Underwater photography is the process of taking photos while under water. This is usually done during scuba diving, but can be done while diving on the surface of supply, snorkeling, swimming, from submersible or remote underwater vehicles, or from automatic cameras lowered from the surface.
Underwater photography can also be categorized as an art form and method for recording data.
Successful underwater imaging is usually done with specialized equipment and techniques. However, it offers interesting and rare photographic opportunities. Animals such as fish and marine mammals are a common subject, but photographers also chase shipwrecks, submerged cave systems, underwater "landscapes, invertebrates, seagrasses, geological features, and fellow portraits.
Video Underwater photography
Exposure
The main obstacles faced by underwater photographers are the loss of color and contrast when submerged to significant depth. The longer the waves of sunlight (like red or orange) are absorbed rapidly by the surrounding water, so that even the naked eye is all blue-green. The color loss not only increases vertically through the water column, but also horizontally, so that the subject away from the camera also appears colorless and unclear. This effect occurs in clear water, as found around tropical reefs.
Underwater photographers solve this problem by combining two techniques. The first is to bring the camera closer to the subject of photography, minimizing the loss of horizontal color. Many serious underwater photographers consider more than about a yard or meter unacceptable. The second technique is the use of flash to restore lost color to depth. The flash content, effectively used, "paints" in the color lost by providing visible full spectrum light for overall exposure.
Another environmental effect is visibility. The water is rarely very clear, and the dissolved and suspended material can reduce visibility by absorption and light scattering.
Maps Underwater photography
Tools
Some cameras are made for underwater use, including modern waterproof digital cameras. The first amphibious camera was Calypso, reintroduced as Nikonos in 1963. The Nikonos range is specially designed for underwater use. Nikon ended the Nikonos series in 2001 and its use has declined, as has other 35mm film systems. Sea and Sea make Marine Motor III, a distance-amphibious seaplane camera for 35mm film.
Cameras made for dry work can also work under water, protected by an additional house, made for point and shoot cameras, compact cameras with full exposure controls, and single lens reflex cameras (SLRs). Most such houses are specific to cameras. Materials range from relatively inexpensive plastic to high quality aluminum. Housing allows a lot of options: the user can choose a home special for their daily "landline" camera and use any lens. Underwater photographers generally use a wide-angle lens or macro lens, both of which allow close focus and therefore a shorter distance to the subject, which reduces the loss of clarity to scattering. Digital media can store more shots than standard movies (which rarely have more than 36 frames per roll). This gives the digital camera an advantage, because it is not practical to turn the film under water. Another comparison between digital photography and film is also applicable, and the use of underwater films has declined, as it is on land.
The underwater house has buttons and control buttons that reach the inside of the camera, allowing the use of most of its normal functions. These houses may also have connectors to install an external flash unit. Some basic houses allow the use of flash on the camera, but on-board flash may not be strong enough or properly placed for underwater use. More advanced homes either direct the on-board strobe to a slave strobe fire through a fiber-optic cable, or physically prevent the use of an on-board strobe. Home made waterproof with silicone or other O-ring elastomers in crucial joints and where the control spindle and pushbutton pass through the housing. High-end homes can use double O-rings on many buttons and important spindles to reduce the risk of leakage, which can damage the electronics in the camera. Some waterproof cameras are inherently, or submersible to shallow depths; when it is in a house that can be accommodated, the consequences of a small leak are generally not serious.
There is an optical problem using a camera inside a waterproof housing. Due to refraction, images that enter through the glass port will be distorted, especially with wide-angle lenses. Dome-shaped port or fish eye corrects this distortion. Most manufacturers make this dome port for their home, often designing it for use with special lenses to maximize its effectiveness. The Nikonos series allows the use of water-contact optics designed for submerged use, without the ability to focus properly when used in the air. There are also problems with some digital cameras, which do not have a wide enough lens; To counter this, there is a home made with an additional optics beside the dome port, making the viewing angle look wider. Some homes work with wet-coupled lenses, which are screwed to the outside of the lens port and increase the field of view; These lenses can be added or removed underwater, allowing macro photography and wide-angle photography on the same dive.
With a macro lens, distortion caused by refraction is not a problem, so usually a simple flat glass port is used. Refraction increases macro lens enlargement; this is considered useful for photographers who try to capture a very small subject.
Underwater Flash
The use of flash or strobe is often considered the most difficult aspect of underwater photography. There are some misconceptions about the proper use of underwater flash, especially with regard to wide-angle photography. Generally, flash should be used to complete the overall exposure and return the lost color, not as the primary light source. In situations such as cave or shipwreck interiors, wide-angle images can be 100% strobe lights, but such situations are quite rare. Typically, photographers try to create an aesthetic balance between available sunlight and strobe. A deep, dark or low visibility environment can make this balance more difficult, but the concept remains the same. Many modern cameras have simplified this process through various modes of exposure and the use of luminous measurements (TTL). The increasing use of digital cameras has significantly reduced the underwater learning curve, as users can instantly review photos and make adjustments.
Color is absorbed as it flows through the water, so the deeper you are, the less red, orange, and yellow will remain. Strobo replaces that color. It also helps provide shadows and textures, and is a valuable tool for creativity.
The added complication is the backscatter phenomenon, in which the flash reflects the particles or plankton in the water. Even the clear-looking water contains many of these particles, even if not easily seen by the naked eye. The best technique to avoid backscatter is to position the strobe away from the camera lens axis. Ideally, this means the flash will not turn on the water directly in front of the lens, but it will still attack the subject. Various embedded arm and attachment systems are used to make lamps much easier to manipulate.
When using a macro lens, photographers are much more likely to use 100% spotlights for lighting. Subjects are usually very close to the lens, and available sunlight is usually not enough.
There have been several attempts to avoid using flash entirely, but this mostly fails. In shallow water, the use of custom white-balance provides excellent color without using strobe. In theory one can use color filters to cope with the blue-green shift, but this can be a problem. The number of shifts will vary with depth and turbidity, and there will still be significant contrast losses. Many digital cameras have settings that will provide color balance, but this can cause other problems. For example, images shifted to the "warm" part of the spectrum can create a background water that looks gray, purple or pink, and looks unnatural. There have been several successful experiments using filters combined with raw image format functionality on some high-end digital cameras, allowing more detailed manipulation in dark digital rooms. This approach will probably always be limited to shallow depths, where color loss is less extreme. Nevertheless, it can be effective for large subjects such as shipwreck that can not be lighted effectively with its lights.
Photography of natural light under water can be beautiful when done correctly with subjects like silhouette up, light beams, and large subjects such as whales and dolphins.
Although digital cameras have revolutionized many aspects of underwater imagery, it seems like flash can never be eliminated altogether. From an aesthetic standpoint, flash emphasizes the subject and helps separate it from the blue background, especially in the deeper waters. Ultimately the loss of color and contrast is a pervasive optical problem that can not always be customized in software like Photoshop.
Separate image
Another format considered as part of underwater photography is an over/under or split image, a composition that covers roughly half above the surface and half underwater, with both in focus. One of the pioneers of traditional engineering is the National Geographic photographer David Doubilet, who uses it to capture scenes above and below the surface simultaneously. Separate images are very popular in recreational scuba magazines, often showing divers swimming under a boat, or shallow coral reefs with shoreline visible in the background.
Over/under shots present some technical challenges beyond the scope of most underwater camera systems. Usually an ultra wide angle lens is used, similar to how it would be used in daily underwater photography. However, the exposure value in the water portion above the image is often higher (brighter) than under water. There is also a refractive problem in the underwater segment, and how it affects the overall focus in relation to the air segment. There is a separate, separate filter designed to compensate for both of these issues, as well as techniques to create a uniform exposure across the image.
However, pro photographers often use very wide lenses or fisheye lenses that provide extensive depth of field - and very small holes for greater depth of field; this is intended for a well-received sharp focus on nearby underwater subjects and elements further up on the water. An external flash can also be very useful under water, at low settings, to balance the light: to overcome the brightness differences of elements above and below water.
David Doubilet describes his technique for breaking the field of images in an interview for Nikon Corporation. "You need to use a D-SLR and a wide-angle superfine or fisheye lens and a sophisticated housing that has a dome instead of a flat port.The underwater image is enlarged by 25 percent, and the dome will correct for it.The technique requires a small f/16 or smaller - to a large depth of field, plus a lens capable of near focus, you always focus on the subject below the waterline.You also have to balance the light, looking for a lightweight bottom - white sand is best - or underwater subject I'll put the lights down and illuminate the bottom and then expose it to the top.If you shoot, say, ISO 400, you're going to have a lot of exposure for the top, and the lights will keep the bottom.Of course, You need a subject that suits this technique. "
Digital darkroom techniques can also be used to "combine" two images into one, creating a view of shooting above/below.
Skills and training
Since underwater photography is often done during scuba diving, it is important for photographer divers to be skilled enough to remain a safe enough activity. Good scuba techniques also improve image quality, since marine biota tend not to be scared by quiet divers, and the environment is less likely to be damaged or disturbed. There is the possibility of facing bad conditions, such as heavy currents, tidal flow, or poor visibility. Underwater photographers usually try to avoid this situation whenever possible. Underwater diving training providers provide courses to help improve diving skills and underwater photography skills.
Timeline
- 1856 - William Thompson takes the first underwater image using a camera mounted on a pole.
- 1893 - Louis Boutan takes underwater pictures in Banyuls-sur-Mer while diving using the surface provided by hard hat diving fixtures. He also developed an underwater flash and remote control for deep waters using an electromagnet.
- 1914 - John Ernest Williamson fired the first underwater film in the Bahamas.
- 1926 - William Harding Longley and Charles Martin took the first color color photo b/i using a magnesium-powered flash.
- 1940 - - Bruce Mozert starts photographing in Silver Springs, Florida
- 1957 - Camera CALYPSO-PHOT was designed by Jean de Wouters and promoted by Jacques-Yves Cousteau. It was first released in Australia in 1963. It has a maximum 1/1000 second shutter speed. A similar version was later produced by Nikon as Nikonos, with a shutter speed of 1/500 seconds and became the best-selling underwater camera series.
- 1961 - San Diego Underwater Photographic Society was founded, one of the earliest organizations dedicated to the advancement of underwater photography.
See also
- Diving tools
- List of basic photography topics
- Natural photography
- Underwater photography (sport)
- Underwater photography world championship
- Underwater videography
- Waterproof digital camera
References
External links
- Underwater photography on Curlie (based on DMOZ)
Source of the article : Wikipedia
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