Subject: A school of Bluestripe Snappers (Lutjanus kasmira) face a slight current next to the shallow wrecks of “Emily and Water Lilly” in Mauritius. A colony of soft coral (Nephtheidae) grows on one of the vessels’ railing. Each bush of this coral species is a colony of sessile animals (sessile = fixed to the substrate).
Technique: This is a good example of composition combined with depth of field; combining the soft coral bush on the foreground and the schooling snappers on the background. In order to have both subjects focused it is necessary to film such a scene with a small aperture/high f-stop resulting in a great depth of field. By doing so you reduce the amount of light entering the camera, therefor a scene like this one is best filmed in shallow water on a sunny day where there is a lot of natural light available.