LIGHTING BlueStar Torch & Photo Accessory Kit
Back in the Swinging 60s, Kodak brought out an infra-red-sensitive film that reproduced images from the heat they gave off and used a system of false colours. It was intended as a tool for aerial reconnaissance.
     It was not long before we saw trendy magazine articles illustrated with pictures of familiar subjects reproduced in the unfamiliar colours obtained by using this film outside its intended sphere of use.
     Gimmicks rarely hang around for long. Needless to say, we tired of these pictures as quickly as we tired of fashion photographs made using the medical photographers ring-flash.
     Most divers who have been under water at night are aware of the bioluminescence given off by plankton in the water. A vivid memory of mine is that of the three dolphins from outer space that swam at the bow of the sailing vessel on which I was once making night-passage near the Galapagos Islands. They were lit up by the eerie green light given off by the plankton as it passed over their bodies.
     Similarly, I remember a bioluminescent green sea-lion that swam around our boat later in the dark, when we were at anchor.
     Lots of marine animals and organisms live in association with phosphorescent zooantheles, and simple fluorescence can be found in corals, shrimps, anemones, nudibranchs and fish, even some minerals.
     What is the difference between phosphorescence and fluorescence Well, the first will emit light some time after receiving energy from another light source, while the second emits light only for as long as it is receiving energy.
     Fluorescent subjects do not emit light unless they receive light, but they can receive light of one wavelength or colour and emit it as another.
     Many coloured dyes used in the printing of packaging use fluorescence to make them especially bright. A particular bugbear of commercial photographers is the bright yellow or green ink used in some packaging that photographs as dull brown.
     The trick would be to light up a suitable subject with a suitable wavelength of light that would cause it to fluoresce, and at the same time to stop other visible light from reaching either your eyes or the lens of your camera.
     Enter Charles Mazel PhD, who began dabbling (his words) with underwater fluorescence back in 1975 but launched into it in earnest only in 1986. He is a research scientist and founded NightSea to share equipment and techniques with others in the sport and scientific diving communities.

Exclusively macro
NightSeas BlueStar torch uses the latest in high-intensity LED technology, combined with focused optics, to produce an ultra-bright, ultra-tight beam. It uses three C-cells as batteries, with a burntime of 10 hours. A barrier-filter for wearing over your mask is included.
     The photo accessory kit includes an excitation-filter that fits over your flash or video light, and a barrier-filter that screws on to your camera lens (I used the standard Nikon 52mm screw mount). There is also a guidebook to underwater fluorescence photography.
     Daylight overwhelms any likely effect, so this is something to try out on a night dive. The effect is also quite weak, so youll need to position your flash close to a subject. This confines its use almost exclusively to macro-photography subjects.
     Under water on a typical coral reef in the Red Sea, I found that without the filter over my mask the BlueStar torch had a particularly penetrative beam. Those back on the boat reported knowing at all times which light source among the many others out there was me.
     However, with the mask-filter in place, I was reduced to something akin to an underwater version of a ride on the Ghost Train at the Hayling Island Butlins holiday camp of my childhood.
     I was unimpressed then, and I was less than stunned this time. Fewer parts of the coral fluoresced than I had anticipated. Almost without exception the sleeping fish did not seem to fluoresce either, apart from a single dragonet that I found hiding under a rock.
     Then, over a sandy bottom, it suddenly seemed as if I had been given the senses of a sting ray. I saw tiny animals hiding in the sand that were totally transparent, and therefore invisible with the normal spectrum of lighting from my traditional divers torch. They glowed a ghostly fluorescent green when lit by the BlueStar torch and viewed through the mask filter.
     Photography proved difficult. I found it impossible to focus my macro-lens-equipped camera. I needed to use white light for this, which was still difficult because the camera lens was fitted with its heavy yellow filter.
     I was limited to inanimate subjects, dousing the white light of the focusing light immediately before I released the camera shutter. In fact, overall, it made night-diving rather hard work.
     Charles Mazel has obviously pursued the technique over a long period and is now getting some fascinating results. I got him to send me an example of a shot of a bristleworm taken using both white light and fluorescence. If you decide to have a go with the kit, be aware that you may not achieve satisfying results without a period of experimentation.
The BlueStar torch costs around £70, including a barrier-filter for your mask, and a photographic accessory kit with flash exciter-filter and camera lens filter costs around £180.
  • NightSea, www.nightsea.com

  • Divernet Divernet
    These pictures by Charles Mazel show a bristleworm shot using white light (top) and fluorescence
    + A novel way of seeing things in the dark

    - Will the novelty soon pall