Light Trails of the "Grand Battement"
Iris Griffin
Award: Top 100
School: sleepy hollow high school
Teacher: leila madani
Category: Contrived
Photo #21092
Light Trails of the "Grand Battement"
This long-exposure photograph captures a dancer performing a "grand battement, " or "big kick." Taken in a dark studio with LED lights attached to her foot, the exposure tracks her leg's path from takeoff to peak height.
The leg rotates around the hip joint axis. While all points share the same angular speed, their linear speeds differ. Because linear speed depends on the radius (v = ω r), the toe moves faster than the heel. The light trails function like a physics motion dot diagram. The purple dots (attached to the toe) are spaced farther apart than the pink dots (attached to the heel), visually proving the toe's higher linear speed.
Furthermore, tracking a single light trail reveals excellent technical control over the kick's changing speed. The dots are clustered tightly at the bottom and top of the arc, demonstrating the slower, controlled acceleration from the floor and suspension at the peak. In contrast, the dots spread far apart in the middle, capturing the explosive, maximum speed of the kick. At the very peak, the purple trail (attached to the toe) vanishes because the dancer rotates her foot outward to maintain proper ballet turnout, avoiding "sickling" (turning in).
While the measured angular displacement is about 123°, an ideal ballet line approaches 180° for maximum visual extension. Finally, clear floor reflections reveal a smooth, low-friction surface. To prevent slipping on such floors, dancers use rosin (a pine resin) to increase traction, though specialized Marley flooring provides the ideal balance of grip and glide.
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