We regularly post short Marine Wildlife Videos an Photographs with a short explanation regarding the subject and the technique used to capture the image.

All videos are made by Olivier Van den Broeck using Light & Motion video lights

and all photographs are by Greet Meulepas unless stated otherwise.

150. Glasseye (Heteropriacanthus cruentatus) (iridescence)

Subject: A Glasseye (Heteropriacanthus cruentatus) moves in and out of the darkness of the nook he calls home. By doing so the scales of the fish bounce back the light of my video lights. This is what is called “iridescence” and it is produced by tiny crystals of guanine that grow on the scales of fish. In combination with cytoplasm (a gelatinous liquid that fills the inside of cells) it creates the typical metallic lustre characteristic for fish.

Technique: The iridescence of the scales acts a bit as a mirror when using video lights. Therefor it is recommend not to set your lights at full power. If you have a “zebra” option on your camera it is wise to turn this feature on so that it can guide you choosing the right settings in order to avoid “burning” parts of your image (burning = overexposed areas in your image, usually complete white with no details visible due to the absence of colours, these areas are irreparable in post-production).