in the International System of Units and is defined as being equal to the mass of the International Prototype Kilogram , which is almost exactly equal to the mass of one liter of water...
per litre
Litre
pic|200px|right|thumb|One litre is equivalent to this cubeEach side is 10 cm1 litre water = 1 kilogram water The litre is a metric system unit of volume equal to 1 cubic decimetre , to 1,000 cubic centimetres , and to 1/1,000 cubic metre...
in the ocean). Early video cameras also needed large batteries because of the high power
Electric power
Electric power is the rate at which electric energy is transferred by an electric circuit. The SI unit of power is the watt.-Circuits:Electric power, like mechanical power, is represented by the letter P in electrical equations...
consumption of the system.
A final problem is the lower level of light
Light
Light or visible light is electromagnetic radiation that is visible to the human eye, and is responsible for the sense of sight. Visible light has wavelength in a range from about 380 nanometres to about 740 nm, with a frequency range of about 405 THz to 790 THz...
underwater. Early cameras had problems with low light levels, were grainy, and did not see much color underwater without auxiliary lighting. Large unwieldy lighting systems were problematic to early underwater videography. And last, underwater objects viewed from an airspace, such as the eye inside a mask or the camera inside a housing, appear to be about 25% larger than they are. The photographer needs to move farther back to get the subject into the field of view. Unfortunately that puts more water between the lens and the subject resulting in less clarity and reduced color and light.
Modern improvements
Today, the small size of fully automatic camcorderCamcorder
A camcorder is an electronic device that combines a video camera and a video recorder into one unit. Equipment manufacturers do not seem to have strict guidelines for the term usage...
s with large view screens and long-life rechargeable batteries has reduced the housing size and made underwater videography
Videography
Videography refers to the process of capturing moving images on electronic media even streaming media). The term includes methods of video production and post-production...
an easy, fun activity for the diver. Low-cost wide-angle lens
Wide-angle lens
From a design perspective, a wide angle lens is one that projects a substantially larger image circle than would be typical for a standard design lens of the same focal length; this enables either large tilt & shift movements with a view camera, or lenses with wide fields of view.More informally,...
add-ons are available for many cameras and some can even be fitted outside the camera housing for versatile use. This lets the photographer get closer and make the subject clearer and also with fewer focus
Focus (optics)
In geometrical optics, a focus, also called an image point, is the point where light rays originating from a point on the object converge. Although the focus is conceptually a point, physically the focus has a spatial extent, called the blur circle. This non-ideal focusing may be caused by...
ing and depth of field
Depth of field
In optics, particularly as it relates to film and photography, depth of field is the distance between the nearest and farthest objects in a scene that appear acceptably sharp in an image...
problems. Today cameras are more sensitive to low light conditions and make automatic color balancing adjustments. Nevertheless, deeper water videography still needs auxiliary light sources to bring out colors filtered out of sunlight
Sunlight
Sunlight, in the broad sense, is the total frequency spectrum of electromagnetic radiation given off by the Sun. On Earth, sunlight is filtered through the Earth's atmosphere, and solar radiation is obvious as daylight when the Sun is above the horizon.When the direct solar radiation is not blocked...
by the distance it has travelled through water. The longest wavelengths of light
Visible spectrum
The visible spectrum is the portion of the electromagnetic spectrum that is visible to the human eye. Electromagnetic radiation in this range of wavelengths is called visible light or simply light. A typical human eye will respond to wavelengths from about 390 to 750 nm. In terms of...
are lost first (reds
Reds
Reds is a 1981 American epic film that was co-written, produced, directed by and starred Warren Beatty. It centers on the life and career of John Reed, the revolutionary communist, journalist, and writer who chronicled the Russian Revolution in his book Ten Days that Shook the World...
and yellow
Yellow
Yellow is the color evoked by light that stimulates both the L and M cone cells of the retina about equally, with no significant stimulation of the S cone cells. Light with a wavelength of 570–590 nm is yellow, as is light with a suitable mixture of red and green...
s) leaving only a green
Green
Green is a color, the perception of which is evoked by light having a spectrum dominated by energy with a wavelength of roughly 520–570 nanometres. In the subtractive color system, it is not a primary color, but is created out of a mixture of yellow and blue, or yellow and cyan; it is considered...
ish or blue
Blue
Blue is a colour, the perception of which is evoked by light having a spectrum dominated by energy with a wavelength of roughly 440–490 nm. It is considered one of the additive primary colours. On the HSV Colour Wheel, the complement of blue is yellow; that is, a colour corresponding to an equal...
cast in deep water. Even a hand light will help show off some of the magnificent colors of a coral reef
Coral reef
Coral reefs are underwater structures made from calcium carbonate secreted by corals. Coral reefs are colonies of tiny living animals found in marine waters that contain few nutrients. Most coral reefs are built from stony corals, which in turn consist of polyps that cluster in groups. The polyps...
or other marine life if used during recording.
Video housings
Most modern underwater housing are pressure resistant to about one hundred feet, the practical safe depth of sport-diving. Typical construction is from moulded polycarbonate plastic, or aluminium for more professional systems. They usually have quick release snaps, an o-ringO-ring
An O-ring, also known as a packing, or a toric joint, is a mechanical gasket in the shape of a torus; it is a loop of elastomer with a disc-shaped cross-section, designed to be seated in a groove and compressed during assembly between two or more parts, creating a seal at the interface.The O-ring...
seal, and through housings fittings for several camera controls. A few are generic in nature from several manufacturers (such as Ikelite), and may be adaptable to several camera sizes. Most housings, however, are specific to the size and controls of a particular camera type and may be marketed by the camera manufacturer or an after-market company.
Occasionally housings might be advertised as "water housings" rather than underwater housings. Water housings are not intended for deepwater use, but rather are "splash housings for use around the pool, in rain, or to protect against falling overboard. At the most they are for very shallow activities - usually not more than about 1 or 2 metres / 3 to 6 feet in depth. One particular manufacturer offers a plastic bag type solution with a watertight seal, and a glass port front. The flexible bag allows some modest camera control, but suffers greatly when taken deeper since the bag compresses from the pressure and makes controls nearly impossible to operate. These are usually limited to snorkeling activities.
Still/video combinations
Most current digital still cameras are also capable of what is sometimes referred to as "Internet Video". This is usually a variation of the MPEG video standard of digital imaging created as a streaming series of digital images, with some advanced compressionData compression
In computer science and information theory, data compression, source coding or bit-rate reduction is the process of encoding information using fewer bits than the original representation would use....
techniques. Names you might recognize are Quicktime
QuickTime
QuickTime is an extensible proprietary multimedia framework developed by Apple Inc., capable of handling various formats of digital video, picture, sound, panoramic images, and interactivity. The classic version of QuickTime is available for Windows XP and later, as well as Mac OS X Leopard and...
Video or Real Video, .WMV, or.AVI
Audio Video Interleave
Audio Video Interleave , known by its acronym AVI, is a multimedia container format introduced by Microsoft in November 1992 as part of its Video for Windows technology. AVI files can contain both audio and video data in a file container that allows synchronous audio-with-video playback...
files. These file formats are usually limited in display screen resolution (measured by pixel
Pixel
In digital imaging, a pixel, or pel, is a single point in a raster image, or the smallest addressable screen element in a display device; it is the smallest unit of picture that can be represented or controlled....
height by width) and are not intended to be played on anything larger than a computer screen. Recording options are limited and quality is usually at the low end (for example 640x480 screen size or even smaller). Capacity is often limited by the SD card or CompactFlash card in the camera.
A dedicated video camera, on the other hand may also have a "still frame" or snapshot capability. This is a better choice if the first intent is to have high quality moving pictures and an occasional still picture. Camera capacity, based on videotape
Videotape
A videotape is a recording of images and sounds on to magnetic tape as opposed to film stock or random access digital media. Videotapes are also used for storing scientific or medical data, such as the data produced by an electrocardiogram...
s, or even harddrive recording is usually at least 2 hours, and necessitates very little opening of the housing during the dive day. Check the Pixel quality (4 megapixels or above preferred) on the video camera capability if this is of interest. For the best results, Hi-definition video cameras have recently arrived (1080i
1080i
1080i is the shorthand name for a high-definition television mode. The i means interlaced video; 1080i differs from 1080p, in which the p stands for progressive scan. The term 1080i assumes a widescreen aspect ratio of 16:9, implying a frame size of 1920×1080 pixels...
) which, like high definition television screens, will provide the best of quality and image resolution.
The trend today is toward replaceable memory cards for recording, or internal hard-drives built into the camera. This provides maximum versatility, high recording time options, and few mechanical breakdown possibilities, not to mention minimizing problems with condensation affecting the recording (tape) media of previous generations. The subsequent files may be easily transferred to a computer and edited with low-cost software solutions (and a reasonably high performance computer and video card). The subsequent results may be transferred to a CD or DVD (and more recently Blu-ray Disc
Blu-ray Disc
Blu-ray Disc is an optical disc storage medium designed to supersede the DVD format. The plastic disc is 120 mm in diameter and 1.2 mm thick, the same size as DVDs and CDs. Blu-ray Discs contain 25 GB per layer, with dual layer discs being the norm for feature-length video discs...
) for easy distribution or archiving.
History
Sesto Continente directed by Folco Quilici and released in 1954, was the first full-length, full-color underwater documentary. The Silent WorldThe Silent World
The Silent World is a 1956 French documentary film co-directed by the famed French oceanographer Jacques-Yves Cousteau and a young Louis Malle. The Silent World is noted as one of the first films to use underwater cinematography to show the ocean depths in color...
is noted as one of the first films to use underwater cinematography
Underwater photography
Underwater photography is the process of taking photographs while under water. It is usually done while scuba diving, but can be done while snorkeling or swimming.-Overview:...
to show the ocean depths in color
Color photography
Color photography is photography that uses media capable of representing colors, which are traditionally produced chemically during the photographic processing phase...
. Its title derives from Jacques-Yves Cousteau
Jacques-Yves Cousteau
Jacques-Yves Cousteau was a French naval officer, explorer, ecologist, filmmaker, innovator, scientist, photographer, author and researcher who studied the sea and all forms of life in water...
's 1953 book The Silent World: A Story of Undersea Discovery and Adventure
The Silent World: A Story of Undersea Discovery and Adventure
The Silent World is a 1953 book co-authored by Captain Jacques-Yves Cousteau and Frédéric Dumas and edited by James Dugan. Although a French national, Cousteau wrote the book in English...
.