I've been studying lens flares and the various phenomena that occur alongside the reflected "ghosts" that are most commonly associated with them. Of particular interest are the red rings that surround the light sources in shots like this one from ET:
And this shot from Blade Runner:
Can anyone explain what causes these rings, and what (if any) their proper name would be?
My theory is that they are some kind of diffusion effect, possibly caused by smoke being in the shot, as opposed to being a result of a physical property of the lens itself. It also seems to occur when the light source is pointing directly at the camera, with the size of the light source contributing to the softness.
As for the colour, they usually manifest as red, even if the light source appears to be completely white, as in this image from Apocalypse Now:
Any insights would be very helpful, thanks.