Archive for January, 2006

The skin or scuba diver who is contemplating underwater photography must consider the effect of his photographic equipment on his underwater mobility. The weight of sea water is about 800 times that of air. While the diver with any experience has adapted himself to this medium, he may not realize the extra “drag” of his camera against the water. Even a fairly small camera housing with a flat surface will slow down his underwater progress considerably. In fact, many professional and semiprofessional underwater photographers use power packs to compensate for the drag of their photographic equipment. At any considerable depth the extra exertion required to move the camera through water may exceed the amount of air that can be provided by the aqualung or other breathing device. A smaller streamlined camera housing may be considered in place of a larger rectangular model. Another inherent hazard is found in the plastic bag-type housings which may “explode” if carried down too deep.

Some earlier camera housings were provided with neck straps to allow the diver-photographer freer use of his hands, but it was found that this was potentially dangerous, as the straps could interfere with the hoses, and even the pressure of the case against the diver could be hazardous. The safest types are those with a set of handles and slight negative buoyancy. For adequate safety, the camera housing should have a working pressure of about 100 pounds per square inch and a test pressure of 200 to 300 per square inch.

All equipment used under water should be free from any sharp projections or corners that could cut the diver or tear his suit. The knobs and levers on the camera housing should be large enough to be manipulated under water, and so designed that they cannot snag the diver’s underwater gear or cut him.

An underwater writing slate is a handy accessory to make a notation as each picture is taken, to obtain an idea of the limitations and best operating situations for the camera being used. In scuba diving with camera, one of the greatest risks is becoming so involved with picture taking that you lose track of the time spent under water. Adherence to the diving tables is vital, and keep in mind the additional burden of the camera.

Professional water skiing is a very exciting, fun sport, however it takes lots of practice and hard work.  Professional water skiing is one of the most popular water sports in the world.  The exciting jumps and tricks make this game so entertaining to everyone.
 
If you are a professional water skier, then you know how hard you have to work.

Professionals practice long hard hours and fail many times before finally succeeding.  To be good at water skiing, you have to have balance and strong arms and legs.  If you did not have these things before, you can be sure to have them once you have practiced for a while. 

Water skiing is a thrilling ride through the water and over waves.  Professional skiers do the jumps and tricks that make the sport even more exciting.  Being a professional means not only being able to perform the jumps and turns, but also means they have great communication with the driver of the boat. 

Aside from the other conditions which affect underwater photography, the fact that air is about 1,000 times as transparent as water creates a condition which makes it impossible to use standard focus lenses or telephoto lenses in underwater photography. To obtain contrast, the photographer must, as we have noted, get as close to the subject as possible. Also, while in surface photography it is possible to set the range for the distance from the lens to the subject, this becomes almost impossible under water. In almost all underwater picture taking, both the photographer and the subject are in motion, in three dimensions in a fluid medium. For this reason, the depth of field should be great enough to compensate for the inability to pinpoint the shooting distance with any accuracy. In surface photography such a condition could be corrected to some extent by reducing the diaphragm opening, but underwater photography needs every bit of light available, whether natural or artificial light is used. Therefore it is essential that the shortest possible focal length lens be used.

In addition, the wider the angle of field, the better the photograph taken under water. Unless the subject is framed against the ocean bottom, coral, or some other underwater object, the resulting picture will lack the frame of reference that makes a good underwater shot.

Many camera housings for underwater photography use a flat window or porthole through which the photograph is taken. This flat surface in front of the lens may cause some distortion outside the central portion of the photograph. This can be corrected by the use of a submarine lens attachment which is mounted into the front of the housing, replacing the flat window. This housing consists of two elements 3 or 4 centimeters apart, with the front surface in contact with the water. This correction lens permits focusing for the real distance of the subject without correction, and considerably increases the depth of field.

For lens use underwater there are two vital considerations and they are of equal importance: the power of the lens and its greatest aperture. About the minimum lens quality for underwater use is 1:3.5 for black and white or color.

The 35 mm still cameras are the most popular for underwater use, and the lenses that have proved most effective with them are 30 mm maximum for 24 x 24 mm and not more than 35 mm wide-angle lenses for 24 x 36 mm. For use in 16 mm motion-picture cameras, wide-angle lenses 12.5 to 9 mm focal length have worked out best.

The sport has since progressed to free skiing with the rope held by the skier in his hand, in the early years, the boats were not designed to cater to the skier s requirements.  In the fifties and upwards is when the introduction of the new well designed equipment came to be known.

These introductions in conjunction with less expensive and more powerful boats have made water-skiing a more popular sport. 

Water skiing has taken off in those Countries that enjoy warmer sun and water. In countries with less favorable weather conditions and colder water, the progress has been a little slower. 

With intensive and consistent training, and along with a wet suit, anyone anywhere can become a skilled water skier. 

This sport is an ideal activity for families because everyone can participate.  Not everyone will develop the skill and interest in the sport, but the members left on the boat will have just as much fun watching their loved one ride the waves. 

One of the first problems of underwater photography that the novice may discover is that standard view-finders are of little use under water. Specially made underwater cameras are invariably equipped with a frame or gunsight-type view-finder. With a camera encased in its underwater housing, it is almost impossible for a photographer to get his eye close enough to the conventional finder to fix the image he wants to capture. Since he will usually be wearing a mask or goggles, his eye will be removed another inch to three inches from the finder.

Reflex-type view-finders might seem to offer a solution, but they create additional complications. An additional pressure-protected opening in a metal housing would be required to observe the focusing screen or ground glass, and there is the possibility of some distortion through the sides of a water-surrounded plexiglass housing. In addition, there is the problem of clouding up through condensation. The old reliable spit, or soap, can be rubbed on the windows to cut down this clouding. There are also some chemical compounds on the market which may be put into the housing to absorb the moisture, but some of them may dry up the film and make it brittle if it is left in the loaded camera too long.

Generally, the most effective view-finders for underwater

use are the frame-finders similar to those used on press or “sports” cameras, and the smaller gunsight-finders. The frame-finder on the underwater housing must necessarily be of strong construction for underwater usage. With the use of a wide-angle lens, it will often be found that the scope of the lens is somewhat wider than the field of the finder. In using the underwater frame or gunsight viewfinder, the sight nearest the eye is centered on the frame through visual alignment. Since the time for setting a camera underwater is limited, many underwater photographers preset their cameras for two fixed ranges-3 feet or so for close-ups, and about 10 feet for longer shooting.

Water skiing has been around for a lot longer than many think.  The history of water skiing goes back to 1922 when Ralph Samuelson of Lake City, Minnesota.  He is the first person known to ever water ski. 

He mastered the skies, went on to build a ramp, and became the first known water ski jumper.  He was always looking for new things to accomplish with the water skies.  In later years, he skied beyond a flying boat.  This was before he knew any better.

By 1946, there was a lot of progress in the sport, so much that there was a pressing need for a controlling body to coordinate skiing activities throughout the world and to make up rules and regulations. 

This lead to the World Water Ski Union being formed in 1946.  This made it possible for the first World War Ski Championships being held in 1949 at Juan-les-Pins. 

Underwater Film

The old adage about “walking before you try to run” certainly applies to underwater photography. It might be best for the beginner in this activity to start off with black-and-white work in rather shallow water with natural lighting before attempting deeper picture-taking dives or work with color film or flash gun. Any slow panchromatic black-and-white film should provide prints with good color contrast. For color work, the Eastman Kodak Company makes the following suggestions, which apply equally to comparable film under other trade names:

The use of Kodacolor film has several advantages for underwater color shooting. It has greater exposure latitude than reversal films, such as Kodachrome film or Kodak Ektachrome film. This latitude helps minimize any exposure errors that might be made under the uncertain lighting conditions found under water. Another advantage is that no filters need be used on the camera for correcting the color balance of the film for underwater shooting. Such corrections can be made when a print or transparency is made from the color negative. Kodacolor film is available in sizes to fit almost any camera.

APPROXIMATE EXPOSURES FOR UNDERWATER PHOTOGRAPHY Assuming bright sunlight and light bottom. A dark bottom may require one or two more lens openings; even so, it may cause poorly lighted subjects. Hazy sunlight will usually require at least one-half a lens opening larger.

Color Shots

Except in very clear water, the light that does penetrate is generally strongly scattered, so that it produces a colored haze or cloudiness between the camera and the subject. Therefore, in order to reduce the effects of intervening haze, it is usually desirable to work as close to the subject as possible. This is especially true in color photography, because the color of the haze quickly overcomes other subject colors.

The color of the water varies from one location to another. In fact, even in one location it can change from day to day or even hour to hour as a result of suspended particles of rock or soil and the kind and amount of minute suspended plants and animals. In certain circumstances the over-all tint imparted by the color of the water can be offset to some extent by the use of color-compensating filters. It is usually not possible to make colors reproduce as they would if the subject were above water, but such an effect is not usually desired, anyway.

Artificial Light

The use of underwater flash should be very helpful, not only because it will, more or less independent of depth, supply more dependable illumination than natural light, but also because it will probably give less trouble from the colored scatter haze. Exposure settings for flash shots will depend on the particular equipment used and is best determined by practical experience. The use of artificial lighting is also important because some of the more tempting underwater scenes will often be in darker spots in caves, wrecks and similar locations.

Another reason for the use of flash equipment is that the water at some depth is likely to be less turbid than shallow water, providing a better photographic medium but requiring some source of light for effective photography.

However, there are some limitations on the use of ordinary flash bulbs under water. Since sea water transmits only blue and green, it will tend to damp out the light from a magnesium bulb, which is rich in red and somewhat poor in blue colors. Another problem in underwater photography is the need to rise to the surface to change bulbs after each flash. Both of these problems may be counteracted by the acquisition of a somewhat more expensive electronic flash bulb of the stroboscopic type, which will allow repeated picture taking with no bulb changes. It is also better adapted for rapid action shots without the blurring caused by motion of the subject.

Focal Length

Because of the refraction of light as it passes through water, underwater “feet” are only 9 inches long. This means that a lense of normal focal length will produce a slight telephoto effect when used under water. For this reason it is desirable to use a wide-angle lens if possible. Such a lens has greater depth of field, which is useful when shooting under water where it may be hard to adjust the focus with simple “bag-type” camera enclosures. Some special underwater cameras have focus settings calibrated for underwater distance.