pyro plus paper developer

I have seen an article Donald Miller has published at unblinkingeye
about a paper developer based in phenidone+pyrocathecol+pyrogalol:
http://unblinkingeye.com/Articles/Py.../pyroplus.html
and I would like to know the following questions about this new paper
developer
-whats the real advantage compared with dektol I must recognize his
print is extremely good with very nice highligts and shadow details
but how much of it is due to negative or paper developer
-Does this developer tans paper gelatin like pyro negatives does?

"fnovau" wrote in message
om...
I have seen an article Donald Miller has published at
unblinkingeye
about a paper developer based in
phenidone+pyrocathecol+pyrogalol:
http://unblinkingeye.com/Articles/Py.../pyroplus.html
and I would like to know the following questions about
this new paper
developer
-whats the real advantage compared with dektol I must
recognize his
print is extremely good with very nice highligts and
shadow details
but how much of it is due to negative or paper developer
-Does this developer tans paper gelatin like pyro
negatives does?

You never know what will work but this looks like kitchen
chemistry to me. For one thing, there is no sulfite or other
preservative in it so my suspicion is that it will cause
severe overall staining and have very short life. There are
other preservatives than sulfite but none of them are listed
either. Perhaps there is an error in the formula as given.
Pyro paper developers have been published in the past.
They produce a stain image, just as the negative developrs
do. This can be useful as a warm tone developer.
This thing looks to me like the 1930s formulas compounded
with little or no knoledge of chemistry based simply on
throwing together stuff that seems attractive. AFAIK
Phenidone has no superadditivity with Pyro or chatachol
(Pyrochatichin). Why is it there? Why use this combination
at all? The imgages look OK but I suspect were not
developed in the formula as given.
Also, the true Dmax of printing paper is virtually never
used. One can see this by looking at a print with lots of
shadow detail by _transmitted_ light. Generally, you will
find detail in the blacks which do not show up under normal
reflected illumination. Dmax is determined partly by the
emulsion and partly by the texture and surface of the paper,
developer has little effect providing development has been
carried out fully. Developers also have little effect on
paper contrast despite the existence of so called low
contrast developers and variable contrast developers. Unlike
film, paper is developed to reach nearly its maximum density
and minimum density is usually paper white (except for
special images where gray highlights are for some reason
desirable). Film, OTOH, is developed to some intermediate
maximum density, generally far below the capability of the
emulsion. This allows for a range of contrasts by means of
changing the degree of development.
There are developers other than the Dektol type (lots of
others are essentially identical) which can have an effect
on image color. In particular Phenidone based developers,
like Ilford Bromophen and Agfa Neutol Plus (Phenidone and
Ascorbic acid) can produce more neutral tones. However, the
addition of Benzotriazole to Dektol may accomplish the same
purpose.
By the same token, and with respect to Chamlee and Smith,
who produce beautiful prints, I don't think there is any
magic to Amidol. A properly compounded conventional
developer will produce equally neutral color and densities.


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

Subject: pyro plus paper developer
From: "Richard Knoppow"

[snip]
Dmax is determined partly by the
emulsion and partly by the texture and surface of the paper,
developer has little effect providing development has been
carried out fully. Developers also have little effect on
paper contrast despite the existence of so called low
contrast developers and variable contrast developers.
************************************************** ***

If I have a very contrasty negative I will often switch to Selectol Soft
because that makes it possible for me to get the image I'm looking for. So,
what is going on when I use Selectol Soft 1+1 at 2.5 minutes compared to Dektol
1+2 for the same 2.5 minutes? If exposure and contrast filter are such that
the whites are white and the blacks are black then am I just getting a
different shape to the density vs exposure curve? Or do you think that I'm
really not getting to the same level of black when I use SS?

Curtis

"Richard Knoppow" wrote in message . AFAIK
Phenidone has no superadditivity with Pyro or chatachol
(Pyrochatichin). Why is it there? Why use this combination
at all?

I think you may be wrong here. The Pyrocat HD formula is a phenidone/
chatachol based film developer devised by Sandy King and seems to have
superadditive properties. With less than 1 gram of developing agent
per liter it builds silver/stain density approaching ABC pyro, which
containg 6g of developing agent per liter. With a film like HP5+ it is
easy to build enough density to reach a CI of 1.5 for alt process
or AZO printing,
something nearly impossible with a superadditive pyrogallol/metol
developer like PMK. Pyrocat HD is also very useful for extreme minimal
agitation and seems to be working for some with stand and semi stand
development at very weak dilutions. My own experiments with semi stamd
development have produced negs with apparant sharpness like nothing I
have seen before. I really doubt any high solvent content developer
like D-76 could do this due to infectious development and other
factors , but I admit I have not done a back to back test.
I realise you were refering to the paper developer, which I have not
tried.



By the same token, and with respect to Chamlee and Smith,
who produce beautiful prints, I don't think there is any
magic to Amidol. A properly compounded conventional
developer will produce equally neutral color and densities.

I think the real advantage to using amidol with azo is the contrast
control with water bath development. That being said, I have been way
down the exotic paper/ film/developer road and have had all sorts or
results, good and bad. I recently shot some PJ event type stuff on
HP5+/D-23 printed on Ilford MG developed in D-72 and on the first set
of proofs had prints that had a glow like nothing I have been seeing
on the exotic paper / developer combos. Go figure....

Brook

(brook) wrote


I recently shot some PJ event type stuff on
HP5+/D-23 printed on Ilford MG developed in D-72 and on the first set
of proofs had prints that had a glow like nothing I have been seeing
on the exotic paper / developer combos. Go figure....

Brook


"Go figure..." I keep myself humble by reminding myself of that.
So what am I doing now. Quite by chance a homebrew print developer I
compounded demonstrated lith characteristics.
That's way into left field for me at this time. But ah-lithing I go,
Hi-Ho. Dan

Richard Knoppow wrote:

"fnovau" wrote in message
om...
I have seen an article Donald Miller has published at
unblinkingeye
about a paper developer based in
phenidone+pyrocathecol+pyrogalol:
http://unblinkingeye.com/Articles/Py.../pyroplus.html
and I would like to know the following questions about
this new paper
developer
-whats the real advantage compared with dektol I must
recognize his
print is extremely good with very nice highligts and
shadow details
but how much of it is due to negative or paper developer
-Does this developer tans paper gelatin like pyro
negatives does?

You never know what will work but this looks like kitchen
chemistry to me. For one thing, there is no sulfite or other
preservative in it so my suspicion is that it will cause
severe overall staining and have very short life. There are
other preservatives than sulfite but none of them are listed
either. Perhaps there is an error in the formula as given.
Pyro paper developers have been published in the past.
They produce a stain image, just as the negative developrs
do. This can be useful as a warm tone developer.
This thing looks to me like the 1930s formulas compounded
with little or no knoledge of chemistry based simply on
throwing together stuff that seems attractive. AFAIK
Phenidone has no superadditivity with Pyro or chatachol
(Pyrochatichin). Why is it there? Why use this combination
at all? The imgages look OK but I suspect were not
developed in the formula as given.
Also, the true Dmax of printing paper is virtually never
used. One can see this by looking at a print with lots of
shadow detail by _transmitted_ light. Generally, you will
find detail in the blacks which do not show up under normal
reflected illumination. Dmax is determined partly by the
emulsion and partly by the texture and surface of the paper,
developer has little effect providing development has been
carried out fully. Developers also have little effect on
paper contrast despite the existence of so called low
contrast developers and variable contrast developers. Unlike
film, paper is developed to reach nearly its maximum density
and minimum density is usually paper white (except for
special images where gray highlights are for some reason
desirable). Film, OTOH, is developed to some intermediate
maximum density, generally far below the capability of the
emulsion. This allows for a range of contrasts by means of
changing the degree of development.
There are developers other than the Dektol type (lots of
others are essentially identical) which can have an effect
on image color. In particular Phenidone based developers,
like Ilford Bromophen and Agfa Neutol Plus (Phenidone and
Ascorbic acid) can produce more neutral tones. However, the
addition of Benzotriazole to Dektol may accomplish the same
purpose.
By the same token, and with respect to Chamlee and Smith,
who produce beautiful prints, I don't think there is any
magic to Amidol. A properly compounded conventional
developer will produce equally neutral color and densities.

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


Pyro and phenidone are quite synergistic. So are phenidone and catechol.
I think Donald miller's pyro paper developer has quite a bit of sulfite.
Something like 40 g/l IIRC. That is what keeps it from being a very
strongly staining developer.