Monthly Archives: August 2015

  • Get Close, Then Closer Still!

    It’s not unknown for experienced and often professional photographers to come to Ocean Leisure Cameras, seeking out an underwater housing to enable them to take their camera underwater. We are always pleased to help._FFF6172 Nevertheless, often these people are acting under the misapprehension that in order to get good pictures whilst fully immersed in water they need to do little more to adjust the techniques with which they are familiar when working surrounded by air, than to keep their camera dry. This is not the case. Water is a very different medium to air. For one, it never has the clarity of air, neither does light pass through it without being absorbed. That doesn't mean it’s simply darker. Water absorbs light selectively. Light passing through couple of metres of water will have its spectrum distorted as the long wavelengths at the red end of the spectrum get filtered out. A few more metres and the green element is lost. Finally, only the short blue wavelengths of light penetrate very far. that is why the clearest seawater looks blue when viewed from the top. A colour-correcting filter, white-balancing in the camera or adjusting during post-production of a RAW file in the computer can help immensely when photographing in the relative shallows. The detritus in solution in the water also acts as a diffuser. Natural light underwater naturally always comes from above but often it is flat and uninteresting. Underwater, the photographer needs to add some artificial light not only to restore the natural colours but to add contrast to the photographs he takes. You might take an enormously powerful underwater flash or strobe with you but its range is still limited. Just like light from the sun, it will be filtered blue by the time it has passed little more than a couple of metres through the water t the subject and back again to the camera. So the cardinal rule of underwater photography is to get as little water between your camera and what you are photographing. Get close, then get closer still. In order to restore and image of the whole subject, it’s necessary to use a wide-angle lens - and one as wide as possible. These can be either ancillary wet lenses or prime lenses behind a dome port. Long focal-length lenses are simply of no use unless you are using a macro lens. Here’s an example of a photograph taken by natural light in the gin-clear waters off Cyprus. The Eastern Mediterranean has some of the lowest plankton levels of any seas in the world.

    Diving off Cyprus Diving off Cyprus photographed with natural light and white-balanced..
    _FFF1621 Even here in bright sunlight close to the surface skin tones are looking pallid and shadows filled in.
    Once you get a bit deeper, as in these pictures taken in Truk Lagoon in Micronesia, you’ll notice that the light from the off-board flash no longer reaches the diver and at a distance she is reduced to almost little more than a shape without detail, even though the picture was taken with the widest-angle lens available and she is little more than four metres distant.
    Diver on the wreck of an armed merchantman in Truk Lagoon. Diver on the wreck of an armed merchantman in Truk Lagoon.
    At a distance of only a few metres the diver is almost monochromatic. At a distance of only a few metres the diver is almost monochromatic.
    The nearest part of the coral encrusted deck gun is lit sharply in full colour but the mast behind is almost lost in the mist of particularly clear water. The close-up has been cropped to replicate the angle-of-view of a 60mm (standard) lens on a full-frame camera. Once you find yourself in water that’s not as clear as in the two previous examples, the difficulty in using anything with a focal length of a standard lens or longer becomes even more apparent. SafetyStop SafetyStopThis is because the water is not clear and affecting the contrast and sharpness of the image (as in the image above). The solution is to get closer, use a wide-angle lens and add contrast with an ancillary light or underwater strobe.

  • Practice Makes Perfect.

    78-79-extraYou should practise basic safety skills such as clearing your mask and regulator mouthpiece whenever you can. Both are essential skills and a swimming pool is the best place to practise them. If you are a member of a diving club there are usually pool sessions once a week. 92-93-5Removing and replacing an mask successfully underwater is one of the most difficult tasks that a new diver has to learn. There seems to be a psychological barrier to overcome which is probably a result of the mammalian reflex that tells you to hold your breath when you feel water on your face. The trick is to do in easy stages. Start by lifting the skirt of your mask to let a little water in and then blow that water out with air from your nose. When you are confident with that stage, try half filling your mask and clearing it.78-79-extra3 Do not remove your mask under the water until you know you can clear it easily and even then for the first attempts try submerging from the surface with your mask in your hand rather than taking it off when fully immersed. Eventually, you will be able to take your mask off completely and swim around the pool, breathing the air from your regulator. You will be amazed how competent you become. The swimming pool is the ideal environment in which to practise swimming with neutral buoyancy because it is more difficult to do properly in shallow water. You would have been shown in your first wet lessons how to do fin-pivots. Achieving neutral buoyancy is the essence of good diving. 92-93-3Time underwater in the pool allows you to become totally familiar with your equipment. It is worth experimenting with different ways of rigging it. You can practice taking it off and getting it all back in place while you are still submerged. This may not have any practical application when you are diving in the sea but it helps build your confidence. Another good exercises is to try breathing from a free-flowing regulator. You do this by tilting your head to one side to allow access to escape while pushing the purge button fully to simulate an uncontrolled flow of air.84-85-extra Practise emergency swimming ascents by swimming horizontally, one arm outstretched while you exhale from your mouth all the way. Make sure to keep your regulator your mouth in case you get it wrong. A simulated swimming ascent is best done horizontally because it removes the hazard of pressure changes as you go up. Remember never hold your breath while breathing compressed gases.92-93-4 Remember that old golfing maxim: The more you practise the luckier you get. Practise your skills until they become second nature and you will enjoy your diving without anxiety. Happy Diving!

  • Diving in the Dark

    Goatfish in its night clothes. Goatfish in its night clothes.
    Lighting up the detail of the reef at night with an underwater light reveals everything in a full spectrum of vibrant colour that you would never see in daylight filtered blue as it passes through the water. At the same time, many creatures of the reef are nocturnal. They include predators such as white-tip reef sharks and moray eels that are active, hunting at night. Crinoids such as feather stars and basket stars creep from their daytime hiding places to feed on plankton.
    An Octopus hunting out on the sandy seabed at night. An Octopus hunting out on the sandy seabed at night.
    It's at this time that the coral polyps come to life, protruding out from their hard coral structure, waving their arms.
    A marble ray feeding in the sand at night in the Maldives A marble ray feeding in the sand at night in the Maldives and oblivious to the presence of divers.
    Strangely, many of the more timid animals seem less aware of the presence of divers at night and seem mesmerized by a diver’s light. Other creatures can take advantage of this to make their hunting easier. Some of the most commonly encountered animals include rays feeding and turtles browsing, goatfish probing for their supper in the sand and crabs and lobsters parading out in the open. It’s also at night that the fascinating octopus stalks its supper, a meal of shellfish. Some  animals are considered special quarries for divers. These include the flashlight fish of the Indo-Pacific region, the rosy-lipped batfish in the American Pacific, and Spanish dancers - huge nudibranchs that are usually coloured bright red or pink and carry shrimps on their backs. Mandarin fish too  are only seen in the dark when they break cover of the coral rubble for a moment to mate in open water.
    A Spanish dancer is a large nudibranch A Spanish dancer is a large nudibranch
    The problem with getting a glimpse of these last two night stars of the tropical marine environment is that any white light will scare them back into hiding. Nowadays, some dive lights and video lights come with alternative red beams that the fish don’t appear to see. A typical  example comes in the form of the i-Torch Pro6+ although there are many others to choose from.
    Mandarin fish photographed with the aid of a red aiming light. Mandarin fish photographed with the aid of a red aiming light.
    Of course, if you video any subject by the light of a red lamp it will record as red but if you are making still photographs you can line up a subject under a red aiming light and then capture their image with a pulse of white light from an underwater flashgun or strobe.
    Caribbean spiny lobster Caribbean spiny lobster
    What's the difference between an underwater video light and a diving light? The diving light will have a narrow beam which is not usually very even. It gives a hotspot of focused light and a peripheral beam that may be composed of concentric rings. It allows us to concentrate on one subject whilst being aware of what else might be going on around us. On the other hand a video light gives a wide and perfectly even beam in a colour-temperature range that is acceptable when viewing the footage later. If you used an ordinary diver’s light for video, the image would be unacceptably patchy. Equally, a video light does not punch its way far into the water and only a has a limited range. You'll see the weird and the wonderful at night. Animals such as this decorator crab, self covered with its adornment of sponges.
    Decorator crab Decorator crab disguised with a covering of sponges.
    Whether you want a light for diving or for underwater video-making, we hold a large selection at Ocean Leisure and Ocean Leisure Cameras. If it's a video light you need, you'll discover a choice from 1000 lumens output to a massive 6000 lumens. If you want a diving torch, we stock a wide selection of those too.

  • The Amazing Rhinopias

    _DSC8312 Rhinpoias Aphanes or Lacy Scorpionfish
    The Lacy Scorpion fish or Rhinopias Aphanes is found in the waters of Papua New Guinea and West Papua. Unlike a lot of colourful marine life, you don't need a macro set-up to get good pictures if you come across one because they can be up to 25cm in length. They are a benthic species in that they tend to rest on things rather than swim. However they often get about by hopping around on their pelvic and pectoral fins. Despite they fact that they appears to be very colourful in these photographs they are masters of disguise and although they often pose precociously atop sponges and coral heads, you can easily pass one by because under natural daylight they are quite hard to see. They were first brought to the attention of marine scientists by British/Australian diving pioneer Bob Halstead who after a career as a schoolmaster took to running scuba diving expeditions and later skippering his boat mv.Telita, taking divers on scuba diving charters around the waters of the Coral Sea, embarking his passengers at Port Moresby. Among other things, Bob Halstead has written several books on diving around PNG.
    Lacy Sorpionfish or Rhinopias Lacy Scorpionfish or Rhinopias Eschmeyeri
    After he started noticing these flamboyant fishes he sent some pictures that he'd taken to experts at the Natural History Museum in London who confirmed it was a previously undescribed species. In fact there are several sub-species. Bob is known for his insightful analysis of diving practises and also for his humour. One of his most well-remembered quotes is: "If you can't take a joke, don't take up underwater photography!" The first time I visited PNG I made it my business to photograph some examples of this keynote fish but after a lot of searching and no luck came back with an article for UK's Diver Magazine entitled 'The Rhinopias is Missing!' I kept my sense of humour. The next time I stayed at the Loloata, a resort on its own island in Bootless Bay run by Australian Dik Knight, the dive guides made it a matter of honour that they did not fail to find me an example to photograph. They took me to a reef called Dinah's Delight, named after Bob Halstead's first wife, also an accomplished scuba diver in her own right and it was if all the Rhinopias in various different sub-species had come out on parade. _DSC8421   To photograph these wonderful looking fish you need a a wide-angle lens so that you can get as close as possible and an underwater flashgun or strobe so that you can reveal them in their full spectrum of colour. The other things you will certainly ned is a pair of sharp eyes and a lot of patience whilst looking for them because in natural daylight they easily merge with their background.._DSC8406 One last point: Rhinopias are said to be the Holy Grail of marine aquarists who like nothing better than to keep one in an aquarium because these delicately coloured fishes are so pretty. Let's keep them in the ocean where they belong. (The pictures here were all taken with fish-eye lenses behind dome ports and with ancillary off-camera flashguns.)

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