10 Tips for starting and improving with underwater photography

Since underwater photography equipment is often expensive, it's better to devote some time to it before diving, especially when it's brand new! Water, salt, wind, sand - diving conditions spare nothing. Particular attention must be paid to the seals, which need to be checked before each outing, especially the seal of the rear opening. No need to lubricate the seals before each outing, since excess lubricant can actually hinder the watertightness by attracting dust from the surroundings. Whether you dive from the shore or a boat, the choice of a transport box is crucial. Choose a modest-sized box so that you can easily put it under cover on the boat (often under the racks provided for the tanks). On the beach, the box will have to provide better protection against sand getting in and damaging your equipment. Last important thing, if you don't want to be worrying about things during the dive, it's best to prepare your equipment at home (camera, housing, flashes, ...). There's nothing more stressful than worrying about water getting into your equipment on the first dive. It also prevents nasty surprises on the spot : drained battery, poorly connected flash cord, memory card left at home...

Other than taking a quick shot as the boat gets underway, underwater photography requires a minimum of technique and ease. Underwater comfort is an essential prerequisite that includes good control of the BCD and consequently of your buoyancy under water. It's also best to let your dive group partners know beforehand that you plan to take pictures. Indeed, you'll tend to stop more often and be less attentive to others. Caution!

In addition to your ability to move comfortably under water in order to get better results and have less difficulty when approaching your subjects, your underwater behaviour can also have a direct impact on the environment. Photographing doesn't mean interfering with the environment and disrupting the local flora and fauna. That would be like coming back with images that glorify the environment while damaging it...

On the contrary, it's in shallow waters, ideally between the surface and a depth of 10 m, that the light and visibility conditions are often the best. Close to the surface, the sun creates splendid light rays, which are very photogenic. The colours will also be more beautiful.

To make the best of these conditions, some basic rules are good to remember. Have the sun at your back when you shoot to avoid excessive back light. With optimum brightness and if your camera allows it, try to increase the shutter speed to avoid blurry pictures. You'ill quickly realise how much undersea life is moving around you ! Since camera sensors are increasingly efficient, don't hesitate to turn the ISO sensitivity to higher values ​​(up to 400 or 800 ISO without problems). Finally, if particles are too visible in your photos, turn off your camera's built-in flash and you'll see how the result of your first pictures improves.

From a few metres below the surface (from 3 m), the sun's rays are filtered to the point that certain colours such as red quickly disappear. The flash, whether built-in or separate from the camera (external), then becomes essential, even under a bright sun and in crystal clear water. We'll start with the built-in flash. Again, don't hesitate to get closer to the subject so as to capture it in all of its glory. A good flash has a maximum range of 1 metre. The diffuser integrated in many housings is very useful and, in addition to diffusing the light well, it serves to limit the unlit area created by the flash and the window of your housing. The purchase of one (or even two) external flashes significantly increases the quality of the images and avoids the slightly harsh light of built-in flashes. Good flash positioning is a topic of much debate, because the beginning photographer will soon be faced with the "particle" issue caused by the flash. Positioned on the sides and slightly back from the front of the housing (and not in the optical angles like the built-in flash), remote flashes offer a very uniform light without highlighting particles. Good to know.

Don't be surprised that a good flash costs several hundred euros. This is the price to pay for quality colours.

This photography technique is undoubtedly the most immediately gratifying. All you need is a simple camera in "macro" mode. You'll instantly get impressive pictures, since the colours and the details that emerge look absolutely stunning. The difficulty with pictures of this type is ultimately not the technique itself but the choice of the subject. Indeed, it's quite easy to miss a bunch of jewel anemones or a tiny blenny. And then there's the current or swell that can disrupt your focus on the subject. As for the composition of the picture, it's not easy through the "mouse hole" of an SLR eyepiece. The owners of compact cameras are better off, for 2 reasons. The viewing mode using the rear screen often performs better than on an SLR. In addition, the small size of compact sensors greatly improves the depth of field, providing a wider area of ​​sharpness. However, there's a solution to every problem, and the owners of an SLR will also be able to purchase an external viewfinder, as high-performance as it is expensive!

This type of photography involves using a wide-angle lens, which is very popular in underwater photography. For the best performing compact models, there are housings that can be fitted with additional optics that screw onto the front of the camera window. From wide angle to fisheye, these add-ons (also called "wet" lenses) used on compacts have the advantage that you can put them on or take them off under water. Conversely, the use of an SLR means having to choose your optics before diving. This isn't really a constraint, but can be a drag when a big subject presents itself and you're using a 60 mm or 105 mm macro lens... All major SLR brands, Nikon, Canon, Sony, etc. have various lenses that can be used under water. With a sensor in APS-C format, it's best to opt for a focal length of 15 mm, ideally a 10 mm fisheye or better still a 10-17 mm zoom, which will give you more possibilities. The advantage of a wide-angle, besides the width of the field covered, is the possibility of getting very close to the subject. Thus, at only 20 or 30 cm from the subject, the flash delivers all its power in the foreground and it's always possible to include more of the background in the image.

Besides the quality of the light, composition is essential tfor better understanding and greater clarity of the image. A beautiful and properly composed photo will be much more impressive to the viewer. Beginners tend to take many shots in the hope of getting one right. Unfortunately, this is seldom the right method ...

Choice of subject and view angle are far more important. Often, by slightly turning the camera or by tilting it vertically, the colours can change and each element of the picture can magically fall into place. Remember: there's no good picture without a good subject. It must stand out at first glance. Next, focus on giving depth to the image by including, for instance, another diver or a background of a different colour.

The shutter speed, ideally adjustable via the M mode of your camera, will make it possible to adjust these 2 aspects. It's by altering the speed that you can freeze the subject's movement or, by contrast, deliberately (or not!) create a blur of motion. But be careful - changing the speed will also affect the brightness of the background. With a fish-eye, you shouldn't hesitate to go down to 1/15 of a second for static subjects. A flash obviously helps to freeze the movement. In backlight and with bright lighting we will, whatever happens, be limited by the flash sync of the camera, varying for SLRs between 1/200 and 1/500th of a second depending on the models. If the light is still too strong, adjust the aperture by closing it one notch. This 2nd parameter obviously plays the same role as the speed with respect to the light that it lets pass to the sensor, except that the opening (of the aperture) will be dependent on the power of your flash. The more powerful it is, the more you'll have to reduce the opening (= aperture), from f5.6 to f8 for example. This is why the most advanced external flashes have partial power settings, which are very effective for modulating the intensity of the lighting. The flash, on the other hand, is only used to illuminate the foreground. The intensity of the blue or green colour of the water depends exclusively on the choice of the speed, since the aperture will have been previously set according to flash power. Phew!

Underwater photography equipment is not particularly fragile. However, whether it's a watertight design, a plastic or aluminium housing, all models have to face the same challenges when dealing with sea water. Salt gets in absolutely everywhere, around the springs of push buttons, and on all the metal parts very quickly forming a layer of verdigris which becomes very harmful in time. Inevitably, without a good rinse after each outing, your equipment will be damaged. The springs will become harder, the flash cords more difficult to attach. The simplest thing to do, even before maintening the joints, is to soak your equipment after each dive. A good soak of about thirty minutes in fresh water allows all of the salt to dissolve. You can even do this in the camera's transpor boxt ! After soaking, without removing the housing from the water, be sure to operate all of the controls and other buttons repeatedly to extract as much water as possible around the sensitive parts. This is the best way to proceed. A simple rinse under running water is unfortunately not very useful. For cords or other connections, be sure to unscrew them carefully after each use. This prevents the connectors from being "soldered" to the base. If you follow these guidelines, your equipment will work well for several years.