Correction technique illustration.

Illustrations of how image magnification was compensated by using a reference point on the ocean floor. (A) Frame of the C. capillata footage with reference rock highlighted by a red hollow dot in the first frame and red dot in frames j>1. (B) Schematic of magnification correction technique using a background reference point. (C) Schematic of the method used to account for the body rotation about the -axis and -axis. The red dots represent the exumbrella points which meet the 24% criteria. The linear fit was calculated from these exumbrella points.