You are absolutely right!! Pyro does the opposite of "flattening" the
negative relative to UV light. I've been touting this for years now. I
am confident that your "new" platinum negatives will print very well in
silver, if you choose to do so.
Really, the only drawback of using Pyro for platinum negatives is
somewhat longer print exposure times. And even that is not significant.
Most of my negatives print in the 8 to 12 minute range.
As far as densitometer readings, they will definitely be affected. You
really need a color densitometer to read Pyro negs properly. I've never
done it, but I believe you would use the densitometer on the blue
channel (?). Gordon Hutchins' "Book of Pyro" explains the procedure.
> > 1. What sort of ranges are we talking about here ?
> >
> > 2. Surely the disadvantage of the stain is that it flattens the
> negative.
>
> The pyro stain *increases contrast* for Pt/Pd printing or other UV
> sensitive emulsions because the stain, which is proportional to silver
> density, increases the effective density of the highlights when
> printing
> by UV light. My recent first test of PMK pyro using HP5+ gave me a
> much
> higher effective contrast than any standard development of that film
> has
> done, giving adequate contrast for a Ziatype with no contrasting
> agent.
> That is equivalent to a range of about 1.9 or 2.0 printing from negs
> souped in "regular" non-staining developers. I'm not sure how the
> stain
> density will affect densitometer readings, and haven't a densitometer
> handy right now to check. But it prints in platinum like a 2.0 neg. I
> haven't yet had a chance to see whether it will also print at a much
> lower contrast on standard silver paper, but it looks promising just
> eyeballing the negs.---Carl
>