We are investing the motion characteristics using the highspeed camera system which can photograph from multi-directions.
Three synchronized highspeed cameras photograph a butterfly in the direction of x, y, and z. For example, DITECT D3 has 1280*1024 resolution and 1000 fps.
The wing position, velocity, angle, and angular velocity are calculated by the image processing. Unlike a dragonfly, a butterfly has overlapped fore-and hind-wings and its wings are opacity. Thus, the motion analysis needs high technology.
Takeoff of swallowtail butterfly (by Sato the 3rd):
Flapping frequency: 10Hz
Mass: 0.5 g
Wingspan: 10 cm
Frame per second: 1000 (?)
Pressure contour during roll turn (by Shindo):
Red is the positive pressure and blue is the negative pressure. The difference between the positive and negative pressures on the wing generates the lift, and moreover the difference between the left and right lifts creates the roll moment.