Mastering Silhouettes in Underwater Photography

Creating striking underwater silhouettes is one of the most visually compelling techniques in underwater photography. Achieving these dramatic shots requires a good understanding of light behavior underwater, effective positioning, and creative use of natural elements. Here’s a comprehensive guide on how to master this technique.

Understanding Light Behavior Underwater

The key to capturing a great silhouette is understanding how light interacts with your environment. Underwater, light behaves differently compared to on land; it scatters and loses intensity the deeper you go. The water absorbs colors starting with reds, moving on to oranges, and eventually, the blues, leading to a predominantly blue-green environment. To create a silhouette, you need to position your subject between your camera and a strong light source, typically the sun. The ideal scenario is to have the sun directly behind your subject, creating a sharp contrast between the subject and the background. Positioning the sun behind your subject creates a striking backlight, perfect for capturing silhouettes. At shallower depths, this technique also highlights natural sunrays surrounding the subject.

This contrast is enhanced by the fact that underwater subjects will appear darker due to the absorption of light, especially when they are not directly lit by artificial sources such as strobes. Therefore, using only natural light is crucial in silhouette photography underwater.

We're often taught to use sunlight to our advantage, but this technique flips that approach, teaching you to shoot against the light—a powerful skill for mastering more advanced techniques.

Camera Settings and Equipment

Selecting the right camera settings is essential for capturing stunning silhouette shots. Start by using a smaller aperture (higher f-stop) to keep both your subject and background in sharp focus, ensuring a clean, defined outline. A faster shutter speed is key to freezing motion and maintaining crisp edges, especially underwater, where currents and movement can blur details. This also limits the ambient light, preventing blown-out highlights. When relying solely on natural light, without strobes, you're not bound by flash sync speeds, allowing you to shoot at much faster shutter speeds for optimal results.

Shooting in RAW format is highly recommended as it allows greater flexibility in post-processing, where you can adjust exposure and contrast without losing quality. Additionally, turning off your strobes or external lights is essential since you want your subject to remain dark against the bright background .

Positioning and Composition

Proper positioning is crucial for an effective silhouette. The best time to shoot silhouettes is when the sun is low in the sky, either early morning or late afternoon. At these times, the sunlight penetrates the water at an angle that enhances the chances of a strong silhouette. You should be below or level with your subject, shooting upwards to capture the light filtering down from the surface.

Compositionally, placing your subject off-center can create a more dynamic image. Including elements like the surface of the water or the sandy bottom can add context to the scene, making it more engaging. Incorporate leading lines, like rays of sunlight or the contours of coral reefs, to guide the viewer’s eye through the image.

Ideally, add your subject directly in front of the strongest part of the light, this will give you a much more pleasing result.

Also as a general rule, you’re shooting towards the surface when taking these types of shots, therefore we are in an unnatural position and we need to consider our own bubbles as they will often be in the scene. Regulating breathing and timing the shot is critical with the ultra-wide lenses we use for this type of shooting.

Alternatives to Sunlight

Artificial light can also be a powerful tool for creating silhouettes. Off-camera strobes and video lights are commonly used in cave and wreck diving to help a subject stand out from the background, allowing the shooter to craft a "fake" silhouette. This technique is highly effective and versatile, especially in darker environments where natural light is limited. Additionally, you can use the large, powerful lights often found on liveaboards as backlighting when returning from night dives, adding a dramatic effect to your shots.

Subjects for Silhouettes

The obvious subjects for silhouettes are people and large animals, both can work really well for these types of shots. Sharks, whale sharks, rays and turtles are very commonly used. Any subject whose shape is graphically obvious.

Try to be creative in your silhouettes. We often shoot shipwrecks with the sun coming over the photographers shoulders to create nicely lit wreck shots, but you can shoot against the sun to create outlines of wrecks as strong silhouettes against the seabed.

Silhouettes within Frames 

Once you haver the basics of ambient light only silhouettes, it is then possible to combine artificially lit subjects, with ambient light backgrounds and silhouettes. The classic version of this combines a strobe lit reef scene close to the lens, along with shooting into the sun and silhouetting a smaller diver model in the background.

In order to do this you will need to use very powerful flashguns to counteract the settings you are using to control the ambient light that you have from the sunlit background, this is one of my favorite types of shots to take.

Post-Processing Tips

In post-processing, emphasize the contrast between the subject and the background. Decreasing the blacks and shadows while keeping highlights bright can make your silhouette stand out more. Be cautious with color adjustments to retain the natural blue tones of the water unless you’re going for a creative effect.

Cropping can also be an effective tool in post-processing. By removing unnecessary parts of the image, you can direct focus more precisely on the silhouette, enhancing its visual impact. However, it’s always better to get the framing as close to perfect as possible in-camera.

Often when processing these types of shots it works well to add in a touch of clarity as this will increase contrast and make things like sun-rays more defined. You also often see a lot of black and white conversions, but as Alex Mustard always says, when converting an image to black and white ensure that you are actually enhancing an image. I personally think this is often done to compensate for poor technique in the shooting process such as over exposing the ambient light

Practical Considerations

Safety is paramount when shooting underwater silhouettes, as it often requires diving in less-than-ideal light conditions. Ensure you’re comfortable with your buoyancy and aware of your surroundings to avoid accidents. Additionally, consider the ethical impact of your photography on marine life, ensuring that your quest for the perfect shot does not harm the ecosystem.

Conclusion

Mastering underwater silhouette photography takes practice and an understanding of the unique challenges posed by the underwater environment. By effectively using natural light, optimizing your camera settings, carefully composing your shots, and being mindful of both safety and environmental impact, you can capture stunning silhouettes that showcase the beauty of the underwater world. With time and patience, these images can become a powerful part of your underwater photography portfolio.