Once the complete camera package is set up and ready, all that remains is for the marine life to perform on cue. Artificial light must be powered by surface generators and supplied via cable. Battery lights are not going to get the job done. Lighting a scene without making the use of artificial light obvious means spreading the light over an enormous frame. The 30mm lens covers 180 degrees corner to corner. Lighting set-ups needn’t be brighter than for other formats, but they do need to be much wider. Once the camera is mounted on the tripod, the next step in the set-up process is to bring in artificial light-a staple of most large-format underwater films. And even though the 30mm is a fisheye in the 15/70 format, it still has much more limited depth of field than wide-angle lenses used for smaller formats. Depth of field, when using lenses with focal lengths longer than 50mm, makes critical focus nearly impossible to maintain unless the camera is locked down. Though most underwater 15/70 film is shot using the 30mm full-frame fisheye lens, longer lenses can be useful for varying perspectives. Water movement is not the only reason to use a tripod underwater. Once, while making the IMAX 3D film Into the Deep, one of the two-inch-diameter aluminum tripod legs sheared in half as surge pressed against the camera housing. For most situations, we find it necessary to add 20 pounds of additional lead to each tripod leg, which still might not be enough. Our underwater tripod weighs about 70 pounds, but even that amount of weight is often not enough to stabilize the camera in mild surge. For stationary subjects, however, a tripod becomes very useful, if not absolutely necessary. The director must either accept the back and forth movement of the image, or else put the camera on a tripod-an impractical option, usually, for filming moving subjects, but since surge will often propel a moving subject back and forth in synchrony with a hand-held camera, the movement can be acceptable. In mild surge it often becomes impossible for a cameraman to hold an underwater 15/70 camera still. The shallower the bottom, the stronger the surge for a given wave size. The problems created by mild currents are secondary to those created by surge, the back and forth movement of seawater created by passing waves. Though this succeeded in propelling the camera to shooting locations faster, it also resulted in a camera system that was unwieldy once we arrived at the sites, unless disassembled for each shot. We’ve experimented with increasing the system’s mobility by attaching diver propulsion vehicles to the camera housing. While making the MacGillivray Freeman film, Coral Reef Adventure, our Fijian dive guide often beckoned us across the reef toward a subject she had discovered, only to be disappointed when the film crew gave up after swimming for fifteen minutes against an almost imperceptible current. Even if two divers manage to pull the camera into shooting position against a quarter-knot current, the cameraman will often find that holding that position long enough to take a shot extremely difficult. Pursuing marine creatures like whales, sharks, and manta rays becomes almost laughable.įactor in the minimal amount of current, and the situation can become impossible. When swimming the camera, a strong diver can generate only two speeds: painfully slow and slower. Though seemingly weightless, it still retains 250 pounds of mass and has a great deal of surface area. Underwater, the 250-pound camera system becomes neutrally buoyant. The launching and recovering of the underwater camera system becomes a major logistical concern when choosing a boat. Boats that seem spacious when working in television formats suddenly become impossibly small when loaded with an underwater 15/70 production package and crew. This weight creates significant limitations when choosing a boat from which to dive. The IMAX Mark II camera in an underwater housing weighs over 250 pounds. One must relish challenges to enjoy working underwater with a 15/70 camera. I love making underwater IMAX films because it is so hard. But the inherent handicap a wildlife filmmaker assumes when working in 15/70 is one reason why I keep coming back for more. Having directed two underwater 15/70 films (one of which was produced by my wife, Michele) and been underwater DP on several others, I know what it is like to be bludgeoned by the cumbersome 15/70 format. If someone were to hold a competition to create the most difficult motion picture format for capturing wildlife behavior, it is hard to imagine a more creative entry than 15/70 (IMAX).
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