Underwater videography

Underwater videography is the branch of electronic underwater photography concerned with capturing underwater moving images as a recreational diving, scientific, commercial, documentary, or filmmaking activity.

In 1940 Hans Hass completed Pirsch unter Wasser (i.e. Stalking under Water) which was published by the Universum Film AG, lasted originally only 16 minutes and was shown in theatres before the main movie, but would eventually be extended by additional filming done in the Adriatic Sea close to Dubrovnik. It premiered in Berlin in 1942.

Sesto Continente directed by Folco Quilici and released in 1954, was the first full-length, full-color underwater documentary.The Silent World 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.

The primary difficulty in underwater camera usage is sealing 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 1.03 kilogram per litre in sea water or 63 lbs per cubic foot of displacement (1 kilogram per litre) in fresh water). Early video cameras also needed large batteries because of the high power consumption of the system. Current Lithium-ion batteries have long run times with relatively light weight and low volume.

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