SAA Policies & Guides
Photography:Lighting the underwater world.
How to make the best of natural light in your pictures.
Marine animals and Divers
make good silhouette subjects.
To create exciting underwater images you need interesting lighting. A good understanding of how water is affected by light, be it from sun or flash, is essential. Most underwater photos you see are illuminated in some way by flash, which brings out the vibrant colours so often associated with marine pictures. But before exploring flash photography you should try natural light shots. Many underwater subjects can only be taken with natural light, others lend themselves to its use, and most wide-angle shots rely on the background being illuminated by the sun. You will also gain an understanding of the limitations that water places on underwater photography.
When sunlight passes through the surface some is reflected back and if the surface is at all rough, or the sun is low, even more light is lost. What proportion is left then travels through the water to light our domain.
The greater the distance light travels (in any direction) the more colour is lost and red is most noticeably affected (because of its long wavelength) even within a few cm. of water and by 10m it is all gone!
Water is not totally clear for it contains suspended particles, plankton and sediment, which absorb and scatter the light so reducing the visibility.
When shooting natural light shoots there are two ways to overcome the above difficulties of light reflection, absorption and diffusion. It is possible to use filters to bring back lost colour or you can shoot monochrome images (which black and white photographers have been doing for years).
Using Filters underwater.
These are only useful for shallow water (less than 4m) shots, and they work by selectively removing blue in tropical waters (or green in temperate waters) thereby re-distorting the light passing though them towards the red wavelengths. In blue waters the colour-correcting filters are red and for green waters magenta. When using them you will have to calculate the total light path i.e. the distance from the surface to your subject and then to the camera. For every 40cm of light travelled you have to add five units of colour-correction filter up to a practical working maximum of fifty units, this would be known as a CC50 (red or magenta) filter. It would allow you to shoot a colour corrected shot with a total light path of 4m i.e. you are 3.5m deep and 50cm away from your subject. If your light path is less then you have to use a weaker filter or you will produce a shot with a red/magenta cast. When used correctly these filters give wonderful natural shots.
The monochrome image.
This stunning atmospheric image
given the right lighting conditions
is straightforward to capture on film.
Colour film underwater monochromatic shots will be composed of various shades of blue or green and produce good quality images up to half the distance of the available Vis.
When taking monochromatic shots good subject separation is essential, meaning that your subject needs to be noticeable in relation to its background. Look out for shade separation such as a dark subject against a light background which could be a white sandy bottom or open water. Do not be tempted to use colour separation; even though you can see it’s a red fish sitting on green weed, your film won’t record it this way.
Most monochromatic shots are taken using the water column as the background. It is important when shooting your subject that the whole of it is framed by open water, otherwise it will merge with the darker parts of the shot and become lost. You can often prevent this from happening by being slightly lower than your subject and shooting upwards.
When relying on natural light the sun’s position has a crucial effect on the results you will achieve. If the sun’s light is coming from behind you, your subject will be well illuminated and appear light against a dark deep blue background. Try and be as close to you subject as possible to prevent any shades of blue (or green) from merging with those of the background.
The most striking monochromatic images, I feel, are achieved when the subject is placed in front of the sun. The subject’s black form is then silhouetted against a pleasant blue (or green) background or sunburst. These images are relatively easy to obtain and if the sun is not to be included in the picture take a light meter reading from the water above your subject. This will produce an underexposed dark subject against a bright background.
If the sun is out it will appear underwater as a bright ball of light surrounded by sunrays. By placing the subject between your lens and the sun you can create a stunning silhouette with the sun’s rays radiating from around it. Shutter speeds of 1/125th or more should be used to freeze these dramatic sunrays. When taking a light reading it is best not to take it directly from the sun but from 20° to one side. You should also bracket your shots, for although most will come out there will be subtle differences.
Natural light shots are simple to take and if treated artistically can result in stunning atmospheric images.
| First clicks | Shooting small 01 | Shooting small 02 | Getting the Big Picture |
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| Building Pictures | Lighting the underwater world | Colouring the Ocean | Balanced Light photography |
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