What you're saying makes sense to me. I have definitely determined that I can affect the density of the highlights through normal time / agitation changes in Bath A. (So far I have kept the times for Bath A and Bath B the same for simplicity sake.)
I have only processed two rolls of N+ thus far. With the first roll, all I changed was the amount of Sodium Metaborate in Bath B. I did not see much of a contrast increase over what I metered. No prints yet, but the highlight densities are not what I would normally expect from N+ development.
With the second roll I increased the Sodium Metaborate AND increased the development time by 1 minute. This roll looked like a normal N roll, so there was a definite increase in the highlight density from what my meter showed.
This would seem to support you theory. (Though I do not have a densitometer I believe I have enough experience to judge whether or not there was an increase in the highlight densities based on how I metered the scenes, at least with a non-staining negative.)
For my next N+ roll I plan to use the the normal amount of Sodium Metaborate in bath B and simply increase the time by 1 minute. If that works, the next time I feel I need a lot of expansion I will not only increase the time by one minute but agitate more frequently as well.
When next I encounter a scene which requires serious N- development I will try decreasing the time, and for the second roll decreasing the time as well as the agitation in Bath A.
I will say that there does indeed seem to be some compensating effect in the normal procedure, as I mentioned I have exposed moderate N- scenes on the same roll as N scenes and moderate N+ scenes and come away with negatives that print more easily that when I did this with other developers (which happened frequently with my Rolleiflex T as there is no ability to change backs).
As far as the Pre-Soak...
My main reason for doing a short presoak is to remove the AH dye. I have been running 8 rolls through 1 liter of Bath A (Thornton suggested 15 was possible so I thought I'd be conservative. It's pretty cheap stuff even at 8 rolls). 8 rolls worth of AH dye in the developer would be quite messy. I'm not sure if that would matter but it would certainly make it difficult for me to see if there were particles or foreign objects in the developer. I let the negatives drain off water for 30 seconds and shake them a bit during that time. Also, my N time for HP5+ has been 5 minutes so I assumed that in that amount of time there would be plenty of chemistry absorbed by the emulsion.
Last edited by Shawn Dougherty; 08-19-2013 at 10:08 PM. Click to view previous post history.