Hey, back again.
Between renders on another project so I’m trying to get in some KT time to learn it. I’m playing with disintegration effects on photos - sort of a classic for KT, but new toys for me 
I built a quick test and it is going okay but the density parameter seems to be working counter to what I expected so not sure what I’m doing wrong. See links below - by lowering the density (-1 to -3) I would expect the image to be darker and finer, but it’s getting coarser and brighter.
I know the particle count is not high enough for really fine work yet, but I’m still at testing stages. The plan is to port it out to a PRT loader when the dynamics are sorted.
http://screencast.com/t/NzVkMDVjOTg
http://screencast.com/t/OWRkZmE3MjIt
The particles are generated in Pflow, with a position shape operator and a mapping object operator both pointing to a plane. The material in the plfow is a KT material with the image in the Scattering slot and the alpha for the image in the Density slot. There is one Max spotlight illuminating the Pflow.
Is there any reason why it would get coarser with lower density?
Thanks in advance
b