The kind of image you describe could be printed using
printing out paper since it is "self masking". As the paper
darkens it looses sensitivity so that the shadows are compresed.
A long exposure will cause the highlights to print, even when
blown out in the negative, while preserving the shadow detail.
The same negatives may be extremely difficult to print on
"developing out" paper.
A stain developer, like pyro, can produce a somewhat similar
effect when used with variable density paper because the stain
acts as an image-wise low contrast filter. The effect depends on
the contrast of the paper varying with the color of the exposing
light and does not take place on fixed contrast paper where the
stain just increases the printing density (as opposed to visual
density) of the negative.
On 2/8/2021 4:15 AM, Bill Riley wrote:
I think the term that Richard was referring to is “acutance”, the perception of
image sharpness by the viewer.
My experience is that staining developers greatly improved over all image
acutance. I found that PMK gave me much better definition in darker areas —
tree bark comes to mind.
At the same time, it allowed me to gain more dynamic range in the finished
print. For example, shooting from inside a room with a bright day lite window.
A straight print resulted in a blown out window. However, there was detail in
the window on the negative. I could burn that area in thus increasing the range
in my finished image.
But like everything in photography, there is a trade off. Too much improvement
in local contrast could result in a halo effect between sharp differences in
strong dark to light edges. I’m told that that was the result of silver
migration from dense to less dense intersections.
Regards,
Bill Riley
On Feb 8, 2021, at 3:28 AM, Luis Miguel Castañeda <octabod@xxxxxxxxx> wrote:==========================================================================================================To
First of all: I have no direct experience with pyrocat-HD itself, but had some
with a few catechol-based developers and other staining developers, like tanol,
finol, and Thornton's dixactol.
I guess none of those are in a different ballpark if not very close brothers;
even some claimed to be the same formulation under a different name.
My experience on staining (either catechol or pyro) is :
- Catechol stain is faint.
- Different emulsions colors differently, with several degrees of intensity,
no matter what kind of agitation you use.
- Most stain color seems to be washed out during fixing and washing.
I've found that the advice of using an alkaline sodium thiosulfate-based fixer
(as TF2) without sodium sulfite keeps as much stain as you will get. I doesn't
keep beyond the day, so I do prepare it just before use. I don't know the
chemistry behind that, it's only a empirical observation after following advice.
- Without carriyng proper testing which needs more equipment and methods than
most of us have, it's almost impossible to tell apart what is stain by
reduction and what is gelatin toning (inside the picture, of course).
As final note, my lab gets water in a wide range of temperatures depending the
season, so I standarized in 24C processing (75F), as it's easier to heat in
winter than cool down during the long summer. It may take its role in staining,
can't tell as I'm using this temperature as standard for a very long time.
my 2c.
On Sunday, February 07 2021, 23:01:22, Tim Daneliuk wrote:--
Tri-X (at least TXT - how many versions of Tri-X have there been?
Many, methinks.) stains most.
Neither APX 100 or FP4+ stain anywhere near as much.
Compare the black-and-white photographs of Ansel Adams, Edward Weston and
Irving Penn, with color or digital. It's the difference between art and mere
representation.
--- Yvon Chouinard
=============================================================================================================
To unsubscribe from this list, go to www.freelists.org and logon to your
account (the same e-mail address and password you set-up when you subscribed,)
and unsubscribe from there.
unsubscribe from this list, go to www.freelists.org and logon to your account
(the same e-mail address and password you set-up when you subscribed,) and
unsubscribe from there.
