Re: shadow density in zone III

From: Etienne Garbaux ^lt;photographeur@softhome.net>
Date: 09/29/05-01:42:16 PM Z
Message-id: <p05210601bf61ed788011@[192.168.1.100]>

Dennis wrote:

> Which brings me to my question. I notice that all the zone system talk
> here references silver paper. Considering this is an alt list, has
> anyone figured out what are the best low end densities to print with
> great detail on a platinum print?

You will receive a number of responses, probably including some conflicting
ones. Pt is a very long (exposure) scale medium, i.e., low contrast. With
pure Pt and no contrast agent, I often use negatives with a DR of 2.8 or
even 3.0 (i.e., image densities from around 0.30 to 3.1 or even 3.3. Pt is
also self-masking to some degree, as Richard noted, which means that it
loses contrast in the shadows -- it has a soft shoulder, in sensitometric
terms (remember that highlights fall on the toe of a paper curve and
shadows fall on the shoulder -- the reverse of a negative). This tends to
give Pt (and Pt/Pd) prints a murky, muddy look, in my experience (I have
noticed this in numerous exhibitions by "name brand" photographers, as well
as in my own work). This can be exacerbated if one lets the shadows fall
on the toe of the film curve, which also flattens the shadows.

So: avoid films that have an "all toe" characteristic (e.g., Tri-X Pro),
and make sure that the darkest values where you want some texture fall on
the linear portion of the film curve. Ideally, one would like a film that
has an "all shoulder" characteristic -- it would leap up from the base
density, getting less and less sensitive with increasing exposure.
However, I am not aware of any such product. In the bad old days, I would
overexpose a bit, use a superproportional reducer to cut the high negative
densities without affecting the shadows much, then intensify with a
sub-proportional intensifier to increase shadow contrast without affecting
the highlights much. (Whew! Makes me tired just describing it.) For
those who make enlarged digital negatives, all of this can be accomplished
much more easily using curves or levels in PhotoShop.

Best regards,

etienne
Received on Thu Sep 29 13:42:40 2005

This archive was generated by hypermail 2.1.8 : 10/18/05-01:13:02 PM Z CST