420 Dive Log Australasia OCTOBER 2026

visibility, cloud cover, the position of the sun and the direction in which I am photographing all influence the result. I therefore fine-tune the underwater presets through the camera’s A and G white-balance compensation controls. The A axis moves between amber and blue. Increasing A adds warmth, while reducing it moves the image towards blue. The G axis moves between green and magenta. Increasing G strengthens green, while reducing it adds magenta and counteracts a green cast. In shallow or relatively neutral water, A +1 and G –1 provide a gentle correction. In clear blue water, A +2 and G –1 add more warmth without applying a strong magenta shift. For colder looking or deeper blue water, I may begin at A +3 and G –1, although that can become too warm near the surface. In distinctly green water, A +2 and G –3 apply a much stronger magenta correction. Top: I was using a white focus light, which attracted a cloud of tiny planktonic organisms and other small marine life, completely obscuring the subject. Bottom: This time I used a red focus light, which was far less attractive to the surrounding plankton and allowed me to photograph this dumpling squid clearly.

These values are starting points, not recipes. A setting that produces natural colour in Melbourne’s green water may create an excessive magenta cast in clear tropical water. Even a one-step change on either axis can make a noticeable difference to a JPEG straight from the camera. White balance cannot recover colour that is no longer present in the available light. At greater depths, or when too much water separates the camera and subject, increasingly strong correction may only create unnatural colour and additional noise. That is when artificial light becomes necessary rather than trying to solve everything through white balance. The TG-6 and TG-7 can record JPEG, RAW or both simultaneously. RAW provides much greater freedom to adjust white balance in post production because the setting is not permanently baked into the file. Even then, I prefer to get the colour as close as possible in Top: Taken at around 10 metres using a wide-angle lens and a single strobe. Bottom: Taken at a similar depth, also using just one strobe, but at very close range without the wide-angle lens. Here, I used the TG-6 at its widest native focal length.

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DIVE LOG Australasia #420 October’ 26

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