Hi, Marshall, Thank you very much for taking initiative on this important direction of experimentation.
Eyeballing the attenuation of the Tyndall effect and applying it to the reduction of the particulate fraction needs to take into account the Weber-Fechner law. Ocular perception varies with light intensity proportionally to the logarithm of the latter. The Weber-Fechner relation also explains why astronomers adopted stellar magnitudes that vary with the logarithms of stellar light intensities, instead of the direct proportion. Best regards, Matthew
