This year's winter escape from chilly Adelaide saw us winging our way to the Vanuatu archipelago; 80 or more exquisite islands nestled in the South Pacific 3 hours flight from Sydney. Best known in diving circles for the immense and easily accessible wreck of the SS Coolidge, for me Vanuatu held the lure of the extensive freshwater cave system on the northern island of Espiritu Santo. This system was explored by a team of local and Australian divers in the late 90's, and I was as keen as mustard to get in there. As luck would have it however, access to the caves has become impossible due to a complex web of issues revolving around land ownership and local custom. So the Coolidge it was for me, not bad for a fallback plan!!

The trip offered me the perfect opportunity to test my new Subal D10 housing and the Nikon D100 digital SLR from Seaoptics in Adelaide. Making the change from slide film to digital takes an enormous leap of faith for most photographers, not to mention a significant outlay in cash, so it was with some trepidation that I descended on my first photo dive with this rig.

On this occasion we stayed on Aore Island which lies a 15 minute ferry ride across the Segond Channel from the town of Luganville, Santo. Aore is simply heaven on a stick with its 17 secluded and spacious bungalows, friendly staff and great snorkelling straight out in front of the bar. Families and honeymooners alike will find a serene and relaxing base from which to explore.

Barry Holland from Aquamarine in Luganville organises diving to suit all levels of experience, and caters well for the growing technical diving set. After one or two checkout dives, Barry led me through a maze of rarely visited rooms and corridors on a personalised tour that I will never forget! Accelerated decompression on nitrox is available for appropriately qualified divers, although trimix diving is not yet widely used. The implementation of the Vanuatu Divers Code of Conduct has dramatically improved diving safety for both visiting divers and dive guides, and the "cowboy" reputation of the dive shops operating on the Coolidge is now hopefully a distant memory.

Anyway back to the Nikon D100. Although by no means a photography expert, I have had the opportunity to use several photo systems underwater now, including Nikonos amphibious cameras, housed 35mm film cameras and digital video. With this system, all my fears were unfounded! The camera and housing were a joy to use and given that the dives represented my first attempts with the system, I am really pleased.

So what was I worried about before the first dives? Several issues seem to be preventing UW photographers making the change to "high end" digital SLR cameras (although the point and shoot digital underwater cameras have become hugely popular). The first concern is the loss of the wide angle capability of the existing lenses. Because the image is reduced onto the CCD chip in the camera (the chip is smaller than 35mm film), the focal length of the lens in use is effectively multiplied by 1.5. So the viewing angle of my Nikkor 16mm fisheye went from 180 degrees to around 110, the 20mm lens became a 30mm and the 60mm became a 90mm etc. While one could argue a case for this being advantageous in the macro and telephoto lenses, underwater photographers are heavily dependent on good wide angle lenses to get close to their subjects. This minimises the amount of water (and therefore sediment) between the lens and the subject, whilst still getting the subject into the frame. All the wide angle images in this article were taken with the 16mm fisheye, and although the viewing angle is reduced, I still found the lens easy to use and the images pleasing. In fact, the peripheral distortion usually seen (and sometimes sought) with this lens is greatly diminished, and the risk of photographing your own fins or strobes was lessened! The 20mm lens seems a bit lost with this rig, as it is simply not wide enough for anything but portrait shots, but to be fair I didn't dive with it on this trip. At the other end of the spectrum the 105mm macro lens is a bit too strong. In the dirty water in which I used this lens it was hard to get close enough to my subjects, and a lot of backscatter resulted. I think the 60mm macro will become a real favourite. Nikon's new 12-24mm zoom lens will no doubt be the solution for UW use, but I'll need to save my pennies for that one.

The second concern many photographers express is the lack of true TTL metering for the strobes. I have always been heavily dependant on TTL to sort out exposures for me, especially with macro work. So how was I going to cope? Well I needn't have worried on that count. This is where the digital system shows its greatest advantage in my opinion. INSTANT FEEDBACK!! I took a few shots in the living room before I dived to get a feel for strobe power and f-stops. With this in mind I hit the water and was pretty close to the mark with my first few shots. A couple of quick changes and there it was, near perfect exposures (nearly) every time! I have learnt more in these few dives about exposure than I have in the previous 50. And the beauty is that if the shot is not right and the subject is still there, change something and shoot again. If presented with a rare opportunity, take 20 shots of the subject; no problems I still have 83 more shots on my 1Gb compact flash card at full resolution! And deleting shots you dislike on the "swim" is a moment's work. If despite this instant feedback you still can't live without TTL, a housed Nikon SB-80DX is the answer but at a price. For my money, I'll be sticking with my SB-105s. On the topic of image storage, I purchased a Nixvue Lite 20Gb portable storage device before the trip. At the end of each day I downloaded the images from the CF card into the Nixvue, then on arriving home transferred them all to my PC. It worked smoothly and faultlessly and can store 1030 high resolution images from the 6.1mpix Nikon D100 (how much would that cost in slide film??)

The third worry? Will my shots be as good as slide film and can I enter them in competitions without being labelled a Photoshop fraud? I have 2 uses for my shots. Photos that I really like I print on my home ink-jet on A4 photo paper to show my friends. Some I will also put on my website to show fellow photographers. In the past I have had to endure the laborious task of scanning the slides into Photoshop then use them from there. Comparing my best scanned slides with my new digital images, I cannot see any difference, if anything the D100 shots look crisper. So for my purposes, the digital system is vastly more efficient and satisfactory. For competition entry, images produced in the Nikon NEF format from the camera cannot be manipulated unless first changed to another format eg TIFF. This means they are as "honest" as a slide and should be treated as such by competition judges.

The final worry for anyone who has ever owned a digital camera or a computer is that will the equipment be out of date and superseded from the moment of purchase? Well yes is probably the answer, but for my money we have reached the point where the quality of the chips and the optics are as good as film for my purposes, the cost has become (just) less than outrageous, and the convenience of the system now makes the transition to digital an acceptable option. With my existing Subal ports and Nikon lenses from my Subal F80 system in hand, the decision felt right to me. Then again, I do like to have the latest toys!