Adox MQ Borax Formula.

I have read two different formulas for the Adox MQ Borax fine grain
developer, one gives one gramme per litre and the other gives two grammes
per litre, which one is the official Adox formula?
Also, was there a replenisher formula for this?

 

The Adox formula is just a mior variation of D-76.

It uses 80 g/l of sulfite instead of 100, and uses 0.5 g of bromide.

That is the nmain difference.

http://www.subclub.org/darkroom/develop2.htm

http://www.catslab.com/photo/formules/form_f_00.html

 

That sounds like the old Agfa 17 formula.

Agfa/Ansco 17

Water (at 125F or 52C) 750.0 ml
Metol 1.5 grams
Sodium sulfite, dessicated 80.0 grams
Hydroquinone 3.0 grams
Borax, granular 3.0 grams
Potassium bromide 0.5 gram
Water to make 1.0 liter

80 grams of sulfite per liter is probably closer to the
optimum than the 100 grams in D-76, not a big deal. In their
1929 paper on D-76 Carlton and Crabtree (of Kodak Labs)
tried about 30 variations of D-76 including one with a small
amount of bromide in it. They used 0.75 grams/liter. The
results were a slight increase in film speed due to
reduction of the slight fog that _unused_ D-76 produces.
When the developer is used some bromide comes out of the
film so used developer or replenished developer has bromide
in it. Carton and Crabtree's paper announced the buffered
version of D-76. The buffering was to eliminate a slow
increase in activity of the developer over time. Carlton and
Crabtree did not know what caused the rise other than it was
associated with an increase in pH. It turns out that this
was due to a slow reaction between the Hydroquinone and
Sulfite, which produces some Sodium hydroxide. It also
produces some reaction products of Hydroquinone which are
active developers, but they are not active at the relativly
low pH of D-76 so are not part of this problem. Current
packaged D-76 is the buffered variety. It would be possible
to buffer the Agfa formula by adding Sodium bisulfite (or
metabisulfite) in the correct amount.

The following is the replenisher formula for Agfa 17

Agfa 17 Replenisher
Water (at 125F or 52C) 750.0 ml
Metol 2.2 grams
Sodium sulfite, dessicated 80.0 grams
Hydroquinone 4.5 grams
Borax, granular 18.0 grams
Water to make 1.0 liter

Add 15ml to 22 ml of replenisher for each 80 square inches
of film developed (equivalent to one roll of 120 film or one
36 exposure roll of 35mm film).

 

Similar to the Agfa formula, but distinct.

 

* Metol :- 2 grammes
* Sodium Sulphite, anhydrous :- 80 grammes
* Hydroquinone :- 4 grammes
* Borax :- 4 grammes
* Potassium Bromide :- 0.5 grammes
* Water to :- 1000ml.

This is a variation of D-76 that gives slightly better sharpness but
development times must be increased by 10 - 20 %.

http://www.cjballphotography.org.uk/formulae.html#formulae

Glenn Booth

 

That formula agrees with the one in P. Dignan's Classic B&W Formulas.

 

Nearly every film manufacturer published some version of
D-76, usually with some small variation to make his own.
From research done recently by Ryuji Suzuki it appears that
the Agfa formula is slightly superior to the original Kodak
formula but it would be difficult to see it in practice. I
have taken to adding 0.5 gram /liter of Potassium bromide to
D-76. I _think_ this is giving me slightly cleaner
negatives. I use D-76 diluted 1:1 as a one shot. As
mentioned in my other post bromide accumulates in reused or
replenished developers so, if you work that way, adding
bromide is useful only as a "developer starter" to get the
system to equilibrium a bit faster.
There are an enormous number of developers which can be
seen as D-76 derivitives. Among them similar developers
using Metaborate in place of Borax, or Phenidone in place of
Metol (Microphen).
Even Xtol can be seen as a D-76 type developer where
Metaborate replaces the Borax buffer, and a Phenidone
(actually Kodak Dimezone-S) and Ascorbic acid replace the
Metol-Hydroquinone system.
D-76 has been around since 1927 when it was first
published as a fine grain developer for duplicating motion
picture negative films. In 1929 an extensive paper was
written by Crabtree and Carlton of Kodak Labs describing a
large number of variations and introducing the buffered
version. It has remained the standard of comparison for B&W
negative developers ever since. D-76 is attributed to John
G. Capstaff, of Kodak Labs, who also worked out the methods
for reversal processing that made 16mm home movies
practicable.

 

I wonder if anyone has tried this and can confirm either
statement. The developer is more active than D-76, not the
double amount of Borax and there is nothing in it to suggest
is produces more edge (acutance) effects.

 

The lower amount of sulphite is supposed to reduce the loss of
definition due to sulphite solvency. That's what Crawley claims. The
presence of a small amount of bromide may also contribute to better
sharpness than straight D-76, if I recall correctly.

 

Interesting. The action of sulfite is to dissolve a small
amount of the surface of each silver grain. Where the action
is limited, as in D-76, D-23, etc, the effect is raise film
speed slightly because it exposes more development centers
to the developer. High sulfite also affects the shape of the
developing silver crystals. All this has little effect on
resolution.
We should be careful to distinguish resolution from
sharpness, they are not the same. Resolution is a measure of
the ability of the film to record fine details. The
resolution limit is determined for some fixed contrast
between the dark and light adjacent lines. Most film
resolution numbers, as given by manufactuers, is for high
contrast targets, 1:1000, Kodak also gives values for low
contrast (typically 1:30 brightness ratio) targets. The
limiting factor for resolution is usually the amount of
scattering to light in the emulsion, an effect known as
irradiation. Modern films, which have relatively thin
emulsions, have less scattering, hence higher resolution,
than the films of the past.
Sharpness is a perceived quality. To a large extent it is
independant of resolution. The eye judges sharpness largely
by the contrast at the demarcation of light and dark areas.
If the transition is sharply defined the eye intreprets it
as meaning the image is sharp. It is possible to have high
resolution images which do not appear sharp because the edge
contrast is low and vice-versa. Kodak Labs did a lot of
research on perceived sharpness and came up with the term
Acutance to indicate the effect. Acutance can be improved by
a developer which exagerates the contrast at edges. This is
known as the adjacency effect, also called edge effects. It
has to do with the generation of development reaction
products at the transition of a high and low density area.
Right at the edge of a high density area there are a lot of
reaction products. They move in the emulsion by diffusion.
Where conditions are right these products diffuse sidways
into adjacent areas of the image affecting the way they are
developed. Right at the edge of a high and low density area
there is a relatively low concentration of these products so
the edge tends to be developed more than the body of the
dense are. Essentially, this draws a line around objects in
the image. This is a simplification of the effect but will
give some idea of what is happening.
The amount and nature of acutance effects depends on the
developer and amount of development, etc. One of the main
functions of sulfite is to preserve the developer by
recombining the reaction products into either active
developer or to a form which has no effect on development.
The more sulfite the less acutance effect. Developing agents
also behave differently. For instance, the reaction products
of Metol are not active developers. Also, Metol is not very
sensitive to bromide. Hydroquinone, OTOH, is very sensitive
to bromide and its reaction products are very active
developing agents, at least at high enough pH. In D-76 and
D-23 type developers the pH is too low for either
Hydroquinone or its reaction products to be active as
developers, but the Hydroquinone still has the effect of
regenerating the Metol, which tends to limit adjacency
effects, and thus, acutance.
So called high-acutance developers are those which allow
an exagerated amount of adjacency effect. They are typically
low sulfite and have a single developing agent. For
instance, Rodinal is a good acutance developer at high
dilutions. Developers like D-76 and D-23 begin to produce
adjacency effects at high dilutions because the
effectiveness of the sulfite is diminished. At dilutions of
1 part developer to 3 parts water both of these (and
Microdol-X and D-25) become acutance developers.
Although there is not much measurable difference between
the resolution of high and low acutance developers the
adjacency effects necessary for high acutance tend to smear
very fine details so high acutance developers are not a good
choice where maximum resolution is desired.
The idea that sulfite somehow dissolves the fine details
is wrong and is based on a mistaken idea about how sulfite
functions in the developer.
Note that the scale of the adjacency effect is fixed. It
will have relatively large effect on small formats, mainly
35mm film, and little on larger sizes. At 4x5 it is probably
undetectable in the image.
Note also that the conditions for producing acutance are
not compatible whith those for fine grain. However, a
compact, sharp, grain pattern will also lend the illusion of
sharpness. One can prove this effect by printing a sharp
grain pattern over a print of a blurry negative.

 

Then the formula which say`s 2 grammes per litre, is probably the official
Adox formula. I had not seen a replenisher formula for this developer before
either, so a formula for me to file for future reference.
Thankyou, to all who replied.

 

I know all of this, Richard. Perhaps 'definition' is higher with the
lower sulphite.

See BJ Photo Annuals from the late 60s-early 70s.

 

The sulfite does not dissolve metalic silver.
I does have some small solvent effect on the
silver halides.
If the order of solvency, from chloride, bromide,
then iodide is, as I think likely, the same as that
of ammonia and thiosulfate, then the effects of varying
sulfite levels should be most visable with print paper.
An all chloride paper such as AZO should, more than
any other paper, show the effect of changing
sulfite levels.
I hope to do some experiments doing just that.
BTW, you don't happen to know if ascorbic acid acts
as a silver halide solvent? Dan

 

ascorbic acid will reduce silver salt to metallic silver even at pH 4
(slowly) and much faster at pH 7 and above.
Silver nitrate in acidic solution is used in biology to find
"deposits" of ascorbic acid in plants.



On 25 Aug 2005 16:06:48 -0700, wrote:

*RE:Richard Knoppow wrote:
*>
*> The action of sulfite is to dissolve a small
*> amount of the surface of each silver grain.
*>
*
* The sulfite does not dissolve metalic silver.
*I does have some small solvent effect on the
*silver halides.
* If the order of solvency, from chloride, bromide,
*then iodide is, as I think likely, the same as that
*of ammonia and thiosulfate, then the effects of varying
*sulfite levels should be most visable with print paper.
*An all chloride paper such as AZO should, more than
*any other paper, show the effect of changing
*sulfite levels.
* I hope to do some experiments doing just that.
* BTW, you don't happen to know if ascorbic acid acts
*as a silver halide solvent? Dan

 

That's what he meant.

 

Thanks for pointing out the error, I left out the word halide :-(.
The point of my post was as you point out, that sulfite does not
dissolve metallic silver but rather has an effect on the undeveloped
silver halide. This can affect the way the halide builds into metallic
silver crystals as it develops buth the "salt effect" that is the
reduction of emulsion swelling from large amounts of sulfit is also an
important factor in fine grain development.

 

Thankyou to all who replied to this thread.