What is video passthrough in AR and VR?
Video passthrough shows the wearer a camera view of the surroundings on displays. Optical see-through instead lets the wearer see the surroundings directly through transparent optics. The difference is how the real-world image reaches the eyes.
The camera view becomes part of the pipeline
Passthrough involves capture, processing and display before the wearer sees the scene. Distinguish that pipeline from the rendering of virtual objects, because both contribute to the complete view. A compelling digital overlay does not, on its own, tell you how the underlying camera view behaves.
Imagine raising a hand in front of the device. In optical see-through you see the hand directly. In video passthrough you see the camera's representation of it. This is a useful first distinction when comparing headsets and glasses, before discussing field of view, application support or spatial tracking.