The artifacts of combining the images are seen in the lighter band in the middle of the photograph. Hardware Merging video streams into a single view requires careful engineering and calibration. Instead, the views must be carefully unwarped to remove distortions that exist in the machined parts and camera lenses. Since 2D image processing is much simpler than depth recovery, the cameras are locked down into set positions. A design with faceted mirrors turned out to be easier to construct than a prototype with a curved mirror.
Facets also make the image warping much easier.
The images below show thumbnail images from the Alpha1 modeller.