Side-by-side comparison places two videos next to each other, or one above the other, so they can be reviewed together. It is commonly used to compare an athlete with an earlier session, the left and right sides of the body, two repetitions under different conditions, or an athlete and a model performance.
Unlike overlay comparison, which places one clip on top of another, side-by-side views keep each video separate. This keeps both clips easy to read, though small differences in position can be harder to see than in an overlay.
Synchronization
The clips are usually aligned at a shared event, such as foot contact, the top of the backswing, or ball release, so the same phase appears at the same time on both sides. If the clips were recorded at different frame rates, synchronized playback needs to account for that difference so timing is not misrepresented.
Practical Tips
- Record both clips from the same camera angle, height, and distance
- Use the same frame rate when timing will be compared
- Choose a clearly visible sync event close to the phase being studied
- Mirror one clip when comparing left- and right-handed or left- and right-side performers
- Frame the subject at a similar size in both clips
Common Pitfalls
Differences in camera position can create apparent technique differences through perspective error. A difference in zoom can make one athlete look larger or farther from an object. Comparisons with another person are also limited by differences in body size, proportions, skill level, and task conditions, so a model performance should guide observation rather than be copied exactly.
Timing drift is another issue: two clips synchronized at one event may separate later in the movement simply because the athletes move at different speeds. Re-syncing at a later event, or comparing positions rather than elapsed time, can help.
KineVision supports side-by-side and top-and-bottom comparison layouts with synchronized playback, and drawings can be added to either clip. Side-by-side comparison is most informative when the recording setup is consistent and the comparison targets one specific question.