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.
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, of course, 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 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.
Today, the small size of fully automatic camcorders 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 focusing 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 yellows) leaving only a greenish 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.
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-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.
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 compression techniques. Names you might recognize are QuickTime Video or RealVideo, .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 videotapes, 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.
- Hans-Hass-Institut für Submarine Forschung und Tauchtechnik. "Die Filme von Prof. Dr. Hans Hass".
- "Sesto Continente (1954); Alternate Title: Sixth Continent". The New York Times. Retrieved 2009-03-24.
- "Sesto continente (1954)". IMDb.com, Inc. Retrieved 2009-03-24.
- Kagan, Becky (16 May 2009). "Task Loading Tips For Underwater Photographers & Videographers". DivePhotoGuide.com. Retrieved 2009-06-03.