Underwater Fluorescence Photography

Author: admin at 14-05-2012, 23:05, Views: 4 953

Now available: a new frontier of underwater exploration and photography for night divers. Photographers can literally see the undersea world in a different light through the use of special­ized lights used at night to stimulate fluorescence photography (neon photography). Many have probably seen 'black light' posters at a party, or a display of fluorescent minerals at a museum. That's just what this is about - using a special light to bring out intense colors that can not be seen any other way. It may appear to be a trick, but it is an optical effect, just as real as what is seen during daylight or with an ordinary dive light. It is just DIFFERENT. Fluorescence can be seen in the daytime with no equipment at all. If you have seen corals or anemo­nes that appear orange or red at depths greater than about 30 feet or corals that were so green they appear to be glowing, you have seen fluorescence. Actually, the corals are absorbing blue and ultravio­let light from daylight and emitting it as different colors. However, the few corals and anemones that appear fluorescent during the day are more the exception than the rule. It is usually the ones that are the most 'normal' during the day, drab browns and grays giving absolutely no hint of fluorescence, that reveal the most spectacular displays with the right light at night. They are fluorescent in the daytime, but can not be seen in the bright daylight. After all, the full effect of a black light poster in a well-lit room is not possible, and the same is true underwater – fluorescence photography (neon photography) is best seen in the dark and harness with crotch strap assembly, and hip- mounted light canisters. These are just the very high points of a complete system that your GUE instructor will go over in detail during classes.

Whether you see yourself dabbling in nitrox to gaze a bit longer at those gorgeous reefs or emptying the line off an exploration reel miles underground, GUE can meet and exceed your goals. As Purdon says, "It is obvious that the passion for diving and the improvement of the dive training as a whole are the highest priority for everyone involved with the organization and it certainly 'rubs off' on their students." Inevitably, the letters on your c-card mean very little. It is the education received that makes all the difference. Remember that the goal of a diving career should not be having the largest c-card collection, but rather should be the pursuit of excellence in the aquatic arena. Jablonski says it best. "GUE was not formed to take over the diving industry. However, it is my hope that the dissemination of this information will assist individuals around the world, regardless of their agency affiliation." Choose your instructors wisely and settle for nothing less than the absolute best. There is no single best way to stimulate fluores­cence. What is seen depends upon how one views it. The 'Black lights' often used to light up posters at parties or exhibits in museums emit what is called long wave ultraviolet light, the light just beyond the blue end of the visible spectrum. Nevertheless, ultraviolet is not always the best way to produce fluorescence in the sea. Many or most, corals fluoresce better when hit with the right shade of blue than with ultraviolet. The blue fluorescence of shrimp, though, is brought out by ultraviolet but not blue. As for other critters, only time and more observation will tell. Night Sea offers a small dive light, the UltraBlue, especially designed for coral fluorescence, and the higher-power HID light, the Ultra Max, with intense ultraviolet output.

Fluorescence photography can reveal what otherwise would be difficult to see. A diver using the Night Sea Ultra Max in the Red Sea reports that he is easily finding some corals and other forms of underwater life that are well camou­flaged in normal light. Fluorescence can make very small critters show up clearly. Fluorescent corals and anemones as small as 1 mm (1/25 of an inch) against busy back­grounds from several feet away have been found. The key is that the fluorescent object glows, while the sur­roundings remain dark, making the objects easier to spot.
To take fluorescence photographs, as the ones illustrated in this article a filter is needed over the flash that restricts its output to just the wavelengths needed to stimulate fluorescence. Also needed is a filter in front of the camera lens to block the fluorescence-producing light from reaching the film. (Remember that the fluores­cence colors are different than the color of the light that brings them out). Film is normal color film, but depend­ing on the flash intensity and other factors, it may need to be high-speed film (ASA 400 or even faster). Very few people have taken fluorescence photographs underwa­ter, and its potential for artistic expression is almost completely untapped. Night Sea is offering the filter combinations to do either ultraviolet or blue-light fluorescence photography.

Besides opening up a beautiful new way of seeing the reef, looking for fluorescence photography is true exploration. The fluorescence of corals has been known (by a few) and written about (a little) for over forty years, but the little that has been documented was done in aquaria, with samples collected at random during the day. Very, very few divers have swum around at night with the right lights to stimulate fluorescence. A diver has an excellent chance of being the first person ever to fluorescence-dive a location and to see some never- described example of this magical effect. There is often confusion between fluorescence and bioluminescence. Just about everyone who night dives occasionally turns off their light, moves around, and sees glowing green sparks. In tropical waters divers have seen brilliant blue streaks of light and flashlight fish with red-glowing pouches under their eyes.

These are all examples of bioluminescence, not fluorescence. Various life forms in the sea, and of diverse types and sizes, have the internal chemistry to make their own light. For example, it is unnecessary to shine lights on fireflies to alight them. Most of the single-celled glowing species in the water only glow when a passing diver or fish disturbs them. Some, like flashlight fish, will simply light up or not in the presence of stimulus. However, corals and anemones do not light up by themselves, because they are not bioluminescent. Splashing water or blowing bubbles at them will not cause them to alight. Neverthe­less, many are fluorescent, glowing as the right light is pointed at them. Some alight brightly, others not; some alight in near pure intense colors, others in muted pastels. Sometimes the specie will alight all over its surface, sometimes it may alight only from polyp mouths or other identifiable body parts, or other isolated points on its surface.

Corals and anemones are the most prevalent sources of fluorescence on the reef, but they are not alone. Fish do not tend to be fluorescent, no matter how colorful they might appear in the daytime. Although, a small fish in the Bahamas with a pale blue glow under ultraviolet light has been discovered, and another diver reported that a small frog fish in the Red Sea had orange-pink fluorescent spots. Octopi we have looked at are colorful under normal white light but did not glow under the ultraviolet. Most shrimp fluoresce a distinct pale blue, and green nudibranchs, yellow tunicates, orange-red cowries, and bristle worms with glowing green heads and yellow fluorescent bars on their backs have been seen. source ; Guide to Underwater Fluorescence Photography

Dear visitor, you went to website as unregistered user.
We encourage you to Register or Login to website under your name.