I haven't figured out how PS lens blur can do that sharp middle section. The only way I've worked on changing the actual depth of focus is by changing the gamma of the depth pass (copied into the alpha layer), which means some going back and forth (try lens blur, no good, undo, change alpha layer, redo, etc). If anyone can explain how a sharp middle section can easily! be done, I'd appreciate it.
And sorry for temporarily hijacking your thread, Archonforest.