DiXactol Tests

wrote:

You're wasting your time with the troll. It's best to just ignore him.

--




-------------------
Keep working millions on welfare depend on you

Frank, it is kind of entertaining to watch him squirm, but I'm sure
you're right.

Jay

wrote in message
oups.com...

UC wrote:
Is that a staining developer?

If so, stain density will not be seen by VC papers.

Staining developers do not work with VC papers the same
way that
standard developers do. The stain is opaque to blue but
transparent to
green light. I think you're going to find that combo
unsatisfactory.



The above is mostly misinformed and oversimplified, but
partly just
dead wrong. Stain density most certainly is seen by VC
papers. One can
prove it by bleaching all of the silver from a stained
negative with a
ferricyanide bleach, and then printing the remaining stain
image on VC
paper. Staining developers do not work the same way with
any papers as
non-staining developers do. The vast majority of the stain
produced by
any staining developer is seen as neutral density by VC
printing
papers, and acts exactly like silver density, except for
the lack of
grain in the stain density. Please keep in mind that UC
has never used
or tested a staining developer, and has no practical
experience
whatsoever in this area.

Dixactol is a catechol/glycin developer, and as such, I
would expect it
to be rather slow working, and produce an upswept curve,
and a speed
loss with most films. Dixactol Ultra partially addresses
these issues
by adding phenidone, which should increase toe speed and
general
activity, but probably won't alter the upswept curve shape
that is a
signature of glycin developers. If you're interested in
making up a
home-brewed version of Dixactol Ultra, I suggest the
following:


A

distilled water @ 125F 75ml

Sodium sulfite 3g

glycin 2g

catechol 10g

phenidone .2g

sodium metabisulfite 5g

distilled water to 100ml

B

cold, distilled water 75ml

sodium hydroxide 10g

cold, distilled water to 100ml

Dilute 1A:1B:100 water, and develop for 6min/70F


Jay

Have you a published source for sensitometric data on
Glycin developers? If these are your own tests I won't
argue with them but would like to see something. AFAIK
developers other than special purpose ones don't have much
effect on curve shape.


--
---
Richard Knoppow
Los Angeles, CA, USA

Richard Knoppow wrote:

[edited]

wrote in message
The above is mostly misinformed and oversimplified, but partly just
dead wrong. Stain density most certainly is seen by VC papers. One can
prove it by bleaching all of the silver from a stained negative with a
ferricyanide bleach, and then printing the remaining stain image on VC
paper. Staining developers do not work the same way with any papers as
non-staining developers do. The vast majority of the stain produced by
any staining developer is seen as neutral density by VC printing
papers, and acts exactly like silver density, except for the lack of
grain in the stain density. Please keep in mind that UC has never used
or tested a staining developer, and has no practical experience
whatsoever in this area.

Stain images (minus silver) have been printed for decades on VC papers. Most
pyro stains are "yellow", so photographing them with blue filtration with
ortho/pan film or VC paper enhances their apparent contrast; using yellow
filtration masks or hides the effect. Fortuitously the weak stain image requires
high contrast paper grades and "blue" exposure.

Likewise the variable stain density acts as a filter on VC papers, but the
contrast effect is weak except in areas of high density, and there the reduction
is no more that 1 grade. When the PMK formula was first published, I did the
"homework" problem before using the developer for negatives that would be
printed on VC papers.

In an email, Barry had indicated that the developer he was working on had a
neutral colored stain compared to pyro, however brown is nothing more than
desaturated yellow. His comments that the stain reduces contrast confirms that
fact. My PMK stains aren't "green"-yellow nor is there any staining of unexposed
film base after borax treatment. "Problems" seem to be related to the emulsion
or individual techniques.

The reseller advertising hype claiming that catechol is less toxic than
pyrogallol is absolutely false, and that should be evident to anyone who has
read the toxicology literature on phenolic compounds. You don't eat them or
cover your skin with them, though dilute solutions have been used as topical
antimicrobial agents.

I don't care for this type of misrepresentation to sell a product by giving
people a false sense of security. Both pyrogallol and catechol exhibit the same
range of toxic effects from dermatitis to death. The lethal dose of either
compound for human beings is two grams - the same as hydroquinone.

Dixactol is a catechol/glycin developer, and as such, I would expect it
to be rather slow working, and produce an upswept curve, and a speed
loss with most films. Dixactol Ultra partially addresses these issues
by adding phenidone, which should increase toe speed and general
activity, but probably won't alter the upswept curve shape that is a
signature of glycin developers. If you're interested in making up a
home-brewed version of Dixactol Ultra, I suggest the following:


Have you a published source for sensitometric data on
Glycin developers? If these are your own tests I won't
argue with them but would like to see something. AFAIK
developers other than special purpose ones don't have much
effect on curve shape.

I haven't seen that curve shape property ascribed to glycin. Very active
developers like hydroquinone in a relatively low sulfite solution (HC110A or B
compared to D76) and the staining developers may have that property depending
upon the emulsion characteristics. One expects to see it with the old long toe
emulsions formulated for that purpose: PCF, Ektapan, and Tri-X Pro sheet films,
and to a lesser degree with TMY. Phenidone may enhance the toe.

My suspicion has been that in areas of high image density there's a relatively
high concentration of semiquinone intermediates that can induce some infectious
silver development leading to increasing density. Since the reaction kinetics
aren't first order, the effect would increase disproportionately compared to
density. The speculation is supported by the fact that the polymers contributing
the stain density are formed through the same free radical intermediates, so the
semiquinones certainly are there at sufficient levels.

UC wrote:

wrote:


UC wrote:


The problem is you don't understand how VC paper works.

Read and LEARN!


UC,

I know exactly how VC papers work, the problem is that between the two
of us, I'm the only one who knows how staining developers work. Keep
reading, and maybe it will start to make sense.

Jay



"stain density will not be seen by VC papers"

Thornton



Not only are you wrong, but Thornton was wrong as well. I tested this
very thing some time ago in an article for Darkroom and Creative Camera
Techniques. I bleached the silver out of a PMK developed negative and
printed it with VC paper, which one can limit to blue sensitivity quite
easily with filtration. Furthermore, the magenta filtration makes a
greater difference on a PMK negative than it would on an unstained
negative that gives the same print without filtration. Also, it is a
theoretical as well as experimental fact that the yellowish stain of a
PMK negative does not reduce the printing contrast on VC paper as common
myth has it. Certainly, the same stained negative gives higher contrast
on graded paper, but try the following experiment: develop a negative in
a non-staining developer. Print it on both VC and graded paper to get as
nearly as possible the same contrast. Now bleach the silver image with a
rehalogenating bleach such as is used for sepia toning and redevelop it
to completion in a pyro developer. The pyro stain is added to the
original silver image and INCREASES contrast on the VC paper, though not
as much as on the graded paper. Quit arguing from theory over something
you can demonstrate by experiment. Also, the argument from authority is
not as strong as the proof from experiment. I learned that a long time
ago by comparison of aerodynamic theory with experimental fact.

PATRICK GAINER wrote:


Not only are you wrong, but Thornton was wrong as well.

Wrong? The photos are on pages 96 and 97. See for yourself!

I tested this
very thing some time ago in an article for Darkroom and Creative Camera
Techniques. I bleached the silver out of a PMK developed negative and
printed it with VC paper, which one can limit to blue sensitivity quite
easily with filtration.

That makes it like a graded paper, grade 4 or 5! At NORMAL grades
(2-3), there is considerable green passed!

Furthermore, the magenta filtration makes a
greater difference on a PMK negative than it would on an unstained
negative that gives the same print without filtration. Also, it is a
theoretical as well as experimental fact that the yellowish stain of a
PMK negative does not reduce the printing contrast on VC paper as common
myth has it. Certainly, the same stained negative gives higher contrast
on graded paper, but try the following experiment: develop a negative in
a non-staining developer. Print it on both VC and graded paper to get as
nearly as possible the same contrast. Now bleach the silver image with a
rehalogenating bleach such as is used for sepia toning and redevelop it
to completion in a pyro developer. The pyro stain is added to the
original silver image and INCREASES contrast on the VC paper, though not
as much as on the graded paper. Quit arguing from theory over something
you can demonstrate by experiment. Also, the argument from authority is
not as strong as the proof from experiment. I learned that a long time
ago by comparison of aerodynamic theory with experimental fact.

The prints are in the book. It's as plain as day.


--------------090200010106090904020505
Content-Type: text/html
X-Google-AttachSize: 2442

!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
html
head
meta content="text/html;charset=ISO-8859-1" http-equiv="Content-Type"
title/title
/head
body bgcolor="#ffffff" text="#000000"
UC wrote:
blockquote
legroups.com"
type="cite"
pre wrap=""a class="moz-txt-link-abbreviated" "ujazz32@hotmail. com/a wrote:
/pre
blockquote type="cite"
pre wrap=""UC wrote:
/pre
blockquote type="cite"
pre wrap=""The problem is you don't understand how VC paper works.

Read and LEARN!
/pre
/blockquote
pre wrap=""
UC,

I know exactly how VC papers work, the problem is that between the two
of us, I'm the only one who knows how staining developers work. Keep
reading, and maybe it will start to make sense.

Jay
/pre
/blockquote
pre wrap=""!----
"stain density will not be seen by VC papers"

Thornton

/pre
/blockquote
Not only are you wrong, but Thornton was wrong as well. I tested this
very thing some time ago in an article for Darkroom and Creative Camera
Techniques. I bleached the silver out of a PMK developed negative and
printed it with VC paper, which one can limit to blue sensitivity quite
easily with filtration. Furthermore, the magenta filtration makes a
greater difference on a PMK negative than it would on an unstained
negative that gives the same print without filtration. Also, it is a
theoretical as well as experimental fact that the yellowish stain of a
PMK negative does not reduce the printing contrast on VC paper as
common myth has it. Certainly, the same stained negative gives higher
contrast on graded paper, but try the following experiment: develop a
negative in a non-staining developer. Print it on both VC and graded
paper to get as nearly as possible the same contrast. Now bleach the
silver image with a rehalogenating bleach such as is used for sepia
toning and redevelop it to completion in a pyro developer. The pyro
stain is added to the original silver image and INCREASES contrast on
the VC paper, though not as much as on the graded paper. Quit arguing
from theory over something you can demonstrate by experiment. Also, the
argument from authority is not as strong as the proof from experiment.
I learned that a long time ago by comparison of aerodynamic theory with
experimental fact.br
/body
/html

--------------090200010106090904020505--

Barry Thornton once wrote:

"The colour produced by DiXactol is much more consistent across
film types, and gives predictable tonal distribution on graded
and variable contrast papers. The effect of the stain differs,
however, when printing on these different types of paper. On
graded paper the stain acts purely as extra printing density thus
making the negative more contrasty than visual inspection might
suggest. On VC papers the stain also acts to soften contrast
slightly. The colour produced by DiXactol is much more consistent across
film types, and gives predictable tonal distribution on graded
and variable contrast papers. The effect of the stain differs,
however, when printing on these different types of paper. On
graded paper the stain acts purely as extra printing density thus
making the negative more contrasty than visual inspection might
suggest. On VC papers the stain also acts to soften contrast
slightly."


Note that Barry explicitly stated that stain prints on both graded
and VC papers, however on VC papers, there seemed to be a slight
contrast decrease compared to graded paper. Also note, that he
was comparing apples to oranges - two different papers - so
"slight" may be next to nothing.

At times Barry exhibited a bit of bias towards his way of doing
things, but he wasn't a fool or charlatan. It's unfortunate that
his work has been misrepresented to his detriment by a troll.

The stain is INVISIBLE in a large portion of the green wavelengths,
because it PASSES GREEN. Since only a SMALL portion of the components
of the paper react to green light, the effect is MINIMAL, almost
non-existent. That means it's as though it wasn't there!

This SIMPLE, ELEMENTARY PHYSICS! Why you pyro worshipers don;t get it
is because you are ****ing retarded!


Michael Gudzinowicz wrote:
Barry Thornton once wrote:

"The colour produced by DiXactol is much more consistent across
film types, and gives predictable tonal distribution on graded
and variable contrast papers. The effect of the stain differs,
however, when printing on these different types of paper. On
graded paper the stain acts purely as extra printing density thus
making the negative more contrasty than visual inspection might
suggest. On VC papers the stain also acts to soften contrast
slightly. The colour produced by DiXactol is much more consistent across
film types, and gives predictable tonal distribution on graded
and variable contrast papers. The effect of the stain differs,
however, when printing on these different types of paper. On
graded paper the stain acts purely as extra printing density thus
making the negative more contrasty than visual inspection might
suggest. On VC papers the stain also acts to soften contrast
slightly."


Note that Barry explicitly stated that stain prints on both graded
and VC papers, however on VC papers, there seemed to be a slight
contrast decrease compared to graded paper. Also note, that he
was comparing apples to oranges - two different papers - so
"slight" may be next to nothing.

At times Barry exhibited a bit of bias towards his way of doing
things, but he wasn't a fool or charlatan. It's unfortunate that
his work has been misrepresented to his detriment by a troll.

Barry was wrong about one point:

The print is not softer because of the stain. It's softer because the
stain is subtracted from the printig density on VC paper, and what's
left is shorter-scaled than the paper needs to make a full-scale print.
In other words, the silver alone is what prints on the VC paper, and
that is too soft to make the same contrast of print that it would make
on a graded paper.


Michael Gudzinowicz wrote:
Barry Thornton once wrote:

"The colour produced by DiXactol is much more consistent across
film types, and gives predictable tonal distribution on graded
and variable contrast papers. The effect of the stain differs,
however, when printing on these different types of paper. On
graded paper the stain acts purely as extra printing density thus
making the negative more contrasty than visual inspection might
suggest. On VC papers the stain also acts to soften contrast
slightly. The colour produced by DiXactol is much more consistent across
film types, and gives predictable tonal distribution on graded
and variable contrast papers. The effect of the stain differs,
however, when printing on these different types of paper. On
graded paper the stain acts purely as extra printing density thus
making the negative more contrasty than visual inspection might
suggest. On VC papers the stain also acts to soften contrast
slightly."


Note that Barry explicitly stated that stain prints on both graded
and VC papers, however on VC papers, there seemed to be a slight
contrast decrease compared to graded paper. Also note, that he
was comparing apples to oranges - two different papers - so
"slight" may be next to nothing.

At times Barry exhibited a bit of bias towards his way of doing
things, but he wasn't a fool or charlatan. It's unfortunate that
his work has been misrepresented to his detriment by a troll.

I hope you used a surrogate of some sort for those experiments, Patrick.
-Lew
"PATRICK GAINER" wrote in message
...
I learned that a long time ago by comparison of aerodynamic theory with
experimental fact.