So I received my fourth body and did a test.....
Oh nooo, some specs which did show the "halo effect".....
Well, at leat no strings of stains but the "halo"effect was one of the key features of the stain.... So here I was
again....
Someone said "try cleaning anyway" and I did... While I did find that my blower was very dirty (many new specs) the original specs were gone and many of the new specs also had the halo....
So I think the halo effect is NOT typical of the stains but may occur with certain dust specs as well... Maybe we can eliminate quite a few stained bodies after all....
Diffraction around dust particles?? maybe in combination with the pixel density??