(meteorobs) Setting Sun Magnitude?

[GeoZay at aol.com]

Geert>>This formula would suggest a correction of 9  magnitudes at 1 degree, 
but 
what's it based on? (Looks  empirical...)<<
 
So we are probably thinking in the range of -18? The photograph I took of  
the sun, just before touching the water, would be about 1 degree. I guess with  
just one more degree lower, I should have seen massive amounts of steam?  :O)
GeoZay