Leif,
In the last few days I evaluated CA comparatively between four of my own binoculars. The weather in my area lent itself to doing this. My primary reason was to determine, introspectively, how I would react (mentally), rather than analyzing the visual details. The long and short of it is that behaviorally I did things quite differently than I would normally when using binoculars. Essentially, this required that I manipuate instrument pointing, move my eyes, and above all attend to the binoculars themselves rather than to the birds. In the process I became keenly aware of the high contrast backlit situations that made the annoying color fringe effects observable. Moreover, once having learned to do it, a "compulsive attention" (another CA) developed that persisted for quite a while, and I became consciously aware that I had developed a localized fascination for the phenomenon.
Anyway, having done this personal experiment for the first (and only) time, I believe that anyone can observe optical CA if they learn the behavior, which all binoculars produce to some extent — differing perhaps in pervasiveness. However, at least for high-end binoculars I'm also convinced that compulsive attention behavior is an integral part of the problem and must be unlearned for the user to be free of it.
Basically, that requires a form of behavior modification. In my case I broke the compulsion (or fasination) by going into the field. When I discovered a family of Eared Grebes in full plumage my attention shifted to the important matters in life, and this was followed by a splendid family of Surf Scoters that sealed the deal.
Of course, this topic has received much discussion on several threads so I apologize for walking on sacred footprints. I wonder how my conclusions square with yours.
Elkcub
