Density Range

tomf2468@pipeline.com
Tue, 25 Jun 1996 01:36:35 GMT

My goodness people, I knew a few zone fanatics considered it a religion,
but I didn t know so many non zone fanatics considered there step tables /
working methods a religion!! Seeing as I have only had one response out of
30 or 40 that had ANYTHING to do with my original question (rather than the
words I used) (and this despite trying very hard to include zone terms,
descriptive terms, and density / step wedge terms for each and every
example): I thought I d report back on what I have discovered.

My original question was WHAT IS THE STANDARD METHOD OF DETERMINING THE
DENSITY RANGE OF A NEGATIVE . I know some have suggested that this isn t
the proper forum for discussing the zone system, but alternative process
workers (more than others) have to say this process needs a 1.5 density
unit negative, this process needs.... .

There seems to be NO standard method!!! All of the experts disagree, and
often contradict themselves! Zone 9 minus one 1, zone 8 minus zone 2, zone
8 minus zone 1, and zone 8 minus zone 3 are all suggested! Let us agree on
some terms for the length of this discussion. If we print a negative, such
that maximum black is just obtained through the least dense portion
possible in an in camera negative then: zone 0 will be considered the
negative value (thin) at or near enough to appear as D-Max in a print.
Zone 1 will be the negative value which will print as the first perceptible
value lighter than D-Max and will contain no detail (only tone). Zone 2
will be the thinnest negative value that will print with some (limited )
detail. Zone 8 will be the negative value that will print as light (white)
as possible while still holding some (limited) details. Zone 9 will be
the negative value that will print as a tone (only, no detail) just
slightly darker than paper base.

I realize I ve just run into one of the zone system s limitation in
alternative processes. The above descriptions work great for silver
gelatin, but platinum can have quite a few tones below and above the
threshold of detail(zones 8 and 2), while cyanotype doesn't really have
any! But we are living in a silver gelatin world, so please read on and
hear me out (and please humor me, value the descriptions of zone 2 and zone
8, the thresholds of detail).

David Scopick in The Gum Bichromate Book, edition #2 indicates (on page
#95) that density range is measured from the minimum to maximum PRINTABLE
densities....the extreme areas of the negative we want to maintain detail
in the print... (emphasis mine, or Zone 8 minus Zone 2).

Charles Swedlund in Photography (Page 278, my college textbook) indicates
it as zone 8 minus zone 1 ( determine which step represents step 1- that is
the first perceptible tone lighter than black...determine which step
represents zone 8, that is the lightest value that holds detail...subtract
the density reading of zone 1 from the reading of zone 8... ).

Phil Davis in Darkroom and Creative Camera Magazine (Nov/Dec 1992, Pg 53)
suggests a zone 8 minus zone 2 approach in one paragraph, then two
paragraphs later suggests zone 8 minus zone 1.

William Crawford in Keepers of the Light (pg 119) first states that The
density range of a negative is the difference between the most and least
dense areas on the negative from which you will print detail... . But in
the nest section states ...In the print this will correspond to the first
highlight tone just perceptively darker than the white of the paper...the
shadow value just perceptively lighter than the maximum density (the
blackest black) of which the paper is capable... Sounds like he first
suggests zone 8 minus zone 2, then suggests zone 9 minus zone 1!!

Dick Arentz in An Outline for Platinum and Palladium Printing (which
saved my life when I started Platinum printing) ( a great intro book)
suggests (on page 48) what is basically zone 8 minus zone 3.

Me, I m sticking with my original zone 8 minus zone 2 or edges of white
detail minus edge of black detail method. It doesn t disagree with more
experts than any other method, and is by far the most applicable to
alternative processes.

P.S. Looks like my teaching job (which started this question) fell
through. The school descided that alternative process s was too
advanced a subject !?!?!?

tomf2468@usa.pipeline.com (Tom Ferguson)