An optical system gets accurate data using reflective markers and high resolution cameras.
Mounting the many reflective markers on each individual joint of the hand so that they stay within the camera's views is difficult.
California freeways have raised reflective markers between lanes, which make an alerting noise when a car crosses them.
They are also used in low reflective markers in a "T" shape.
Now and then, the beam of my headlamp catches a reflective marker high on a trunk, so I guess I'm going the right way.
In the laboratory, reflective markers are attached to the golfer's clothing as well as to the club being assessed.
Numerous attempts have been made to reduce the risk, including reflective markers along the shoulder on each side of the road.
A number of small reflective markers are placed on the thoraco-abdominal surface by hypoallergenic adhesive tape.
Generally they are used to mark the edges of traffic lanes, frequently in conjunction with raised reflective markers.
Four of the seven dancers wear reflective markers.