P3D Specular highlights

["John Goodman" <jgood@xxxxxxxx>]

I've noticed that some very bright specular highlights in 
slides appear larger and fuzzier than in reality. I thought 
this might be due to a lens effect, but I see it with any 
camera and film. A dramatic illustration came about with an 
iron fence having arrow shaped tips in far middle distance 
in a line parallel to the camera, in bright sun. Of course the 
tips are all the same size, but their size appears 
progressively larger as the glinting reflection gets brighter, 
toward the side of the view.

Halation is a word I'm familiar with, but I thought the film 
backing took care of this. What are the contributing factors 
if that is what this is? Do different films show radically 
different sensitivity to this phenomenon? Does lens quality 
have much to do with it? In the above case, there was no 
retinal rivalry. Thanks for any information!

JG