Blackwater photography

By Tim Barber

The first rule of successful underwater pho tography is get close. Because of its density and the presence of suspended particles, even “clear” water absorbs and scatters light much faster than air. Not only is the total available light reduced, but colors are shifted toward the blue end of the spectrum as the longer wave lengths are absorbed first. So the less water between the lens and subject, the better.

The water column that we encounter in the Aucilla River contains not only a generous supply of particulate matter, but also a chemical component, mostly tannin, which makes this “get close” rule even more important. This actually simplifies equipment choice.

To obtain a close focal distance with a generous field of view, use a wide angle lens. Think of looking through binoculars backwards where you have to get really close to something to make it appear normal size. This is the choice for rendering larger objects such as megafaunal remains or procedural shots of divers. To get even closer for small objects, use a macro lens of at least 60mm or greater. You may lose some context because of the narrower picture angle, but you can capture images of in situ material actual size.

All of the underwater photos in this issue were shot using a Nikon 8008s with an AF Nikkor 28mm f/2.8D lens (9” minimum focal distance). This was mounted in an Ikelite SLR-AF housing. A dome port was used to correct for the water’s refraction. Since the only available light at depth is provided by our 1000 watt Snooper lights, I used an Ikelite 100 A (medium intensity) strobe, hand held.

I used Kodak Ektrachrome Lumiere 100X professional slide film for its high color saturation and exceptional resolution. Kodak no longer makes this film, but told me their E100S and E100SW professional films have similar properties.

What about digital cameras? At present there is equipment capable of mounting the required lenses and approaching film’s near-seamless resolution. However they’re bulky, expensive, and underwater housings are unavailable.

I think that we regulars on the Aucilla River Project tend to take our “snapshots”, both underwater and topside, for granted. After all, we’re there in the field every day - we know what this stuff looks like. Then I consider the now priceless images of previous expeditions, say Howard Carter in the tomb of Tutankhamen or Roy Chapman Andrews’ crew at the Flaming Cliffs in Mongolia. I hope that one day our pictures will have a similar archival relevance. If not, then at least we’ve captured some great memories. But, if so, then maybe, just maybe, having to listen to Bill Gifford whine about his coffee will have been worth it.