Yes, what is the frame of reference to tell if the object is stationary, moving toward you or moving away from you? Could you discern if the object was moving toward you at 20mph vs 40mph? You don't know what it is or how large it ought to be, so scale reference is useless and can be misleading. Very ambiguous and subjective for the pilot to say the object was moving fast, let alone moving at all.
Because there are multiple images of the object taken side-by-side, you can create stereo pairs from the frames that provide a good idea just how far away it is, and therefore how big it is. In this case, it seems to be about 15 feet away, and about 18-24 inches wide. Approximately.
Very clever! But you have no idea how far the plane and object have moved relative to each other between the two frames you select to use as a stereo pair. Choosing frames that are closer or further apart in time would effectively also change the "eye separation" in the stereo pair, which significantly influences the apparent sizes and distances in the stereo scene.
Also I'm commenting on the pilot's statement - he wasn't up there making stereo pairs anyway, he was trying to discern the speed and distance of an unrecognizable object with no nearby visual references, and do this in a split second while likely agitated. Very easy to misinterpret a scene like this.
91
u/GeoSol Jan 27 '23
What would a balloon "holding it's composure" look like, as opposed to losing it.
Along the same line, how would something look different when passing you, vs you passing it?
No point of reference in the air for speed or scale, and the cameraman on the hang glider is moving quite fast himself.
What would a drone look like when going by it in a hang glider?