The Universe Below: Creating Underwater Allskies
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The Universe Below: Creating Underwater Allskies Tom Kwasnitschka and Wilhelm Ermgassen Hertzstr. 35 24149 Kiel Germany kwasnitschka{at}@allsky.de www.allsky.de It has become fashionable to broaden the Luckily we are also sports divers, and one appropriate Sea&Sea housing and dome port. thematic spectrum of planetarium shows. of us holds a scientific divers’ certificate. We The dome port is the spherical glass window Our visitors no longer gain insight into the already had some general knowledge of in front of the lens which corrects the wonders of just the night sky. They can also underwater photography as well as the right decrease in the field of view that a flat win- enjoy laser-enhanced music shows or pro- diving skills. dow would produce underwater. Next we grams on general natural science at wanted to address technical issues. On the planetarium of their choice. As Long experience in the field of allsky land we usually take six photographs planetarium operators, we have to still photography led the team of all- using a QTVR-head that prevents par- incorporate new media and imagery sky.de to create a thematic program of allax and provides an even angle of to address these topics. underwater allskies. The experiences 60° between the images. We needed So it was natural to us at allsky.de to an underwater equivalent that was include non-astronomical allskies as a and techniques they developed are not extremely sturdy, absolutely non-cor- vital part of our range of products. just a curiosity among divers, but may rosive at contact with seawater and, This year we decided to run a whole serve as an encouragement to design- above all, easy to handle. To enable assignment for the first time entirely parallax correction, we simplified the on one topic. We travelled to Egypt to ers of progressive planetarium shows. design to two perpendicular metal produce material on antique astrono- rods that could be attached to each my. Starting at the Giza Pyramids, we photo- We began to dream: Hovering in the other at any point using a single screw. graphed our path up the Nile to Luxor, the water, one can capture scenes that would Another screw fixed the camera to the verti- Valley of Kings, and Abu Simbel. During the normally ask for a Hollywood elevator or a cal rod. The construction was then screwed preparations for the trip it occurred to us high ladder at least. Yet in any case one needs onto a fixable swivel joint that exactly that we could really cover another fascinat- a fixed point in the water column to control copied the design we already used. Having ing world untapped by allsky photography: the orientation of the camera. accomplished this, we lost our enthusiasm the reefs of the Red Sea. In our functions as The question arose whether we should use for welding and turning and decided to use a show producers at the Kiel Planetarium we a tripod as on land, or suspend a buoy at the spare sturdy tripod by Manfrotto as a had long wanted to have some allskies of position and depth we wanted to take a mounting. coral, wrecks, or just waves from beneath. photo and hold the camera at a point in ref- In complete negligence of traditional un- Yet all the material we knew of was either erence to it. In the end we decided to com- derwater photography we decided to use no computer-rendered, made up of several unre- pletely transfer terrestrial allsky techniques flashlight. It is part of the art of allsky photo- lated shots, or showed severe technical defi- underwater because it appeared to be the graphy to get along without any flashlights ciencies. approach that asked for the least preliminary that would result in an unevenly illuminat- tests and training. Preliminary Thoughts The challenge of shooting any photo- Preparations graph underwater is really trifold. An ordi- First came the choice of a camera. Due to nary diver has to watch out for currents and difficult overall exposure times, allsky pho- fragile coral twigs while monitoring the lim- tography demands an inflationary amount ited capacities of his life-support system. An of raw imagery. Since it is not possible to underwater photographer has to keep in change a film roll underwater, we chose to mind the optical properties of seawater that use a digital camera. We also wanted to have alter his results in color, field of view, and immediate proof of the outcome while still detail, while he needs one eye and hand for in Egypt to be able to correct mistakes. With his camera all the time. A planetarian shoot- a limited budget and the need for a fisheye ing allskies has to look for the right distance, lens combined with high resolution, we The camera system we used in Swit- angular elevation, and overall light dynam- chose the Nikon Coolpix 5000 with its zerland. Image courtesy Tilman ics of his subject. 16mm fisheye converter, together with the Göhlert. March 2004 Planetarian 13 ed scene, regardless of a stationary or rota- week we produced the raw material for underwater allsky, the objects should have a tional mount. Our itinerary would not have about fifteen allskies. much higher angular elevation (i.e. they allowed us to carry several heavy flashlights We usually divided the equipment among have to be much closer) than on land, as the up and down the Nile Valley anyway. us. Once we had reached a spot that seemed visibility is decreased by the water. Doing so, promising, the diver carrying the camera we became dependent on a seventh shot to Practical experience started to measure the exposure for the the zenith. Before flying to Egypt, there was an oppor- major features, especially the darkest and Unfortunately we did not gain usable tunity to do some practical fieldwork at the brightest spots. Meanwhile the other one set material on the first dive, which was at one Verzasca and Maggia valleys in southern up the tripod, unfolding it in the midst of of the best locations. The following days we Switzerland. The area features mountain the water column and landing it on a sandy stayed in depths of 5 to 25 meters. The reefs rivers that have formed breathtaking cav- spot. The whole procedure reminded us we visited were more-or-less steeply sloped, erns, holes, and gorges, cutting their way more of a moon landing than of prepara- sometimes followed by a drop-off. We pre- through richly patterned gneiss formations tions to take some photos. While it is very ferred sandy spots surrounded by coral of the southern Alps. For this project we important to set up the tripod evenly on blocks in each direction so we could get a teamed up with passionate underwater pho- land, one lacks a clearly marked horizon decent view without the danger of destroy- tographer Tilman Göhlert. He achieved great under water. It therefore does not matter if ing coral. One highlight was an underwater results using the Nikon F801 and Ikelite the rotational axis of the camera is not exact- cave we photographed at Ras Mohammed. housing. Yet the limited number of expo- ly vertical. Once we had determined an ex- Its most difficult light situation required two sures of the analog camera greatly limited posure, the camera was screwed onto the tri- complete series of different exposures as well the quantity of the outcome, and we had to pod head, and a couple of low-resolution as some single shots at maximum shutter restrain ourselves to just one uniform expo- samples were made to control the outcome speed. sure per location. Strong currents, very nar- on site over the LCD display. Then we shot To complete our topical range of under- rowly spaced settings, as well as sediment our round of six pictures at optimum resolu- water scenes, we set out for a wreck in the perturbation by the divers, made the dives tion, holding our breath to prevent bubbles Strait of Suez. The SS Thistlegorm is regarded technically demanding. from entering the field of view. To overcome by many as the “Holy Grail of Wreck problems in the zenith region during stitch- Diving”. Sunk during WWII, it is famous for On assignment ing, we also shot a view straight up. In order its state of preservation but just as infamous After a highly productive week on the to stay out of sight, the whole dive group for the currents and challenging water depth Egyptian mainland, the diving team separat- including the photographer performed a bal- at the site. We had the chance to explore it ed from the others who would continue at let around the tripod. on our own on two dives, during which we the ancient sites for a couple more days. We On the first dive, we tilted the camera up took allskies of the propeller and bow as well had chosen dive spots around Sharm el about 30°. This trick makes a difference to all- as of its spectacular cargo from motorcycles Sheikh and Ras Mohammed National Park at skies shot with a single 180° fisheye lens by to railroad cars. The advanced depth as well the southern tip of the Sinai Peninsula. The avoiding stitching; this way one receives a as the weight of the heavy allsky equipment locations in Switzerland were shallower than dome original that covers roughly 210° of made us use up our air quickly – air con- six meters, but we now descended to much vertical field of view, which resembles a sumption is a major issue doing underwater greater depths.