If I remember right… its been more than a few years since my M6…
The white out problem and the M6 happened when a strong light source was at an angle off to the right of the camera. Just the way the light entered to light gathering window I thought maybe at the time. It didn't happen often, but when it did moving my eye around to 'center' didn't help. I had to either change camera positions (which changed the photograph of course), or guess the focus distance.
As everyone knows the M3 and its unique M finder is the best for its clean rangefinder patch without white-out. All others can suffer to some degree with the late M4-2, M4-P, and M6 having the most problems (no condenser lens). The .85 suffers the worse, and the .58 best for no white out. And my personal best (non-M3) is the M5. For whatever reasons it was the least flare/white-out rangefinder patch of any M-series [again non-M3] I've had.
So now we can get on with the really important discussion; which is worst/better, an unlucky idiot, or a lucky idiot :angel: