Greetings fellow researchers:

We our utilizing the Vicon 370 3D motion analysis system to acquire kinematic
data and have recently encountered a problem known as a "black hole".
While each camera (our system has six) can see a given marker, this marker is
"lost" in the reconstruction process. I don't know the details,
but apparently it has to do with the cancellation of intersecting rays in the
reconstruction algorithm. I was wondering if anyone had encountered a similar
problem and perhaps could offer some insight.

Thank you,

Judy Redling
Motion Analysis Laboratory
Kessler Institute for Rehabilitation
West Orange, N.J.
tel: 201-731-3900, xx2219
fax: 201-243-6984