Peter
The point at issue is the extent to which different processes, given the
differing ways in which they react to to diifering ranges of brightness, will
accept information from the negative. A s/g print will accept around three three
stops and a pt/pd print around seven and a carbon around eight : in other words
four stops on either side of the mid point. It is in these circumstances that
the manipulations needed to get the necessary information into the three stops
range of a silver gelatine negative, which is what the zone system is about,
become otiose.
Given that the range of a step wedge can be printed onto pt/pd paper, could you
please explain how the reflected density range of the print is relevant to the
discussion. Does not the fact that that density range is communicated in
perceivable differences in tone from the negative to the paper imply that this
will happen whether the negative is an image or a step wedge. And does this not
confirm the point as to the zone system in the previous paragraph. Incidentally
nobody is suggesting that extreme scale negatives are necessary for platinum
printing: the point is that they are capable of that scale.
Sometimes it is a little difficult for us ordinary mortals to understand these
messages from from the gods.
The point as to the amount of light that can be perceived at one time has
important aesthetic implications. I am surprised that you find it futile. I
suggest that your own eyes will confirm that although you may be able to
perceive shadow detail after allowing them to adjust to the light, if you are
looking at a contrasty scene, then you will not be able to see into the shadows
without shielding you eyes from the bright light. As this is a truism, I would
agree that futher discussion on this point is futile.
As to the printed authorities, one infers that some people are inferring
different things from them. It is important to apply the information in a manner
appropriate to the context.
One suspects that a closer reading of the postings would lead to your not
treating them so dismissively.
Terry