Hi gchen,
I’m using a fixed dual-camera rig to record youth football matches and have run into persistent parallax and misalignment at the stitch seam. I haven’t been able to resolve it with the calibration data currently available.
My setup:
- 2x GoPro Hero13 Black cameras mounted on a custom, rigid dual-camera plate. The fixed relative angle and distance between the lenses were designed using GoPro10 technical drawings, and the cameras cannot shift relative to each other.
- Tripod height: 4m, positioned ~1.5 m from the sideline, roughly on the halfway line so both goals are covered
- Recording settings: 5.3K (5312x2988), 25fps, Wide lens; both cameras are confirmed to use identical settings
Calibration used: the community GoPro13.json profile from the “Ghosting between 2 GoPro 13s” thread (14-coefficient rational distortion model, calibrated for 5312x2988).
The problem: even after running Autocalibrate (Positions > Improve Offsets/Improve Angles), the seam remains consistently misaligned in a way that isn’t motion-related. It appears as a torn or doubled edge on objects relatively close to the rig, such as a mid flag or cone a few meters from the tripod, while the distant background (tree line, buildings) aligns well. This looks like classic parallax caused by the physical baseline between the lenses, rather than a blending or encoding issue. We’ve confirmed the issue is absent from each raw source individually and appears only after stitching; it also persists regardless of seam placement.
What I’ve tried without success:
- Using the community GoPro13.json profile as-is
- Repeatedly running Autocalibrate + Improve Angles/Offsets
- Repositioning the seam angle to avoid nearby objects
- Adding manual control points. Mixing near and far correspondence points worsened the overall alignment, suggesting a single homography can’t reconcile both depths.
For comparison, I tested the same footage in Mistika VR (trial) using its optical-flow-based stitcher, which resolved the parallax artefact. This suggests the issue can be fixed with proper per-rig calibration or blending, rather than being an inherent limitation of the footage.
Since there’s no calibration specific to a fixed dual-Hero13 rig with this exact geometry, I’d like to request a custom calibration or guidance on producing one for:
- Camera: GoPro Hero13 Black (2x)
- Resolution: 5.3K (5312x2988)
- FPS: 25
- Lens: Wide
I’m happy to record checkerboard calibration footage at these exact settings and share it via Google Drive or Dropbox if that would help produce or verify a suitable calibration for this rig.
Thanks for maintaining this tool.
Once we resolve the parallax issue, this will be exactly what we need for match-day stitching.
Daniel
