Shooting portraits is a fairly basic technique in underwater photography, but one that often results in eye-catching images. Portraits focus on the face and eyes of your subject, sometimes the full body, and background may be included. A careful approach and perfect timing, depending on your subject and composition, are the keys to mastering good portraits.

Here are 5 tips to help you shoot the perfect portrait:

1. A macro lens (e.g. 60mm, 100mm or 105mm) is the most commonly used for portrait shots of most reef fish and all tiny super-macro subjects such as shrimp, nudibranchs and seahorses, (with an additional close-up diopter if necessary). A macro lens enables you to shoot your subject from further away, creating the best chance for you to capture a head-on angle and composition. If you're shooting a larger animal, such as a shark, turtle, or manta ray, and you're able to get close to it, then you could use a wide-angle lens. You can use a wide-angle fisheye lens for close focus wide-angle (CFWA) or even a macro wide-angle (MWA) for a unique perspective.

2. Shoot portraits from a head-on, or slightly head-on angle. Depending on the subject, this can take a bit of patience as you follow the animal, waiting for the opportune moment as it turns and faces you. Knowledge about the behavior of various species will also help you in this regard. As you stalk your subject, make sure you're ready to shoot at any moment, with the correct camera and lighting settings for the shot you're after.

3. Marine-life portraits can often look best without distracting backgrounds, so you may want to time your shot for when the subject swims off the seabed slightly, in order to isolate it against a blue or black background. For a subject close to the seabed, surrounded by other distractions, you could shoot with a very low f-stop, which creates a very shallow depth-of-field and results in an image with soft “bokeh,” or blur.

4. When people think of portraits, many naturally think of a vertical “portrait” orientation, but a horizontal (landscape) orientation can also be effective for underwater portraits, especially when shooting some larger animals that may be difficult to compose vertically, such as a sharks or turtles.

5. Eye contact is very important for this technique, so it's essential to focus sharply on your subject’s eyes. Capturing expression, personality and mood in subjects is an important aspect of topside portrait photography (easily done with people), but this is much more difficult with marine life. Lookout for, and be ready to shoot, any interesting or different behavior — a fish or turtle may yawn and open its mouth; a crab or shrimp may raise its claws; a fish may display its pectoral fins.

For more underwater photography tips from pro shooter Alex Mustard, visit the Imaging section of our website.

Christian Loader is a full-time professional photographer for Scubazoo Images. He has worked extensively throughout Southeast Asia as an underwater videographer and photographer for Scubazoo since 2007, and lives in Kota Kinabalu, Sabah, Malaysian Borneo.