I also like this one best. For me, the collodion images that seem to work best are those in which most of the image is in the darkest tones and there is less midtone and high tone. I seem to like the collodion images that have detail just emerging from the deeper tones. I guess that is because we see a lot of posterization in the midtones and highlights, right? Don't they tend to clump together in collodion? For example, the other portrait of Tim looks kind of posterized to me... not enough mid/hight-tone separation for my taste. This one is wonderful though!