great thread, jim. i too would like to further undstand and control bokeh.
i recently got an old gundlach 5x8 triple convert lens and have been learning how it works. when i focus on a distance of about 15 feet, i can make out the image circle on 8x10. but when i bring the lens forward and focus to about 2-3 feet, i start getting some interesting bokeh in the fall-off around the edges. here is what i got (see attachment)--
View attachment 8181
one thing i have learned from this is that every lens has its own way of doing things and it there is a learning curve. it really does take some testing and practive to "get to know" a lens before you can really take advantage of it. in my newer lenses (nikkor 210, super angulon 90) i dont see any of this. they are very predictable.. i am learning slowly that old glass has more "soul" and personality.