Friendly Grouper

Going through my photo library for a project last week, I came across this image of a black grouper (Mycteroperca bonaci) from my trip last year aboard the M/V Shear Water in the Bahamas. Much to my dismay, I was never able to find time to write about the enjoyable and educational trip, as I had back-to-back commitments lined up for some time thereafter.
Anyway, this was one of the non-shark encounters during the trip. This fish, along with another, seemed to "own" a section of the reef. They patrolled the area, swimming in a relatively predictable pattern. All I had to do was find the right spot to frame the image and wait. Sure enough, the big grouper came over to take a nice and friendly as could be.

Besides picking the optimal location, the challenge photographically was to light the subject in a way to maximise visual impact. In this case, the key was to set the EV (exposure value) to be slightly underexposed, and to use a main light (not diffused, targeted) off to the left, slightly below and behind me to emphasise the line of the fish's face. Aiming the light at an angle to avoid lighting the background reef was critical. If I had lit the reef behind the fish, there would have been a lot of clutter, which would detract from the main subject.

I used a fill light, diffused, set about 1.5 stops lower than the key light, above and slightly to the left-of-center to provide overall fill, again aiming the strobe to avoid bringing out the background.

Photo data: EOS 5D, f7.1, 1/125, ISO160, 17-40mm zoom lens, Z-220s x 2.