Pyro Developers Question.

[Darkroom User]

Is there any advantage or quality difference to using a pyro developer
instead of a normal developer such as D-76 or Xtol?
Developers like Pyrocat-HD, WD2D and PMK get mentioned a lot on the
internet photo sites.

--
Darkroom User

[Richard Knoppow]

"Darkroom User" <Darkroom.U...@photobanter.com>
wrote in message
news:Darkroom.U...@photobanter.com...

Boy, have you opened a can of worms here:-) Pyro was
the first organic developer discovered and applied c.1860.
Previous developers were inorganic and nowhere near as
efficient. Pyro remained a favorite for the next fifty years
but was eventually supplanted by developers employing a
combination of Metol (AKA Kodak Elon and a bunch of other
names) and hydroquinone. These two in combination can make a
very wide varity of developers.
Pyro, in the right sort of formula produces a stain
image along with the silver one. The stain image is usually
a yellow or greenish brown. It increases the effective
printing density when the printing material is sensitive
only to blue light. Pyro became popular when it was
discovered that the stain image would act as a contrast mask
when films were printed on variable contrast paper, tending
to lower the contrast of the highlights. This was considered
desirable because some modern fils, tabular grain ones like
Kodak T-max for instance, can produce extremely high maximum
densities. Because the traditional Pyro developers tended to
be somewhat grainy some more modern ones were devised. PMK
in particular has become popular. However there may be
problems with it, for one thing the books on photographic
chemistry warn that borax is not compatible with Pyro and
should not be used in Pyro developers. PMK uses "Kodalk",
Kodak's trade name for sodium tetraborate, a borax compound.
I've seen several explanations of why this is OK in this
particular formula.
Traditional Pyro developers are mixed from two or three
stock solutions. This is because the most Pyro developers
are vulnerable to oxidation from the air and are not long
lived when mixed. When Pyro was the principle developing
agent a great deal of work was put into devising
_non-staining_ formulas. This is because the effect of the
stain on printing density is not easily predictable and it
was found in motion picture practice that obtaining
consistent results was difficult. When D-76 was introduced
in 1926 it very rapidly displaced all other developers for
motion picture negative processing. This was partly because
it produced fine grain negatives but also because it was
more consistent and controlable than previously used
developers.
Pyro has a couple of advantages especially for tray use:
while it is itself rapidly oxidized it does not produce
aerial fog, secondly, its a fairly good desensitizer so is
advantageous when developing by inspection.
The short life was addressed in some two part forumulas
which included Metol. In these developers the Metol is
present mainly to preserve the Pyro although it also
functions as a developing agent. Kodak D-7 is an example.
The three part developer, often called ABC developer,
evolved over the years to the point where the published
formulas were all the same. Kodak D-1 is a classical ABC
developer. These are still quite satisfactory but are
probably a bit grainy for 35mm film.
Some early formulas used acetone as an intermediate for
generating carbonate (actually hydroxide) in solution.
Because the acetone is volitile these developers tend to be
inconsistent and are the main reason that Pyro got the
reputation for being inconsistent. The later formulas using
sodium carbonate are much more satisfactory but one still
has the problem of determining actual printing density and
contrast due to the stain image.
BTW, the stain is composed of a humic acid pigment, not
a dye, and is probably more permanent than the silver image.
Pyro will also work as a warm tone print developer but the
color may not always be a desirable one.
I collected a bunch of Pyro formulas which someone
kindly posted to their web site. It appears as a PDF at:
<http://www.nonmonotonic.net/Photochemistry/Richard%20Knoppow/Pyro_Developers.pdf>
There are some good articles on Pyro developers on the
web:
http://unblinkingeye.com/Articles/PCat/pcat.html
http://www.jackspcs.com/pmk.htm

A Google search for Pyro Film Developers will find lots
more.

--
--
Richard Knoppow
Los Angeles, CA, USA
dick...@ix.netcom.com

[IanG]

Yes there can be advantages and an increase in quality how much depends
on the way you work and the developer you choose.

Pyrocat HD gives finer grain, better sharpness and more tonality than
D76, although originally designed for LF negatives it's also used for
35mm &120 negatives.

In addition the negatives are extremely easy to print from, with
excellent highlights and shadow detail.

It's also a better developer for making negatives for Alt processes.

Ian

--
IanG

[Jean-David Beyer]

IanG wrote (in part):

> Yes there can be advantages and an increase in quality how much depends
> on the way you work and the developer you choose.
>
> Pyrocat HD gives finer grain, better sharpness and more tonality than
> D76,

What does "more tonality" mean?

I cannot believe it means a greater dynamic range, because films, with
very few exceptions these days, have way more dynamic range than can be
printed onto photographic papers.

While I no longer use D-76, it is certainly a fine-enough grain
developer for 4x5 negatives at sizes up to 16x20, I would say. And it is
certainly well capable of getting a density of 2.0 or greater from the
films with which I am familiar.

Now it may well produce a slightly different curve shape, though that is
mostly determined by the design of the film. And some people obviously
like different curve shapes from others. I prefer short toe curve shape,
where most people seem to prefer a longer toe than I do. The only
disadvantage of short toe, in my opinion, is that if you underexpose, it
is just not there. So if you pop away on street corners in rapidly
changing conditions, Garry Winogrand style, you may prefer a longer toe
than I do. I believe he mostly used Tri-X in his Leicas.

> although originally designed for LF negatives it's also used for
> 35mm &120 negatives.
>

--
.~. Jean-David Beyer Registered Linux User 85642.
/V\ PGP-Key: 9A2FC99A Registered Machine 241939.
/( )\ Shrewsbury, New Jersey http://counter.li.org
^^-^^ 13:05:01 up 13 days, 15:57, 4 users, load average: 4.42, 4.57, 4.56

[crai...@yahoo.com]

I've settled on PyroCat-MC as my main developer, especially with
medium format and this combo is very nice with HP5+. I've been a
darkroom rat for 40+ years and always maintained some "go-to"
combinations when things needed to be predictable and absolutely give
usable results. I also played with many films and developers because
it kept my interest and imagination stirred up. As I've gotten older
and tinker less, I've appreciated the PyroCat variants because of 3
primary reasons:

1. Superb highlight control.... It virtually eliminates clipping and
allows me to have great shadow detail and not fear blown highlights.
Most films behave predictably at 1/2 box speed as a great starting
point and exhibit this basic behavior.

2. Great skin tones. People pictures just seem to print themselves
with a beautiful tone spread that gives a 3D effect and depth to
faces. Its sharpness and edge effects make eyelashes pop but somehow
is also kind to crows' feet, etc.

3. It solved most of my scanning headaches. The tonal range depicted
and smooth grain characteristics are especially compatible with
scanner's rendition with very little of that grain scatter appearance.
The edge effects aid in adding an apparent sharpness that translates
well in the digital process.

Over the years, I've had good success and a good understanding of most
of Ilford's films, Fuji and many of Kodak's. I started with D-76 and
still respect it as a great soup that one could happily use forever
and give up very little to anything else in general duties. FG-7 was
a favorite for many years and I also enjoyed DDX following that. XTOL
and the new TMY-2 seem made for each other, too. I only mention these
details so you don't think I'm a Pyro fanatic who's been to the
mountaintop!

The process is also easy and streamlined... I use a 1 minute initial
slow inversions cycle, followed by 1 gentle inversion per minute
(seems to add a bit of edge effect without getting exaggerated).
Follow with a double water rinse (no stop bath) and then fixing in
TF-4. Following washing and a drop or 2 of wetting agents, they also
seem to sheet off and dry spot free, too. Some films show some
emulsion expansion (sort of a frosty look with bright back light) and
some show an etching/raised effect on the emulsion side but they seem
to settle down after drying.

I wish someone would have promoted giving it a try earlier in my
darkroom escapades. I would encourage giving it a shot. A neutral or
alkaline fixer can aid in keeping the stain effect consistent with
Pyro (they're effective and pleasant to use anyway).

[Darkroom User]

IanG;886420 Wrote:
>
> PYROCAT HD GIVES FINER GRAIN, BETTER SHARPNESS AND MORE TONALITY THAN
> D76, ALTHOUGH ORIGINALLY DESIGNED FOR LF NEGATIVES IT'S ALSO USED FOR
> 35MM &120 NEGATIVES.

>
> In addition the negatives are extremely easy to print from, with
> excellent highlights and shadow detail.
>
> It's also a better developer for making negatives for Alt processes.
>
> Ian

If it gives finer grain as well as better sharpness than D76, then it
must be good.
Will I actually see these differences with FP4 Plus and T-Max 400?
What dilution and times for the small Paterson-tanks?

--
Darkroom User

[IanG]

You'll mainly notice better sharpness, and ease of printing.

15mins @ 20° C at 1+1+100 normal inversion agitation is a good starting
point with most films except Fomapan. That was my time for a roll of
FP4 last week which is perfect.

I used to use Tmax 1000 & 400 with Pyrocat and it;s a great combination,
but I switched to Delta 100 & 400, and HP5 in LF because Tmax is so hard
to find in many places now but Ilford films are everywhere.

Ian

Darkroom User;886491 Wrote:
> If it gives finer grain as well as better sharpness than D76, then it
> must be good.
> Will I actually see these differences with FP4 Plus and T-Max 400?
> What dilution and times for the small Paterson-tanks?

--
IanG

[IanG]

No pre-soak, normal agitation, once a minute, half strength stop bath or
good water rinse, and an un-hardened fixer like Hypam or Ilford/Kodak
Rapid fixer.

Ian

QUOTE=Darkroom User;886505]Thank you for the dilution, temperature and
time. Do you use a pre soak or not and is the normal agitation at 1
minute intervals as with regular film developers?

--
IanG

[Darkroom User]

IanG;886500 Wrote:
> You'll mainly notice better sharpness, and ease of printing.
>
> 15mins @ 20° C at 1+1+100 normal inversion agitation is a good starting
> point with most films except Fomapan. That was my time for a roll of
> FP4 last week which is perfect.
>

> I used to use Tmax 100 & 400 with Pyrocat and it;s a great combination,

> but I switched to Delta 100 & 400, and HP5 in LF because Tmax is so hard
> to find in many places now but Ilford films are everywhere.
>

> IanThank you for the dilution, temperature and time. Do you use a pre soak

or not and is the normal agitation at 1 minute intervals as with regular
film developers?

--
Darkroom User

[Nicholas O. Lindan]

"Jean-David Beyer" <jeand...@verizon.net> wrote

> What does "more tonality" mean?

Nothing.

"Tonality" as applied to photography and as
near as I can tell means the writer, using
developer X and film Y, made some
photos he liked .

"More Tonality" means he "more liked" his
photos.

"Tonality" is a word that should be removed
from the language. We don't have "colorality"
or "tastality" and have never missed them.

I think. I hope. Better check.

Oh dear, "tastality" comes up with 14 hits,
"colorality" 47. Thankfully used in a
mocking context ...

I think we can say that negatives developed
in Pyro have more "Pyrality" and leave it
at that.

--
Nicholas O. Lindan, Cleveland, Ohio
Darkroom Automation: F-Stop Timers, Enlarging Meters
http://www.darkroomautomation.com/da-main.htm
n o lindan at ix dot netcom dot com

[Darkroom User]

Hi there,

I asked this question about pyro developers on the photobanter website
in a separate thread. For some reason, it seems to have got merged with
the thread about a Jobo atl3.
I am not sure how that happened (sorry). This is where I asked about
pyro.
http://www.photobanter.com/showthread.php?t=114087

Jean-David Beyer;886448 Wrote:
> IanG wrote (in part):-

> Yes there can be advantages and an increase in quality how much
> depends
> on the way you work and the developer you choose.
>
> Pyrocat HD gives finer grain, better sharpness and more tonality than

> D76,-

>
> What does "more tonality" mean?
>
> I cannot believe it means a greater dynamic range, because films, with
> very few exceptions these days, have way more dynamic range than can be
> printed onto photographic papers.
>
>
>

> --
> .~. Jean-David Beyer Registered Linux User 85642.
> /V\ PGP-Key: 9A2FC99A Registered Machine 241939.
> /( )\ Shrewsbury, New Jersey http://counter.li.org
> ^^-^^ 13:05:01 up 13 days, 15:57, 4 users, load average: 4.42, 4.57,
> 4.56

--
Darkroom User

[Richard Knoppow]

"Darkroom User" <Darkroom.U...@photobanter.com>
wrote in message
news:Darkroom.U...@photobanter.com...
>

Well, finer grain is open to the question of how that
was determined. Lots of developers yield finer grain than
D-76, some modern ones, notably Xtol, also deliver somewhat
higher speed but most fine grain developers loose some
speed.
Pyrochatichin, which is related to pyrogallic acid but
is a different chemical can be used in developers which have
strong edge/border effects. This gives the illusion of
sharpness. There is another effect of certain developers
containing pyro and its relatives, that is that it tans the
gelatin image wise. The variation of index of refraction
after development can lead to a similar kind of edge effect
which is visualized as "acutance" or the impression of
sharpness. Note that "acutance" is a Kodak term for this
illusion. High acutance films do not, in general, increase
resolution, in fact they may reduce it. However, where one
is working with small negatives acutance effects will
partially compensate for the lack of sharpness in the
lenses. Note also that border/edge effects, and hense
acutance, is of a fixed scale so that its effect is
dependant on the magnification of the image on viewing. It
can have a quite significant effect on 35mm negatives but
will be virtually invisible on a 4x5.
Graininess also gives the illusion of sharpness. A
somewhat blurry image when overlayed with a sharp grain
pattern will appear to be sharp, at least at first.

[Lew]

What about film speed? Are there any fine grain, staining developers
mixed with phenodone, for example, to give the speed increase we
experience with xtol?

[Richard Knoppow]

"Lew" <lew...@gmail.com> wrote in message
news:ec481232-75a4-4eee...@u26g2000yqu.googlegroups.com...

I don't know. Imagewise staining is produced by some
phenol type developers as is imagewise tanning. Pyrogallic
acid and Pyrochatichin (there are other spellings) are
formost among the staining developers but hydroquinone can
cause imagewise tanning without the staining. Pyro has been
mixed with other developing agents, particularly Metol, but
that was done beause the two tend to preserve each other and
extend the life of the developer. Curiously much of the
reseach done on Pyro developers before they were pretty much
supplanted by M-H types was to devise non-staining
developers. The reason is that the stain image affects the
printing density in a way that varies with the spectrum of
the printing illumination and with the spectral sensitivity
of the printing material, plus it can be difficult to
measure because the densitometer used must match the
spectral sensitivity of the printing material. All is much
easier when the image is neutral. You can get some idea of
the increase in effective density for blue-sensitive
materials by looking at the negative though a blue filter.
Its also possible to bleach out the silver image which
leaves only the stain image. That is one way of determining
the effectiveness of a developer in forming a stain image.
The effect desired by most workers using current
materials is the self-masking effect of the stain image when
used with variable contrast materials. It tends to lower the
contrast of the highlights flattening out the very high
contrast produced by some modern films. In effect it creates
a shoulder on the film characteristic. Might or might not be
desirable and may not be much of an effect on some material.
Grain is affected by many variables: the activity of
the developer is one, generally less active developers are
less grainy; another factor is the pH of the developer,
higher pH (more alkaline) tends to produce coarser grain;
the presense of halide solvents affects grain somewhat but
not for the reasons popularly supposed. The solvent, sulfite
in most developrs, does not "etch away the grains" but
rather affects the way the crystals grow as they are
developed. Up to a certain point the presense of a solvent
will increase film speed because it makes more development
centers available to the developer. This is one reason that
D-76 has become the reference standard for film speed. When
more solvent is present, or a stronger solvent such as
sodium thiocyanate, is used the film speed goes back down
because the solvent can destroy some of the latent image
centers.
The total range of speed variation from "normal" type
developers is about 3/4 stop more to 3/4 stop less than
D-76. Some Phenidone developers, notably Xtol, T-Max RS,
Microphen, as examples, increase speed about 3/4 stop. Some
very fine grain developers such as Perceptol and Microdol-X
decrease it about 3/4 stop. About the only developers which
loose more speed than this are the old fashioned
paraphenylenediamine super fine gain developers. A pure PPD
developer (with no other agent added) can loose as much as 5
stops! These developers can also produce severe dichroic fog
on modern films and do not, for the most part, produce any
finer grain than Perceptol or Microdol-X
In general, film speed and fine grain are not
compatible. Probably the best compromise is Xtol which
yields slightly finer grain and slightly higher speed than
D-76 along with good sharpness and good tonal rendition.
Whatever reliability problems it had in the past seem to
have been cured.

[Thor Lancelot Simon]

In article <Darkroom.U...@photobanter.com>,

Darkroom User <Darkroom.U...@photobanter.com> wrote:
>
>IanG;886420 Wrote:
>>
>> PYROCAT HD GIVES FINER GRAIN, BETTER SHARPNESS AND MORE TONALITY THAN
>> D76, ALTHOUGH ORIGINALLY DESIGNED FOR LF NEGATIVES IT'S ALSO USED FOR
>> 35MM &120 NEGATIVES.
>

>If it gives finer grain as well as better sharpness than D76, then it
>must be good.

It also gives world peace and free beer. You can be sure it is excellent.

--
Thor Lancelot Simon t...@rek.tjls.com
"All of my opinions are consistent, but I cannot present them all
at once." -Jean-Jacques Rousseau, On The Social Contract

[David Nebenzahl]

On 8/11/2010 9:52 AM Thor Lancelot Simon spake thus:

> In article <Darkroom.U...@photobanter.com>,
> Darkroom User <Darkroom.U...@photobanter.com> wrote:
>>
>> IanG;886420 Wrote:
>>
>>> PYROCAT HD GIVES FINER GRAIN, BETTER SHARPNESS AND MORE TONALITY THAN
>>> D76, ALTHOUGH ORIGINALLY DESIGNED FOR LF NEGATIVES IT'S ALSO USED FOR
>>> 35MM &120 NEGATIVES.
>>
>> If it gives finer grain as well as better sharpness than D76, then
>> it must be good.
>
> It also gives world peace and free beer. You can be sure it is excellent.

My sentiments toward pyro as well. Not worth messing with, unless one is
part of the more-exotic-than-thou brigade.

--
The fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.

- Comment from an article on Antiwar.com (http://antiwar.com)

[Darkroom User]

David Nebenzahl;886934 Wrote:
>
>
> IanG;886420 Wrote:
> -

> PYROCAT HD GIVES FINER GRAIN, BETTER SHARPNESS AND MORE TONALITY THAN
> D76, ALTHOUGH ORIGINALLY DESIGNED FOR LF NEGATIVES IT'S ALSO USED FOR

> 35MM &120 NEGATIVES.-

>
> If it gives finer grain as well as better sharpness than D76, then
> it must be good.
>

> [/I][/COLOR]
>
> IT ALSO GIVES WORLD PEACE AND FREE BEER. YOU CAN BE SURE IT IS
> EXCELLENT.[/I][/COLOR]

>
> My sentiments toward pyro as well. Not worth messing with, unless one is
>
> part of the more-exotic-than-thou brigade.
>
>

> -- I am new to the darkroom and my questions concerning pyro are genuine. I
had read on various sites about pyro developers including WD2D, PMK and
Pyrocat-HD. If these developers offer no advantage over standards like
D76, ID11 or XTol, then I will choose one of those instead.

Please help me to learn, rather than post replies that come across as
being sarcastic.
I really do want to try to understand what is good darkroom practice,
such as choosing the right processes and materials. I have many
questions that I want to post here on photobanter.

--
Darkroom User

[David Nebenzahl]

On 8/12/2010 12:15 AM Darkroom User spake thus:

> David Nebenzahl;886934 Wrote:
>
>> IanG;886420 Wrote:
>>
>> PYROCAT HD GIVES FINER GRAIN, BETTER SHARPNESS AND MORE TONALITY THAN
>> D76, ALTHOUGH ORIGINALLY DESIGNED FOR LF NEGATIVES IT'S ALSO USED FOR
>> 35MM &120 NEGATIVES.-
>>
>> If it gives finer grain as well as better sharpness than D76, then
>> it must be good.
>>
>> [/I][/COLOR]
>>
>> IT ALSO GIVES WORLD PEACE AND FREE BEER. YOU CAN BE SURE IT IS
>> EXCELLENT.[/I][/COLOR]
>>
>> My sentiments toward pyro as well. Not worth messing with, unless one is
>> part of the more-exotic-than-thou brigade.
>

> I am new to the darkroom and my questions concerning pyro are
> genuine. I had read on various sites about pyro developers including
> WD2D, PMK and Pyrocat-HD. If these developers offer no advantage over
> standards like D76, ID11 or XTol, then I will choose one of those
> instead.
>
> Please help me to learn, rather than post replies that come across as
> being sarcastic. I really do want to try to understand what is good
> darkroom practice, such as choosing the right processes and
> materials. I have many questions that I want to post here on
> photobanter.

I was being sarcastic, but I do take your concerns seriously. My serious
answer to your queries about pyro developers is really "don't bother".
It's not worth the hassle. You can get wonderful results using any of an
array of readily-available conventional developers. So unless you insist
on doing something peculiar, boutique-y and idiosyncratic, stick with
D-76/ID-11, Microdol-X, Xtol, etc.

By the way, just curious: what's with the strange quoting style you used
(putting previously-quoted material in ALL CAPS, with non-functional
"tags", like [/COLOR])? That in itself is kinda like using pyro. I'm
just saying ...

[Darkroom User]

David Nebenzahl;886997 Wrote:
> On 8/12/2010 12:15 AM Darkroom User spake thus:

> [i]
> David Nebenzahl;886934 Wrote:
> [color=green][i]

> IanG;886420 Wrote:
>
> I was being sarcastic, but I do take your concerns seriously. My serious
>
> answer to your queries about pyro developers is really "don't bother".
> It's not worth the hassle. You can get wonderful results using any of an
>
> array of readily-available conventional developers. So unless you insist
>
> on doing something peculiar, boutique-y and idiosyncratic, stick with
> D-76/ID-11, Microdol-X, Xtol, etc.
>
> By the way, just curious: what's with the strange quoting style you used
>
> (putting previously-quoted material in ALL CAPS, with non-functional

> "tags", like )? That in itself is kinda like using pyro. I'm

> just saying ...
>
>
> --
> The fashion in killing has an insouciant, flirty style this spring,
> with the flaunting of well-defined muscle, wrapped in flags.
>

> - Comment from an article on Antiwar.com (http://antiwar.com)I am posting through the Photo-Banter site: www.photobanter.com
and those "tags" come up when I reply, although I do highlight certain
quotes in bold type.

By posting through this site, it helps to prevent receiving spam emails,
although I am not sure if I am getting to read all of the replies to the
threads.

Thank you for your reasonable reply to stick with regular developers. I
was curious to know why some people use pyro developers instead of
normal non staining developers and what they perceive their advantages
to be.
I am here to learn from the more experienced photographers and darkroom
users. :-)

--
Darkroom User

[Lew]

Isn't there also the claim that, as development & tanning progress in
highlight areas, the emulsion physically compresses (as a result of
the tanning) thereby holding less developer? ie there is even more
moderation of highlight densities than there is via the mechanism of
developer exhaustion alone.
I haven't tested this extensively, but my limited experience leads me
to believe that, on a very sunny day, with the sun overhead, plus
areas of deep shadow, using iso 200 - 400 films, I did obtain easy to
print negatives with plenty of highlight detail.

[David Nebenzahl]

On 8/13/2010 1:18 AM Darkroom User spake thus:

> I am posting through the Photo-Banter site: www.photobanter.com and
> those "tags" come up when I reply, although I do highlight certain
> quotes in bold type.
>
> By posting through this site, it helps to prevent receiving spam
> emails, although I am not sure if I am getting to read all of the
> replies to the threads.

OK, you're forgiven: it's not your fault. The software you're using to
post (Photobanter's forum software) is brain-damaged, at least where
quoting text is concerned.

Most of us here access Usenet (that's where these threads reside) the
conventional way, using a mail client (aka "newsreader"), which shows
the newsgroup the way [insert name of deity here] intended. You might
try it yourself sometime. Actually more direct than going through a web
site.

And it's very easy to post without receiving spam: just do like me and
use a phony "handle". Zero spam.

[Richard Knoppow]

"Darkroom User" <Darkroom.U...@photobanter.com>
wrote in message
news:Darkroom.U...@photobanter.com...
>

I think it is always interesting to experiment and
learn. There is a definite effect of highlight compression
when using a staining developer with variable contrast
printing materials. Its quite measureable but may not be
worth doing or may not be desirable for all images.
The newer pyro formulas, like PMK are attempts to
overcome some of the faults of the classical formulas,
mostly that they tended to be grainy and somewhat
unpredictable. The grain comes mainly from being active,
most of these formulas use sodium carbonate or some
equivalent as accelerators. They were necessary for the
films which were contemporary with the developer. they work
with newer films, especially when diluted more than the
original instructions indicate.
Formulas like the late ABC Pyro as published by Kodak,
Ansco, and others, is fairly long lived in stock solutions
and has relatively constant activity. Kodak D-7 is a
Pyro-Metol formula with somewhat longer life in a tank or
tray than ABC. There are a lot of variations. In my list are
some special formulas including Kodak's version intended to
maximize the stain image.
Note that some users of PMK or Rolo Pyro suggest an
after-bath in the developer to maximize the stain. What that
does is to produce an overall stain, which is _not_
desirable rather than the imagewise stain which is what you
want. A properly developed pyro negative should have little
or no stain in the clear portions but a noticable yellow,
greenish, or brownish stain following the image. The tanning
is visible as a relief image on the dry film when held so
that light reflects from the emulsion surface. Tanning
developers were highly developed for use in producing the
relief images used in the Kodak Dye Transfer process and
Flexichrome process, each of which made use of the tanning
to make parts of the emulsion more resistant to being
removed by hot water. When "developed" by rinsing in the
water the remaining emulsion followed the iamge exactly and
could be used for absorbing dyes either for direct use
(Flexichrome) or for transfer to a support paper in a
process similar to lithography. An earlier version of the
dye transfer process, called the Eastman Wash-Off Relief
process used a different method of differential hardening,
namely a bichromate process similar to that used for
Carbon/Carbro. If you are interested in these old processes
do a Google search for "alternative processes". Most are
still practiced and can produce beatiful results. However, I
suggest for someone starting out to make life simpler by
using well-established packaged materials. Once you get
control of the overall process of development and printing
you can try experimenting with mix your own chemistry. Most
of it is not difficult to do. There are NO magic developers
but some have definite personalities which can make them
interesting. Pyro is of historical importance, it was the
first organic reducing agent to be discovered. I would not
discourage anyone from trying it out but work with something
more modern first. At this time probably the closest thing
to an "optimum" developer is Kodak Xtol. Next choice is
D-76, which is close to optimum for nearly anything and is
perfectly reliable.
After having used a lot of print developers I have gone
back to plain old Dektol. The published formula D-72 is
about the same stuff. Ilford makes an equivalent. Ilford
Bromophen is a Dektol type developer that uses Phenidone in
place of Metol. It is better for you if you are sensitive to
Metol, which some people are and tends to give more neutral
colored images with some materials. It is perfectly
satisfactory. There are about a zillion print developer
formulas that go to show simply how imprecise one can be in
formulating:-) There is not much difference from one to
another. As far as warm vs cold tone, that is mostly a
property of the emulsion. While it is influenced by the
developer its mainly established by the paper. Developers
can have some influence on toning but that is often related
to the amount of bromide in them or other variations that
can be had by varying around a standard formula.
One of the biggest differences between B&W and color
photography is the lack of standardization in B&W. Color
processing is very tighly specified and controlled and,
while some variation is possible, the range of variation
within which satisfactory color can be obtained are fairly
limited.

[Richard Knoppow]

"Lew" <lew...@gmail.com> wrote in message

news:db44e57c-6a79-42e1...@c10g2000yqi.googlegroups.com...

I have never seen this suggested and doubt very much if
it happens. Developer penetrates by diffusion from the
surface. The "hardness" of the gelatin has little to do with
it. AFAIK, there is no such action due to differential
hardening.
There is a differential imagewise shrinkage of the
emulsion but it probably happens as the emulsion dries. One
result of this is an acutance effect due to a difference of
index of refraction along the demarcation of high and low
density areas. It also produces a distortion of the image on
a very small scale but enough so that tanning developers are
undesirable for photo metrology purposes.

--

[Darkroom User]

Unfortunately, Apple-Mail cannot be used for Newsgroups. I have edited
out the color tags this time. :-)

--
Darkroom User

[Thor Lancelot Simon]

In article <Darkroom.U...@photobanter.com>,
Darkroom User <Darkroom.U...@photobanter.com> wrote:
>

>Unfortunately, Apple-Mail cannot be used for Newsgroups. I have edited
>out the color tags this time. :-)

But you top-posted, which is every bit as rude. Stop doing that. Your
new material should go between and below what you quote; never above it.

[David Nebenzahl]

On 8/14/2010 2:36 AM Darkroom User spake thus:

> Unfortunately, Apple-Mail cannot be used for Newsgroups. I have edited
> out the color tags this time. :-)

Then get something suitable for newsgroups. Like Thunderbird (what I
use), which is free. (Also works for email.) Go to
http://www.mozillamessaging.com/en-US/thunderbird to get it.

And as someone else pointed out, it's rude and goes against the grain
here to top-post. Just look at other postings here to see what the
convention is.

[IanG]

That's a good summing up, except Pyrocat negatives also print
remarkable easily with conventional bromide/chloro-bromide
paperspapers

Those who spout out against Pyro developers have usually never tried
them. or are too inexperienced to get the best out of any developer.

Ian

[IanG]

Pyrocatechin (and Pyrogallol) work by acting on the surface of the
emulsion tanning & hardening the emulsion as the developers is used
and oxidises, particularly in the highlights. It's the basis of the
Pyrocatechin surface developers used to control high contrast lighting
as advocated by LP Clerc and Hans Windisch etc. So yes you are
correct.

The same effect is used in some Lith/Graphic arts developers, German
formulae often used Pyrocatechin in place of Hyrdroquinone, the two
are to some extent interchangeable. Kodak also used Pyrocatechin
instead of Hydroquinone in HC110 for a while.

Ian

[IanG]

On 9 Aug, 07:32, "Nicholas O. Lindan" <s...@sig.com> wrote:
> "Jean-David Beyer" <jeandav...@verizon.net> wrote

>
> > What does "more tonality" mean?
>
> Nothing.
>
> "Tonality" as applied to photography and as
> near as I can tell means the writer, using
> developer X and film Y, made some
> photos he liked .
>
> "More Tonality" means he "more liked" his
> photos.
>
> "Tonality" is a word that should be removed
> from the language.  We don't have "colorality"
> or "tastality" and have never missed them.
>
> I think.  I hope.  Better check.
>
> Oh dear, "tastality" comes up with 14 hits,
> "colorality" 47.  Thankfully used in a
> mocking context ...
>
> I think we can say that negatives developed
> in Pyro have more "Pyrality" and leave it
> at that.
>
> --
> Nicholas O. Lindan, Cleveland, Ohio

> Darkroom Automation: F-Stop Timers, Enlarging Metershttp://www.darkroomautomation.com/da-main.htm

> n o lindan at ix dot netcom dot com

If you don't understand the word Tonality I suggest you think about
the subtleties of of how tones change within an image, it's not
measured with a densitometer, it's not scientific and it's more
important to image quality.

ian

[Nicholas O. Lindan]

"IanG" <i...@lostlabours.co.uk> wrote:

> Nicholas Lindan wrote:
> > > What does "more tonality" mean?
> > Nothing.
> > "Tonality" as applied to photography and as
> > near as I can tell means the writer, using
> > developer X and film Y, made some
> > photos he liked.

> If you don't understand the word Tonality I suggest you think about

> the subtleties [sic] of of [sic] how tones change within an image, it's

> not
> measured with a densitometer, it's not scientific and it's more
> important to image quality.

I can see I understand the word very well.

[Jean-David Beyer]

The subtleties of how the tones (reflectances) change within an image
are shown perfectly well in the D/H curve of the printing system, from
subject to negative to positive print. And these things are measurable
with a spot-meter, a transmission densitometer, and a reflection
densitometer, respectively. When looking at a print, the human eye
replaces the reflectance densitometer, of course.

But I fail to see how "more tonality" can mean anything. The difference
between the minimum and maximum density of a print can be changed a bit
by technical means, and that could mean something. The average slope of
the D/H curve can be changed by changing the development time (contrast
adjustment). So you could have more lightness, more contrast, etc. But
those are not so much subtleties as normal results of the photographic
process. Changing the fundamental shapes, such as the contrast in the
toe, the "straight line", and the shoulder of the print might be subtle,
to the extent that it can be accomplished, but there you really need to
illustrate what you mean by showing the curves themselves. "More" or
"less" are meaningless in this context.

--
.~. Jean-David Beyer Registered Linux User 85642.
/V\ PGP-Key: 9A2FC99A Registered Machine 241939.
/( )\ Shrewsbury, New Jersey http://counter.li.org

^^-^^ 07:15:01 up 8 days, 10:34, 3 users, load average: 4.80, 4.91, 4.93

[Richard Knoppow]

"Jean-David Beyer" <jeand...@verizon.net> wrote in message
news:i4j4g...@news3.newsguy.com...

This is the kind of rubbish one finds in high end
audio. The claim that something can be sensed but not
measured. Since your senses _are_ measuring things any
difference that can be seen or heard can be measured. To say
otherwise is to deny the lessons learned from the entire
history of science. There is a perfectly enormous amount of
valid material on tone reproduction in photgraphic processes
in the literature. I strongly suggest people who want some
real understanding read some of it.