> Conclusion: The rainwater/limestone powder theory
> doesn’t work. Just like the „black and white
> The problem with you people is, you simply don’t
> want it to be there, but it is really there.
The idea that the "waterfall" is an illusion caused somehow by monochrome photography is frankly codswallop.
Three photos taken from three viewing angles. The specular highlight(flash reflection area) rendered in different places as one would expect, the relative angle of incidence and refectance having changed due to the camera and flash being re-positioned.
The "waterfall" staining being present and consistent in all three photographs.
May I suggest that it is less obvious in colour photographs as the popular transition from monochrome photography to colour photography took place during the 1960's.