My Home Brew
spectrum
> >Jimmy Tung wrote:
> >>
> >> jcarb...@aol.com wrote:
> >> : I have mixed all my own chemistry from scratch for many years I have
> >> : gathered formulas for most camera and motion picture film, color and black
> >> : and white. Mixing chemistry from scratch is a dieing hobby. There are
> >> : very few of us left. I find that is the only way to have complete
> >> : control.
Spectrum wrote
> > I have to agree to a certain extent that the majority of darkroom
> >workers don't have a clue when it comes to formulating,testing and using
> >a developer. And even when you do find someone who mixes his/her own
> >formulas, they're actually using someone else's recipe. Nothing wrong
> >with that ,but it seems a little wasteful of a persons time to mix a developer that is available over the counter. And then to make matters worse they don't
> >record data accurately an sometimes not at all. In S.Anchells book all
> >he has done was to reprint a culmination of formulas that had been only
> >slightly forgotten. And then he gave little if any recommendations for
> >use with todays films !
> >
> > Do you have any old formulas or your own creations that contain
> >p-aminphenol hydrochloride ? What is your favorite developer/fim
> >combination ? Why ?
> >
> > spec...@cybercomm.net
> I responded earlier to your post (I think) about p-Aminophenol
> developers and suggested Anchell's book (and posted a formula). I
> mentioned this book because it is in print and is more easily
> available than other sources. your criticism is right in that he has
> only reprinted old formulas without commenting much, if at all, on
> thier performance or usefulness.
> There are hundreds of developer formulas in the literature. Many
> are _very_ obsolete and appear to have been formulated by cut-and-try
> by someone not trained in chemistry (especially those from more than
> about 75 years ago). Some are merely knock-offs of some patented
> formula with enough modification to avoid infringment. An example of
> this last is the variation of D-76.
> Kodak D-76 (the original)
> Times have changed, Heigh-Ho.
> ---
> Richard Knoppow
> Los Angeles, Ca.
> dick...@ix.netcom.com
Richard,
Yes you had responded to this and I appreciate your input. I
seem to
need to clrify what I'm looking for. After looking over the formula for
Rodinal and creating my Divided p-Aminophenol hydrochloride Developer, I
purchased a old copy ('84) of the Photo Lab Index. Upon reviewing the
chemical section I found that Agfa was not the only company that made a
p-aminophenol type of developer. In fact almost every manufacturer had
one in the works or on the market. Here are some of the names;
Citol, Kodelon(Kodak), Energol, Freedol, Indianol, Kathol,
Unal,
Para,Azol and Actizol.
My interest is not only in these formulas, but also in why did
all of
the manufacturers stop producing it ? It seems odd that they all had
similar formulas available but only Rhodinal survived.
One other point of intrest is that p-aminophenol hydrochloride
has a
higher soluability than either the freebase or Elon, which it is very
similar to. In fact one of the major differences between Elon and p-AH,
is Elon's nasty little toxins that cause dermatitas. Elon is harder to
produce in a pure form.
Here follows a note that I wrote to someone on the net that will
explain where I'm going and what I've been doing and maybe why.
I have always liked the idea of a split stock developer, even
more so
after I tried G.Hutchings PMK. His formula has a shelf life that could
well be measured in decades. Well anything that can offer even half of
that is plenty for me. After all I'm after consistancy not just
stability, but stability is a factor of consistancy.I always liked
Rodinal but when I looked at the formula I couldn't believe my eyes.
What a mess ! The proverbial ton of alkali composed of pot.hydroxide and
pot.sulfite , all to get the p-aminophenol into solution and hopefully
keep it there. To keep the alkali in check, Agfa uses pot.metabisufite,
which would also help preserve the developer. The net effect is to
create an environment that is perfect for grain
swelling. And bromide? For what ? Surely not an antifoggant as
p-aminophenol doesn't produce a lot, if any. Well redundancy abounds!
One other thing that used to bother me about the popular
formulas such
as D-76,T-Max and particularly the X-Tol,or any phenidone developer, was
that you had to stand by your tank for the entire developement cycle
just to be certain that your adgitataion was on the money. If you
don't,Viola!, uneven developement. Well after reading Steve Anchells
article in the now defunct Camera and Darkroom on glycin I learned that
not all developers are sensitive to bromide drag and its streaking
effects.
So I started playing with my chemicals to find the best working
combination. This revealed some surprising results and contradictions to
what I had been taught. Such as that pot.carbonate will "blow out the
grain" when compared to Kodalk and other mild alkali. When in fact if
the ph is consistant it makes no difference at all. So why store and use
pounds of borax when a few ounces of carbonate are just as good or
better ?
As I said I wanted a split stock to give a good shelflife. This stock
should be fairly concentrated so that a fairly small quantity can be
mixed to produce a signifigant amount of working strength developer.
Hutchings PMK formula is mixed 1A+2B+100water. A good starting point, I
thought, and aimed for that specific concentration. Next I had to decide
on the parameters for my mix. I wanted a stand type of formula, which
would enhance adjacency effects, while giving TMX the highlight
compensation that it needs. In theory this would also provide a speed
gain which can always be used. Especially as I love the 4x5 format and
commonly use f/22 or f/32 on my G-Claron 240f/9. The rest of my formula
is, well lets say spartan.
Without further boredom, here is my formula. If you try it,
please let
me know your results. As you can see its very frugal. I consider it to
be the best of all worlds. When mixed to working strength it can hardly
be considered toxic as it contains almost nothing. It is easy and
inexpensive to compound. All chems are readily available in small and
large quantity. If you have any further questions don't hesitate to mail
or call me at Spectrum Photographic Inc.,908-349-5915.
Spectrum #1
A Water@100degrees 300ml
91% IsoAlcohol 25ml
Pot.Metabisulfite 25.0g
p-Aminophenol Hydrochloride 25.0g
Water (room temp) to make 500ml
B Water (cool) 600ml
Sod.Hydroxide 20.0g
Borax 50.0g
Sod.Sulfite 150.0g
Water to make 1.0liter
I deliberately used the combination of borax and sod.hydroxide as to
limit the number of ions available for transfer to the developer. Again
this should have some slight compensating effect.
Dilute 1A + 2B + 100 Water and develope ;
TP 35mm - 40 minutes @ 70 degrees
TMX - 90 minutes @ 70 degrees
TMY - 80 minutes @ 70 degrees
Adgitation should be every 15 minutes or so, it's not to critical.
spectrum
Cyrus Gardner wrote:
>
> Hi,
> I'm pretty fascinated by all of this but from an entirely uninformed
> perspective. Could you pls comment on:
> 1. What do the films look like when developed in Spectrum #1?
> 2. Do you expect the shelf life to be huge?
> 3. Any side effects from handling/breathing the ingredients or
> mixtures?
> 4. Is agitation something like, "vigourously invert 4 times in 5
> seconds" [, then go do something else for 15 minutes or so . . .]?
>
> Thanks for your interesting posts.
>
> Cyrus Gardner
>
> spectrum <spec...@cybercomm.net> wrote:
> <major snips>
> >or call me at Spectrum Photographic Inc.,908-349-5915.
> >
> >Spectrum #1
> >
> >A Water@100degrees 300ml
> > 91% IsoAlcohol 25ml
> > Pot.Metabisulfite 25.0g
> > p-Aminophenol Hydrochloride 25.0g
> > Water (room temp) to make 500ml
> >
> >B Water (cool) 600ml
> > Sod.Hydroxide 20.0g
> > Borax 50.0g
> > Sod.Sulfite 150.0g
> > Water to make 1.0liter
> >
> >I deliberately used the combination of borax and sod.hydroxide as to
> >limit the number of ions available for transfer to the developer. Again
> >this should have some slight compensating effect.
> >
> > Dilute 1A + 2B + 100 Water and develope ;
> >
> >TP 35mm - 40 minutes @ 70 degrees
> >TMX - 90 minutes @ 70 degrees
> >TMY - 80 minutes @ 70 degrees
> >
> >Adgitation should be every 15 minutes or so, it's not to critical.
>
> Hi,
> I'm pretty fascinated by all of this but from an entirely uninformed
> perspective. Could you pls comment on:
> 1. What do the films look like when developed in Spectrum #1?
> 2. Do you expect the shelf life to be huge?
> 3. Any side effects from handling/breathing the ingredients or
> mixtures?
> 4. Is agitation something like, "vigourously invert 4 times in 5
> seconds" [, then go do something else for 15 minutes or so . . .]?
>
> Thanks for your interesting posts.
>
> Cyrus Gardner
Spectrum writes,
1) As to the appearance of the negatives they are sharp and crisp.
When
I say crisp I mean free of fog. The scale of the developed negative is
remarkable. From rich shadow detail to brilliant highlights, detail
abounds. Just try getting a paper that will hold it all !
2) Shelf life should be at least two years and I won't be surprised
if
it makes it to 5 years or more. Shelf life in most formulas is
compromised by the combination of the alkali and the developing agent(s)
which accelerates oxidation. However in a divided stock formula the
accelerator is kept seperate and mixed prior to use.G.Hutchings' PMK
formula, which originally inspired me to mix my own, is projected to
last 10 or more years.
3) All chemicals are toxic if ingested ! Bar none ! Oxygen will
kill you
just a little slower than chlorine. Now, regarding my formula,
p-aminphenol hydrochloride has about the same toxicity as any other
developing agent(e.g. ,hydroquinone, etc)and less than most. I'm
refering here to Elon,because of it's inherent impurities, p-phenylene
diamene and it's derivatives,as well as pyrogallol,catechol and Amidol.
As far as side effects, the Focal Encyclopedia and the Photo Lab Index
state that breathing the dust or vapor can cause asthma and contact with
the skin can cause dermatitis. I would suspect that my concoction is far
less likely to poison anyone or anything, than any developer currently
on the market when used according to my specs.
DO BE VERY CAREFUL WITH THE SODIUM HYDROXIDE!!!! One little spec
of
that stuff can really smart and any more, well you'll be going to the
hospital ! Now, when mixing sodium hydroxide ALWAYS use cool water and
add it slowly. If the solution gets to hot,let it cool.
4) Adgitation is always a big annoyance of mine. I don't even like
to
think about how many hours I've spent just waiting for the next cycle.
That's another reason I chose p-aminophenol hydrochloride, it's not as
sensitive to bromide drag as most other agents. You still have to
adgitate your film, just not as often ! I recommend 3 inversions every
10 or 15 minutes. And not so hard ! I once took a seminar with Scott
Griswold and he recommended shaking your film like a cocktail ! Ever
since then I've used a mild kind of roll and invert.This gives me even
development and keeps my highlights from going to hot.
This formula answered all of the problems that I have with
todays
formulations. Namely uneven developement, toxicity, cost, adgitation
time, shelf life and one thing you don't here to much about, consistancy
of formulation. I'm a big fan of Eastman Kodak, I believe they have most
of the best products on the market. However even they have sold me some
bad chemistry. Well they'll replace my film but that's as far as they
will go! So my time is wasted because some dolt pushed the wrong button.
Never again! This really happened! I climbed eight miles up a
trail,carring seventy pounds of equipment, in the Smokey Mountain
National Park and took several photos with my 4X5 and developed my film
in the to much hyped Xtol, and ruined my film! You see b/w is such a
small part of the market anymore that it really doesn't get the eye of
scrutiny that it needs to keep on it's toes. Digital is more glamorous,
and color negative more profitable. So by some new widgit and forget
about b/w ! What does dumbing down REALLY mean ?
If I can answer any more questions don't hesitate to write,
Spectrum Photographic Inc.
spec...@cybercomm.net
Cyrus Gardner
Hi,
I'm pretty fascinated by all of this but from an entirely uninformed
perspective. Could you pls comment on:
1. What do the films look like when developed in Spectrum #1?
2. Do you expect the shelf life to be huge?
3. Any side effects from handling/breathing the ingredients or
mixtures?
4. Is agitation something like, "vigourously invert 4 times in 5
seconds" [, then go do something else for 15 minutes or so . . .]?
Thanks for your interesting posts.
Cyrus Gardner
spectrum <spec...@cybercomm.net> wrote:
<major snips>
Michael Gudzinowicz
spectrum <spec...@cybercomm.net> writes:
[edited]
This is a _long_ post, but some of the conclusions bothered me after i
did some calculations on the "home brew" formula, and an old "Rodinal"
formula.
> My interest is not only in these formulas, but also in why did
>all of the manufacturers stop producing it ? It seems odd that they all
>had similar formulas available but only Rhodinal survived.
I have a lot literature from the turn of the century which includes
scores of photos with development details. I don't think the developer
was as popular as supposed.
Pyro is mentioned the majority of the time, followed by MQ developers
(similar to diluted D-72), then infrequent references to hydroquinone
and Rodinal. At that time, metol was considered "soft" for the
films, which led to the addition of hydroquinone in various ratios, or
the use of pyro/soda. p-Aminophenol wasn't used in combination with
hydroquinone. I'd speculate that metol was chosen because of better
speed, higher contrast and longer life in working solutions. It didn't
appear that compensating developers were desired for the wide variety of
papers available. For shooting extended scenes, modified pyro
developers were used. MQ developers were also the developers of choice
for "gaslight" papers.
> One other point of intrest is that p-aminophenol hydrochloride
>has a higher soluability than either the freebase or Elon, which it is
>very similar to. In fact one of the major differences between Elon and
>p-AH, is Elon's nasty little toxins that cause dermatitas. Elon is
>harder to produce in a pure form.
Metol's solubility in cold water is approx 50g/l, and 160g/l in hot
water, which is more than adequate for preparing concentrated
developers. The free base of the developing agents isn't that soluble,
but the phenolate salt is. However, the phenolate salts are not very
stable in air, which is the primary reason the acid salt powders are sold.
Actually, p-aminophenol and hydroquinone also can cause sensitization
and allergic reactions, and are not "safe' alternatives for a person
allergic to metol. (Read malpractice suit, and it isn't caused by metol
impurities.) The photographic literature seems to ignore the medical
literature when dealing with that topic.
The contact dermatitis was described by the early 1900's along with
"remedies". Other agents, such as phenidone (Bogisch, 1889) were
available then. The trend to avoid metol contact appears to be driven
by the legal system, which accounts for the popularity of PQ developers
in school darkrooms. And of course, one can develop allergies to them
(Q) or have an M allergy triggered by exposure to a PQ developer. It's
a nice idea to be "safe", but PQ, p-AP, etc., isn't the route. These are
all reactive compounds which can modify cellular consituents, turning
them into haptens.
Another nice compound which would have developing properties if it
weren't so insoluble, is urushiol, a 1,2 catechol with a long alkyl
group on the 3 position. Don't try it - it is the potent allergen in
poison ivy, which doesn't require pre-exposure.
Still, metol has been the preferred developing agent.
> Here follows a note that I wrote to someone on the net that will
>explain where I'm going and what I've been doing and maybe why.
>
> I have always liked the idea of a split stock developer, even
>more so after I tried G.Hutchings PMK. His formula has a shelf life that
>could well be measured in decades. Well anything that can offer even
>half of that is plenty for me. After all I'm after consistancy not just
>stability, but stability is a factor of consistancy.I always liked
>Rodinal but when I looked at the formula I couldn't believe my eyes.
>What a mess ! The proverbial ton of alkali composed of pot.hydroxide and
>pot.sulfite , all to get the p-aminophenol into solution and hopefully
>keep it there. To keep the alkali in check, Agfa uses pot.metabisufite,
>which would also help preserve the developer. The net effect is to
>create an environment that is perfect for grain swelling. And bromide?
>For what ? Surely not an antifoggant as p-aminophenol doesn't produce a
>lot, if any. Well redundancy abounds!
You are not aware of it, but the formula you proposed is more alkaline,
and very likely, less reproducible than traditional "Rodinal"
preparations. The detailed explanation follows after your formula.
Also, if "Rodinal" is properly prepared, it is very stable for years.
> One other thing that used to bother me about the popular
>formulas such as D-76,T-Max and particularly the X-Tol, or any phenidone
>developer, was that you had to stand by your tank for the entire
>developement cycle just to be certain that your adgitataion was on the
>money. If you don't,Viola!, uneven developement. Well after reading
>Steve Anchells article in the now defunct Camera and Darkroom on glycin
>I learned that not all developers are sensitive to bromide drag and its
>streaking effects.
One question which should be asked, is whether "bromide" is responsible
or whether rather poor buffering and agitation are the culprits. Since
the bromide development product released is HBr (hydrobromic acid), a
poorly buffered developer with an agent sensitive to pH may result in
local problems. If "bromide drag" is actually due to bromide, the
inclusion of a very small amount of bromide restrainer will completely
mask the small local concentration and its effect. I don't think that
bromide will affect streaking seen with poorly agitated pyro staining
developers, which are very sensitive to pH changes.
A bit of bromide can be a good thing, and often 0.25 g/l KBr was added
to D-76d and other developers which would later be replenished to ensure
consistency between unused and the replenished developers. The amount
of potassium/sodium chloride formed from p-AP*HCl has an insignificant
effect in comparison to KBr.
> So I started playing with my chemicals to find the best working
>combination. This revealed some surprising results and contradictions to
>what I had been taught. Such as that pot.carbonate will "blow out the
>grain" when compared to Kodalk and other mild alkali. When in fact if
>the ph is consistant it makes no difference at all. So why store and use
>pounds of borax when a few ounces of carbonate are just as good or
>better ?
If you keep the pH constant, you've neutralized the added K2CO3 along
the way, so the comparison isn't quite the same as old texts, which
threw in carbonate to raise the pH. Usually, carbonate is more more
basic in solution, is more effective in removing hardeners to promote
swelling and grain migration, and it releases CO2 gas when acidified in
a stop bath or fixer.
Borax was used in fine grain developers not only to act as a mild
"activator", but also as an emulsion hardener to prevent swelling.
Boric acid is used in some fixers for the same reason - as a hardener.
> As I said I wanted a split stock to give a good shelf life. This
>stock should be fairly concentrated so that a fairly small quantity can
>be mixed to produce a signifigant amount of working strength developer.
>Hutchings PMK formula is mixed 1A+2B+100water. A good starting point, I
>thought, and aimed for that specific concentration. Next I had to decide
>on the parameters for my mix. I wanted a stand type of formula, which
>would enhance adjacency effects, while giving TMX the highlight
>compensation that it needs. In theory this would also provide a speed
>gain which can always be used. Especially as I love the 4x5 format and
>commonly use f/22 or f/32 on my G-Claron 240f/9. The rest of my formula
>is, well lets say spartan.
(Just a comment - not everyone would agree that TMX requires
compensation, and the -1 grade or so highlight compensation achieved
with PMK and VC papers has turned some people off. Traditionally, many
pros & art photogs like Ektapan, TXP and PXP in HC110 A/B or DK 50 to
_expand_ high values.)
> Without further boredom, here is my formula. If you try it,
>please let me know your results. As you can see its very frugal. I
>consider it to be the best of all worlds. When mixed to working strength
>it can hardly be considered toxic as it contains almost nothing. It is
>easy and inexpensive to compound. All chems are readily available in
>small and large quantity. If you have any further questions don't
>hesitate to mail or call me at Spectrum Photographic Inc.,908-349-5915.
>
>Spectrum #1
>
>A Water@100degrees 300ml
> 91% IsoAlcohol 25ml
> Pot.Metabisulfite 25.0g
> p-Aminophenol Hydrochloride 25.0g
> Water (room temp) to make 500ml
>
>B Water (cool) 600ml
> Sod.Hydroxide 20.0g
> Borax 50.0g
> Sod.Sulfite 150.0g
> Water to make 1.0liter
>
>I deliberately used the combination of borax and sod.hydroxide as to
>limit the number of ions available for transfer to the developer. Again
>this should have some slight compensating effect.
>
> Dilute 1A + 2B + 100 Water and develope ;
>
>TP 35mm - 40 minutes @ 70 degrees
>TMX - 90 minutes @ 70 degrees
>TMY - 80 minutes @ 70 degrees
>
>Adgitation should be every 15 minutes or so, it's not to critical.
After reading the formula, and doing a few calculation, your times came
as a surprise, but one which may be understood.
For convenience, I've converted your formula to moles/liter to compare
it to an old "Rodinal" formula.
Home Brew: Molecular Amt.
Wt. (g per l) Molarity
Stock A:
p-AP*HCl 145.4 50.0 0.3439
K2O5S2 222.3 50.0 0.2249
Stock B:
Na2SO3 126.0 150.0 1.1905
NaOH 40.0 20.0 0.5000
B4Na2O7*10H2O 381.3 50.0 0.1311
When they are mixed, the HCl (strong acid) is completely neutralized by
NaOH (strong base) to form NaCl (ionized). The metabisulfite adds water
to "become" two bisulfites (2 KHSO3), which are neutralized by the
excess NaOH to form NaKSO3. (This is simplified; in solution there are
multiple equilibria.)
In a solution containing 1 part A, 2 parts B and 97 parts water (to
simplify the comparison, rather than + 100), the concentrations would
be the following before correction for neutralization:
Molarity Molarity
p-AP*HCl 0.0034
K2O5S2 0.0022
Na2SO3 0.0238
NaOH 0.0100
B4Na2O7*10H2O 0.0026
Note that the metabisulfite gives two bisulfite anions in solution,
0.0045 M KHSO3. The strong acid, HCl, and the weak acids, potassium and
sodium bisulfites contributed by metabisulfite (the ions mix in
solution), are neutralized by NaOH to give NaCl and NaKSO3 (more or
less). The neutralization requires 0.0045 moles/l NaOH for bisulfite,
and 0.0034 moles/l for HCl, leaving 0.0021 moles/l NaOH. Simplifying,
and ignoring a number of equilibria, the working solution composition is:
Molarity
p-AP 0.0034
Sulfites 0.0283 <- sum of Na2SO3 and NaKSO3
Tetraborate 0.0026
NaCl 0.0034
NaOH 0.0021 <- reduced due to neutralization
One of the traditional "Rodinal" preparations uses 20 g of p-AP*HCl and
60 g potassium metabisulfite dissolved in 250 ml of water. The HCl is
neutralized and bisulfite converted to sulfite by the addition of 40%
NaOH until almost all of the p-AP is in solution at a basic pH. That
titration requires 68 ml of 40% NaOH, after which the mixture is diluted
to 400 ml. If all of the p-AP is dissolved, bisulfite is added to
decrease pH until a small amount of precipitate appears.
Molecular Amt. Amt.
Rodinal: Wt. (g/400cc) (g per l) Molarity
p-AP*HCl 145.4 20.0 50.0 0.3439
K2O5S2 222.3 60.0 150.0 0.6747
NaOH 40.0 27.2 68.0 1.7000
Diluting the "Rodinal" with 99 parts water, and accounting for NaOH
neutralization by HCl and bisulfite:
Rodinal 1+99: Molarity Molarity
p-AP 0.0034
K2O5S2 0.0067 0.0135 <- as NaKSO3
NaCl 0.0034
NaOH 0.0170 0.0001 <- after neutralization of
HCl and bisulfite.
The amount of NaOH "left over" is variable, but minimal if the titration
is carried out as described.
The following table compares "Rodinal" with the "home brew" working
solutions diluted to a similar extent - approximately 1:100.
"Rodinal" "Home Brew"
Molarity Molarity
p-AP 0.0034 p-A 0.0034
Sulfites 0.0135 Sulfites 0.0283
NaCl 0.0034 NaCl 0.0034
NaOH 0.0001 NaOH 0.0021
Tetraborate 0.0026
The concentration of developing agent and sodium chloride is the same,
and the concentrations of Na/K sulfite is low, but in the same
ballpark. However, in addition to borax, "home brew" has an excess of
NaOH in comparison to "Rodinal", which would lead to the conclusion that
it is _more_ basic than "Rodinal". If so, it should be more active,
which doesn't appear to be the case based on the times given.
The excess NaOH and lack of activity is what caught my attention when
scanning the formula. The question is why that might be the case.
The "Rodinal" formulation has a couple of things going for it, which may
not be apparent, but are very important. If anyone thinks the formula
is trivial, it isn't.
1) The "Rodinal" pH:
By neutralizing the HCl with NaOH, the p-AP will come out of solution as
the free base, and go back into solution at a basic pH as the phenolate
anion in equilibrium with free base. By back titrating with bisulfite
crystals to get a small amount of precipitate, the pH of the solution is
reduced resulting in the increase of the ratio of free base to anion.
Eventually the free base reaches a concentration which limits its
solubility. In other words, the solubility of the free base is the pH
indicator. (Cute, reproducible & requires no meter.)
That approach solves other problems, such as impure bisulfite, NaOH and
p-AP*HCl, and NaOH exposure to air, converting it to carbonate.
2) The 40% NaOH solution is stable in air - carbonate is insoluble in
it, and therefore it doesn't reduce the pH. If you mix 40% NaOH w/v, it
will get _very hot_ - use a Pyrex beaker in a tray, and wear glasses and
gloves. I use di water, and let it stand overnight before decanting off
the 40% solution (a small amount of carbonate will precipitate out).
3) As it turns out, at the chosen endpoint of p-AP solubility, it is
very stable - life measured in _years_ without a change in activity.
Note that the sulfite concentration in the "Rodinal" stock is quite
high, affording complete protection from small amounts of oxygen in the
bottle. (The NA/K bisulfite concentration is 1.35 M.) Also, due to the
high developer concentration, a small fixed amount of oxidation will
only affect a small percentage of the total developer. In a dilute
solution, an equivalent amount of oxidation (moles) has a greater %
effect.
4) Acidification of p-AP may not "protect" it as well as expected. The
diaminophenol, Amidol, is still quite reactive in neutral and acidic
solutions.
The question of course, is why development is so slow for your
formulation. Assuming there are no errors and the developer is pure,
one explanation is that "B" solution has absorbed carbonate, decreasing
the pH, and/or the p-AP in the "A" solution has started to oxidize.
But I don't think that's the problem, nor the lack of agitation.
"Rodinal" is often used with an inversion every couple of minutes to
give high acutance, with little effect on overall developing time. This
is also the case when 50 g/l sulfite are added to promote more even
development and to decrease aerial oxidation.
Since the developer is exposed to air, I wonder if your developer is
oxidizing more quickly than expected due to the excess NaOH (and borax)
in the final brew in comparison to "Rodinal" ?
The low sulfite concentration in the working solution offers no
protection, and the higher pH will favor more rapid oxidation. The pH
difference should be approximately 1.4 comparing "home brew' to
"Rodinal".
p-AP is known to be very unstable at very basic pH's, which is the
reason for the titration. That might be another reason why metol was
selected for use in more active developers such as those required for
papers.
There are other alternatives to dilute "Rodinal" or "home brew", such as
Beutler's which uses metol and a higher sulfite concentration, dilute
PMK, or a dilute active developer, such as DK50 1:10. For the most
part, the acutance is determined by exhaustion of developer at low
limiting concentrations and replenishment in the emulsion, not by
agitation per se.
I've used a number of dilute developers in the manner which you
described to try to get N+ development with high acutance. In most
instances, the experiments were artistic failures since high value
separation was poor, and contrast increase was limited by the agent
used. The dilute active developers were better, but large volumes were
used to prevent overall exhaustion rather than exhaustion confined to
the emulsion.
BTW, I noticed that the "new" Agfa Rodinal didn't contain the
precipitate which the old stuff once did. It required quite a bit of
bisulfite to back titrate to the "correct" pH, but it is stable there.
I wonder if Agfa tossed in excess base to keep the machinery from
clogging up or to save a step, and ended up tossing out the underlying
rationale for the formula? (Final score: bean counters 1, photogs, 0.)
Richard Knoppow
bg...@FreeNet.Carleton.CA (Michael Gudzinowicz) wrote:
>
Lots and lots of interesting stuff snipped...
>
>
>The contact dermatitis was described by the early 1900's along with
>"remedies". Other agents, such as phenidone (Bogisch, 1889) were
>available then. The trend to avoid metol contact appears to be driven
>by the legal system, which accounts for the popularity of PQ developers
>in school darkrooms. And of course, one can develop allergies to them
>(Q) or have an M allergy triggered by exposure to a PQ developer. It's
>a nice idea to be "safe", but PQ, p-AP, etc., isn't the route. These are
>all reactive compounds which can modify cellular consituents, turning
>them into haptens.
>
Is the attribution of Phenidone to Bogisch an error? It is usually
attributed to Kendall c.1940. If it was indeed discovered in 1889
Ilford had some luck getting a patent on it. Wouldn't be the first
time that sort of thing has happened.
I have read elsewhere that the contact dermatitis caused by Metol is
from the agent itself and not from p-phenylenediamine or other
impurity as is popularly thought. I wish I could remeber the
reference.:-(
John Sparks
Michael Gudzinowicz (bg...@FreeNet.Carleton.CA) wrote:
>The contact dermatitis was described by the early 1900's along with
>"remedies". Other agents, such as phenidone (Bogisch, 1889) were
>available then...
Everything I've seen says phenidone was discovered as a developing agent
rather recently (around 1950 if I remember right).
>One question which should be asked, is whether "bromide" is responsible
>or whether rather poor buffering and agitation are the culprits. Since
>the bromide development product released is HBr (hydrobromic acid), a
>poorly buffered developer with an agent sensitive to pH may result in
>local problems. If "bromide drag" is actually due to bromide, the
>inclusion of a very small amount of bromide restrainer will completely
>mask the small local concentration and its effect. I don't think that
>bromide will affect streaking seen with poorly agitated pyro staining
>developers, which are very sensitive to pH changes.
Everything I've read says that phenidone is not restrained by bromide
which also indicates that "bromide drag" is not really accurate at least
with phenidone based formulas (though I would guess might still apply in
PQ formulas).
I would also guess that with any developer diluted enough that the rate
of diffusion is greater than the rate of development, agitation shouldn't
make much difference in development uniformity (though this will reduce
film speed and increase grain if I understand the theory right).
>(Just a comment - not everyone would agree that TMX requires
>compensation, and the -1 grade or so highlight compensation achieved
>with PMK and VC papers has turned some people off. Traditionally, many
>pros & art photogs like Ektapan, TXP and PXP in HC110 A/B or DK 50 to
>_expand_ high values.)
I definately don't want reduced hightlight contrast and have been using
TMX in TMRS 1:9 and printing on low grades of the old Multigrade FB to
increase relative highlight contrast (though I need to start looking for
a different combination since the MG IV FB has lower hightlight contrast
than the old stuff).
Rest of a very interesting analysis deleted.
John Sparks
Richard Knoppow
spa...@col.hp.com (John Sparks) wrote:
>Michael Gudzinowicz (bg...@FreeNet.Carleton.CA) wrote:
>
>>The contact dermatitis was described by the early 1900's along with
>>"remedies". Other agents, such as phenidone (Bogisch, 1889) were
>>available then...
>
>Everything I've seen says phenidone was discovered as a developing agent
>rather recently (around 1950 if I remember right).
>
>>One question which should be asked, is whether "bromide" is responsible
>>or whether rather poor buffering and agitation are the culprits. Since
>>the bromide development product released is HBr (hydrobromic acid), a
>>poorly buffered developer with an agent sensitive to pH may result in
>>local problems. If "bromide drag" is actually due to bromide, the
>>inclusion of a very small amount of bromide restrainer will completely
>>mask the small local concentration and its effect. I don't think that
>>bromide will affect streaking seen with poorly agitated pyro staining
>>developers, which are very sensitive to pH changes.
>
>Everything I've read says that phenidone is not restrained by bromide
>which also indicates that "bromide drag" is not really accurate at least
>with phenidone based formulas (though I would guess might still apply in
>PQ formulas).
>
>I would also guess that with any developer diluted enough that the rate
>of diffusion is greater than the rate of development, agitation shouldn't
>make much difference in development uniformity (though this will reduce
>film speed and increase grain if I understand the theory right).
>
>>(Just a comment - not everyone would agree that TMX requires
>>compensation, and the -1 grade or so highlight compensation achieved
>>with PMK and VC papers has turned some people off. Traditionally, many
>>pros & art photogs like Ektapan, TXP and PXP in HC110 A/B or DK 50 to
>>_expand_ high values.)
>
>I definately don't want reduced hightlight contrast and have been using
>TMX in TMRS 1:9 and printing on low grades of the old Multigrade FB to
>increase relative highlight contrast (though I need to start looking for
>a different combination since the MG IV FB has lower hightlight contrast
>than the old stuff).
>
>
>Rest of a very interesting analysis deleted.
>
>John Sparks
A note on "bromide drag". I've encountered this streaking effect
when developing 8x10 sheet film in print drums using a Unicolor motor
to do the agitation. There does not seem to be enough turbulence in
the drum to counteract the lack of sideways agitation. I not rock the
tank sideways buy hand every so often. I've gotten it with both D-76
1:1 and with Rodinal 1:25 and 1:50.
This effect is well known and is described in old Kodak literature.
It can be produced when film is developed on conventional hangars
without agitation and has been a problem in the past with
motion-picture film developing where it is manifest as a directional
streaking in the direction of the film motion in the processing
machine. Meese and others point out that the effect is caused by
developer reaction products and can be either a restraining or
accelerating effect. The reaction products of Hydroquinone, for
instance, can be accelerators.
Old literature suggests mixing a little old developer with new
developer when renewing. Modern color developing systems include a
developer "starter" which seems to accomplish the same purpose.
Michael Gudzinowicz
Richard Knoppow <dick...@ix.netcom.com> writes:
>bg...@FreeNet.Carleton.CA (Michael Gudzinowicz) wrote:
>
>>
> Lots and lots of interesting stuff snipped...
Unfortunately, I left a lot of stuff out. When I mentioned
"neutralization" by NaOH in the tables, it was for bookkeeping
purposes. In fact, the p-AP self-ionizes to a small degree (the
phenoxide is a weak acid and the amino group, weak base), and all of the
bisulfite isn't converted to sulfite. There is a pH dependent equiliria
between the bisulfite-sulfite pair similar to that of the "free base"
and phenoxide.
>>The contact dermatitis was described by the early 1900's along with
>>"remedies". Other agents, such as phenidone (Bogisch, 1889) were
>>available then. The trend to avoid metol contact appears to be driven
>>by the legal system, which accounts for the popularity of PQ developers
>>in school darkrooms. And of course, one can develop allergies to them
>>(Q) or have an M allergy triggered by exposure to a PQ developer. It's
>>a nice idea to be "safe", but PQ, p-AP, etc., isn't the route. These are
>>all reactive compounds which can modify cellular consituents, turning
>>them into haptens.
>
> Is the attribution of Phenidone to Bogisch an error? It is usually
>attributed to Kendall c.1940. If it was indeed discovered in 1889
>Ilford had some luck getting a patent on it. Wouldn't be the first
>time that sort of thing has happened.
Bogisch was granted the patent for the manufacture of phenidone in 1889,
and he studied its developing properties at that time. The Ilford
patent was for a different synthetic procedure to manufacture phenidone
(around 1951). I can't place the 1940 Kendall paper, though Neblette
alludes to a 1935 paper which dealt with structure activity
relationships. His conclusions would cover phenidone, and I assume he
was aware of the Bogisch patent.
> I have read elsewhere that the contact dermatitis caused by Metol is
>from the agent itself and not from p-phenylenediamine or other
>impurity as is popularly thought. I wish I could remeber the
>reference.:-(
Unlike poison ivy, the allergic reaction to metol and other agents
requires sensitization. What probably occurs is that the agent tightly
binds with a large biomolecule (protein, etc.) or reacts with it, so
that immune system recognizes the combination as "foreign", and mounts a
defense. Upon subsequent exposures, the developer (free or bound) or
oxidation products set off the response. p-Phenylenediamine has other
problems associated with it, the most notable being that it is a skin
carcinogen.
Michael Gudzinowicz
I thought I'd post a clarification to my long post on the subject of
para-aminophenol (p-AP), real "Rodinal", and equilibria, since a number of
people have sent me notes, and my ISP is slow in updating the newsgroups.
On the Discovery of Phenidone:
Bogisch received the patent for its manufacture in 1889, and explored its
use as a developer at that time. I don't know what he actually did with
it, but that might be interesting to explore. The patent number was
53,834 (Ger.). He synthesized it by reacting phenylhydrazine with
beta-chloroproprionic acid.
In 1951 and 1952, Ilford got patents on an _alternate_ synthetic pathway
for phenidone, not on the compound's use as a developer which was already
known (they didn't "discover" it). The patents were 650,911 and 669,591
(Brit.; Kendall & Duffin to Ilford). They used an acid hydrolysis of
3-amino-1-phenylpyrazoline.
On p-Aminophenol Stability:
The aminophenols have different properties from other developing agents
such as pyro and hydroquinone. With most of the non-amino developing
agents, one, or usually both, phenol groups must be ionized to give an
active species capable of reducing Ag+, and being oxidized by oxygen.
Assuming they reach full activity and ionization by pH 9 or so, lowering
the pH by one unit reduces the ratio of ionized to non-ionized developing
agent by a factor of ten. Dropping the pH from 9 to 5, reduces activity
by 10,000 fold, and effectively inhibits development and oxidation by air.
It also follows that the parent compounds in powder form are relatively
stable in air, while the phenoxide salts are not.
In the case of p-AP, both the phenoxide anion and the "free base" react
with oxygen. In a "neutral" solution, the "free base" can form a
zwitterion which is capable of being oxidized at pHs lower than that
required for phenoxide formation. The ring is supposed to aromatic, but
this is ASC:
__ __
/ \ + / \ -
H2N- -OH <-> H3N - -O
\__/ \__/
"free base" "zwitterion"
For future reference, these compounds will be represented as:
+ -
H2N-(AP)-OH and H3N-(AP)-O
-
The phenoxide anion will be represented by: H2N-(AP)-O
The instability of the solid free base was recogized in the 19th century,
and one may presume that in the crystals/plates the compounds exhibit some
ionic behavior as salts, linked up head to tail or overlying each other.
By donating a proton to the neighbor's amino group, the phenol was ionized
to some degree, and could react with oxygen. The solution to stability
was simple - precipitate the compound as a hydrochloride salt, which ties
up the amino group:
- +
Cl H3N-(AP)-OH
p-aminophenol hydrochloride
Likewise, diaminophenol (Amidol) is prepared as the hydrochloride. Metol
is supplied as the sulfate, which is composed of one molecule of sulfuric
acid sharing protons with two molecules of monomethyl-p-aminophenol:
+ -- +
HO-(AP)-NH2 SO4 H2N-(AP)-OH
| |
CH3 CH3
monomethyl-p-aminophenol sulfate (Metol, Elon, etc.)
Two Part Developers or Why p-Aminophenol Isn't Pyro...
In the two part formulations, such as PMK, the pyro aerial oxidation rate
is suppressed by adding bisulfite or metabisulfite to the solution, which
makes it acidic lowering the phenoxide ion and reaction rate to extremely
low levels. The inclusion of bisulfite also offers some protection by
reacting with the small amount of oxygen in the closed bottle.
There is a problem when that approach is used with a developer's acid salt.
In solution, bisulfite is in equilibrium with sulfurous acid and sulfite:
SO2 (gas) + H20 <-> H2SO3 (sulfurous acid)
H2SO3 + KOH <-> H2O + KHSO3 (potassium bisulfite)
KHSO3 + KOH <-> H20 + K2SO3 (potassium sulfite)
One should note that commercial "sulfurous acid" is really SO2 dissolved
in water to a concentration of around 6%. In other words, very very
little is present as H2SO3, if any at all - it is more of a convenient
postulate. In that respect, it is very different from sulfuric acid.
The metabisulfite used is a dehydration product of the bisulfite:
K2S2O5 + H2O -> 2 KHSO3
The problem arises with the addition of the acid developer salt:
- +
Cl H3N-(AP)-OH <-> HCl + H2N-(AP)-OH
H2N-(AP)-OH + HCl + KHSO3 <-> KCl + H2N-(AP)-OH + H2SO3
A couple of possibilities exist:
1) H2N-(AP)-OH (free base) comes out of solution as HCl is neutralized
2) H2SO3 -> H2O + SO2 (gas) = sulfite loss by SO2 release
+ -
3) H2N-(AP)-OH <-> H3N-(AP)-O = developer oxidation
+ -- +
4) 2 H2N-(AP)-OH + H2SO3 <-> HO-(AP)-NH3 SO3 H3N-(AP)-OH
#1 is observed in traditional Rodinal preparation; #2 happens and #3 may
occur if the solution is exposed to air for a long time. Our sulfurous
acid is somewhat ephemeral, but could form ammonium sulfite salts,
however, those described in the literature aren't very stable.
It would be nice if the sulfur dioxide stayed in solution to form the salt
and stabilize the free base, but anyone who has added bisulfite to
acid solutions is well aware of the out-gassing of SO2. The overall
effect is to reduce the acid concentration in the solution, permitting
free base to form, the zwitterion, and p-AP oxidation products. Adding
excess bisulfite doesn't help the problem (HCl is used to neutralize the
weak base), and precipitation may eventually occur as well as oxidation.
If one considers two-part metol developers such as Beutler's, the stock
uses sulfite at a fairly high concentration to inhibit oxidation, and to
reduce metol which has been oxidized. Similar solutions are very stable -
D23 lasts a long time even when used in a tank. The sulfuric acid in
metol appears to reduce the pH below that of a plain sulfite solution, and
yet it is active, unlike hydroquinone and pyro. Fortunately, the agent is
more resistant to aerial oxidation than the other aminophenols, and
usually gives better speed, especially when combined with a "contrasty"
agent such as hydroquinone.
Likewise, the traditional Rodinal preparations relied on high sulfite
and developer concentrations compared to very little oxygen (none) in the
sealed glass bottle. For a number of reasons, that is the most convenient
form, and sulfite is used for protection from oxidation, not low pH.
Although the "Rodinal" preparations differ, titration of a dissolved
concentrate with bisulfite to where the p-AP just starts to come out of
solution, gives stable solutions if kept in sealed glass bottles. I have
a couple of samples treated that way in 1991-93, and there has been no
reduction in activity.
Michael Gudzinowicz
John Sparks <spa...@col.hp.com> writes:
>Michael Gudzinowicz (bg...@FreeNet.Carleton.CA) wrote:
>
>>The contact dermatitis was described by the early 1900's along with
>>"remedies". Other agents, such as phenidone (Bogisch, 1889) were
>>available then...
>
>Everything I've seen says phenidone was discovered as a developing agent
>rather recently (around 1950 if I remember right).
Somewhere in the thread, I posted an "explanatory" note which has the
patent dates and numbers. The date was 1889, cited in the Merck Index
and the Focal Encyclopedia.
>>One question which should be asked, is whether "bromide" is responsible
>>or whether rather poor buffering and agitation are the culprits. Since
>>the bromide development product released is HBr (hydrobromic acid), a
>>poorly buffered developer with an agent sensitive to pH may result in
>>local problems. If "bromide drag" is actually due to bromide, the
>>inclusion of a very small amount of bromide restrainer will completely
>>mask the small local concentration and its effect. I don't think that
>>bromide will affect streaking seen with poorly agitated pyro staining
>>developers, which are very sensitive to pH changes.
>
>Everything I've read says that phenidone is not restrained by bromide
>which also indicates that "bromide drag" is not really accurate at least
>with phenidone based formulas (though I would guess might still apply in
>PQ formulas).
Probably not PQ either... If you consider hydroquinone alone, it
certainly isn't restrained by the bromide it generates when developing
high density areas. I don't know if its seemingly inexhaustible energy
is due to Q per se, or the formation of more active products. Undiluted
Microphen certainly has good acutance.
>I would also guess that with any developer diluted enough that the rate
>of diffusion is greater than the rate of development, agitation shouldn't
>make much difference in development uniformity (though this will reduce
>film speed and increase grain if I understand the theory right).
I was rambling in my first reply just to point out that the sacred
simple explanations and catch phrases are like black holes from which
there is no return (much like trying to explain why 100 years ago,
p-aminophenol was dumped as a general agent (like metol) and Rodinal was
used instead).
I think the primary mechanism is local developer exhaustion in the
emulsion. There is a laminar layer on the film surface which can slow
down transfer, but with reasonable agitation, it will have little effect
on what happens in the emulsion matrix. One still sees edge effects
with frequent agitation.
Although a lot of people don't like the idea of surface developers, when
I started to use replenished Agfa 17 in tanks, I read some of the
literature on the developer. One of the first journal articles I found
contained micrographs showing that almost all development was confined
to the surface of the emulsion - Agfa 17, a MQ clone with bromide added
was being used as the surface developer in controlled experiments.
To get complete or "non-surface" development, one has to go to a
developer like D-11. When it is used, everything above the threshold is
developed, but there are _no_ edge effects. In fact, it is used as a
control developer when scanning edges for adjacency effects... 100 %
contrast rolling off at the edge with no boost.
What I think is happening with high acutance developers, is rapid
oxidation by silver at the surface. Products will diffuse in all
directions, including toward the base until an equilibrium is
established between the surface area and deeper areas, effectively
counteracting that "early" gradient. At that point, the products might
restrain any active developer which gets past the surface area. The
gradient for product dilution will be from the surface area to
developer, and likewise replenishment will occur primarily at the
surface. The surface area is really the only region where product
removal and replenishment is significant.
The edge effect may occur by active developer diffusion _in_ the
emulsion from areas where little development has taken place to higher
density areas (down a concentration gradient), while products diffuse
into the low development area from the "edge" area. Since the
adjacent low density area doesn't add to the product concentration, the
gradient is downhill to that area, and out of the emulsion. Therefore,
the edge of the high density area acts like the surface to some degree,
and permits more development and deeper development of the edge.
solution **** = areas where high
high low density silver
density density development
___________________________________ surface occurs
gel ********* edge
* * <- active
equilibrium developer
<- products -> diffusion
diffusion
___________________________________ base
>>(Just a comment - not everyone would agree that TMX requires
>>compensation, and the -1 grade or so highlight compensation achieved
>>with PMK and VC papers has turned some people off. Traditionally, many
>>pros & art photogs like Ektapan, TXP and PXP in HC110 A/B or DK 50 to
>>_expand_ high values.)
>
>I definately don't want reduced hightlight contrast and have been using
>TMX in TMRS 1:9 and printing on low grades of the old Multigrade FB to
>increase relative highlight contrast (though I need to start looking for
>a different combination since the MG IV FB has lower hightlight contrast
>than the old stuff).
I don't use the IV, so I've avoided the problem until MGFB runs out.
The IV curves I saw indicated a relatively straight line response for
the paper. I wonder if part of the problem was the use of older VC
papers with contrasty negatives requiring lower grades. Often, the low
values responded more to filtration than the highs, so a selective high
value contrast boost could be achieved. It was very apparent with old
Polyfiber, with which high value contrast hardly would budge with
filtration. If films were developed for the same contrast to match
paper high values, the highs always looked good, while the low end
contrast could be adjusted for negative under-exposure if required.
If the problem is paper's toe, adding some 10% bromide and extending
exposure and development should get rid of the toe, and 10% carbonate
can be used to recover some developer activity (Lootens approach).
Another alternative is graded papers - they do look nice. One can boost
their high values by using G5 paper with a ferricyanide pre-bleach which
David Kachel described in D&CCT a few years ago. Tossing more Q into
the developer may work, but I'd try to deal with the paper first.
JCarb94670
Your formula looks very interesting, have you tried substituting Sodium
Hydroxide with Trisodium Phosphate?
Let me know how it turns out
Jim Carbone
JC...@juno.com
JCarb94670
That is a very interesting formula but I have one question? Why no
bromide? I have always needed bromide as a restrainer. How do you over
come the fogging with Sodium Hydroxide? This developer can only be used
one shot. I have made a lot of statements without really trying it. But
that was my first impression, I believe it needs a few more ingrdients.
Lets Talk
Jim Carbone
jc...@juno.com