Drivers, Windshields and HUD signal and noise.
Cars have dark dashes to limit dash reflection ghosts in the windshield. All cars have light conditions that cause visible reflections of dash. Chrome, vents, contrasting stitching and shadows from multilevel dashes and even varying dash surface textures project project.
On the small HUD projector on my son’s S class MB, the only reflection on the windshield was the HUD projected data. I call this a noticeable ‘signal’ imposed on the signals of the relevant view of the road and its surroundings. There was no other visual from the HUD. No ‘noise’.
In the early Dream Edition iteration of HUD there I saw a light white ‘greyed’ rectangle reflection ie a very consistent reflection of the larger projector surface. I assume ( usually not a good thing) that physical warping distorted this rectangle into the ‘orb ghosts’ that others saw.
On a recent build Gravity with HUD (I did not sit in but looked at through a n open side window) It was clear that the frame of the HUD was very clear sharply and it seemed unavoidably projected on the windshield. I could not tell if the screen projection partially ‘greyed’ the large rectangular shape inside that frame.
I categorized all of this, the greyed rectangle and even the visible frame as visual ‘noise’. Noise that your brain ‘filters’.
Interested in learning just how much secondary reflection persists in the recently delivered HUDs.
Note: a common Neurosensory phenomena for humans, signal to noise filtering declines as we age. (that is the reason many hearing aids are abandoned to a life in the patient’s dresser draw.)
And yes, I am old ( but have not yet retired my hearing aids to li in a drawer).
