Marker Velocity setup

Camera movement can look like bar movement. Keep the camera completely fixed after calibration.

Set up

Select one, two or three markers. One marker remains the default.
Print the required IDs at Actual size / 100%: ID 0 for one marker, IDs 0–1 for two, or IDs 0–2 for three. Use the same size for every marker.
Mount every marker flat and securely on the same moving bar or plate assembly. Space them so the athlete, bar and rack are unlikely to hide all of them together.
Use a rigid tripod, strong even light and the normal rear camera. Keep the full bar path visible.
Film square-on. Depth movement and changing plate angle reduce accuracy.

Calibrate and track

Choose the printed marker size and marker count.
Find every required marker in one frame, then tap the true centre of the bar sleeve.
Keep the camera fixed and start the set, or choose an uploaded-video analysis range. Tracking continues while at least one calibrated marker remains usable.

Results

For cleans, clean and jerks, and snatches, velocity and displacement cover the upward pull from the starting position to peak bar height. Turnover, catch and recovery are excluded; the jerk is also excluded from clean-and-jerk results. Other lifts use the concentric phase. Peak and propulsive velocity are camera-derived estimates. Diagnostics contain measurements and errors, never raw video.