Thank you Matt. I neglected the link in my last post, which is the same Ilford publication. At this moment and for the next few nights I am making my tests. Some with negatives, some with a 21 step Stouffers. This post is just an aside in the meantime to ponder that the price of the 67 Dichro bulb is something to consider in this attempt to switch from the standard Beseler 67C head to the color head. I wonder how long these dichro head bulbs last and if they can take thermal shock well from repeated on-off cycling like this. For instance, flip a slide or movie projector on and off a few times and you'll blow the bulb. I wonder if these dichro bulbs can take the punishment. At any rate, maybe I'd better order a spare or 2. Setting up the kitchen to do darkroom and then having a dead bulb would be annoying.