PHOTO ANALYSIS

1 TREAD SOFTLY A good strategy when photographing skittish marine life is to prepare your kit before approaching. While still two metres away, I adjusted the position of my flashes to ensure that they would illuminate the area directly in front, and dialled in my exposure settings. Now prepared, I glided into the zone, holding my breath (exhaling is surprisingly noisy), and took a test shot. I then backed up to exhale and preview the image before repeating the process.

2 ZOOM IN Macro lenses capable of life-size magnification at minimal focusing distance are ideal for textures and patterns. Next time I shoot a giant clam, I’ll fit an external wet diopter (a set of lenses that shortens the focusing distance of a macro lens) onto the camera housing, to increase magnification to twice life-size.

3 POP THE COLOUR Scenes with high dynamic range (here, both neon blue highlights and rich dark tones) require careful exposure. To avoid overexposing the blues, I reduced my flash and checked my histograms to ensure I wasn't blowing out the highlights. I used RAW format, which meant I could bring out the detail in the shadows in post-processing.

4 SHARP STRIPES The plane of focus is very shallow when working at high magnification close to your subject. I used an aperture of f/22 to maximize depth of field and keep as many stripes as possible in sharp focus. For a fish portrait from 50cm I’d use f/8 to separate subject from background.

5 IN THE TWIST There’s rarely a ‘correct’ orientation with abstract underwater shots. I preferred this horizontal, with the black hole of the animal’s siphon off-centre.