I've just run a quick set of tests
method 3 interval 1 samples 15 - 100ppm
sample spacing has no effect on the hard edges and paterns in the clouds
method 3 interval 2 samples 15 - 31ppm
hard edged patterns and artifacts dissapear
method 2
lousy colour 51 ppm
method 1 10 ppm
very spotty and broken texture
Mick
