What Makes Motion Capture "High Speed"?
In the field of motion capture, what does it mean to have the ability to capture at high speed? And, what does the high speed capture allow you to collect? DARI has the answer.
When collecting motion capture data there is a difference between capture speeds. Capture speed is more directly called capture frequency. Capture frequency refers to a camera's shutter speed which is most commonly measured as fractions of a second. For example, if a camera's shutter speed is 60 frames per second (Hz), the camera opens and closes 60 times in one second and takes 60 individual pictures.
For human movement data, if a person moves extremely fast they can produce movement that can be missed by a lower frequency capture speed. At 60Hz a baseball pitcher may move fast enough that sampling data was missed. Research done at ASMI (American Sports Medicine Institute) found that the appropriate speed for capturing one of the fastest movements in the world (a baseball pitch) needs to have a camera capture frequency of +240Hz.
+240Hz is now the accepted line of capture frequency for qualifying as “High Speed” capture.
In the field of motion capture, there are a variety of systems that can collect as low as 30Hz and as high as 500Hz. If you want to capture complex, high velocity, human movement make sure you have the ability to capture at 240Hz or higher.