D23 = Microdol-X ?
SPECTRUM
I find don't think it would be very likely that microdol - X would be a
derivative of D-23. At least not the original Microdol. More likely a
p-phenylene diamene derivative. Everyone that I've talked to seems to agree
that D-23 gives good sharp, and fine grained negs. But Microdol has never
been know as a "sharp" developer. Also most specs state that Microdol will
cost .5 - 1 stop in film speed where D-23 doesn't cost film speed at all.
Of course their is another possiblilty , It _could have been a combo of
_both_ p.p.d. AND Elon. Just a thought :)
--
Regards,
John S. Douglas
Spectrum Photographic Inc.
1- 908 - 505 - 8393
http://www.cybercomm.net/~spectrum
!! World Field Photographers Association !!
"For the photographer who likes to live large ! "
http://www1.tip.nl/~t487331/frame.htm
Richard D Rinehart wrote in article <5vff2p$c5u$1...@gte1.gte.net>...
>Sun Demon <ki...@usa.net> wrote in article
><341b288b...@news.iperbole.bologna.it>...
>> I think I've read something about Microdol-x being a similar developer
>> to D23.Who knows the Microdol-x formula?
>
> I may be mistaken but I believe Kodak still holds a patent on Microdol-X
>as a proprietary formula and from past experience with Kodak on technical
>matters I doubt that they would even acknowledge even speculation on their
>formulas.
> However I have a formula on file that is reputed to be Microdol-X, however
>I cannot confirm that it is so I will post it and invite discussion on
>whether you think it might be or not, I don't care for Microdol-X because
>the high concentration of Sodium SulFITE ** (caps for emphasis) makes it a
>silver halide solvent developer, but you might care for it and find a use
>for it.
> I also include the formula for D-23 in case you don't have it.
>
>
> MICRODOL-X
> D-23
>
>HOT Water (125 F) to MIX....................750.00
>mls.....................750.00 mls
>
>Metol (or Elon)........................................6.00
>g............................7.50 g
>
>Sodium SulFITE** (anhydrous)..............150.00
>g........................100.00 g
>
>Potassium Bromide.................................1.00
>g...........................0.00 g
>
>COLD Water to make.........................1000.00
>mls..................1000.00 mls
>
>
> Here are the two formulas side by side and I hope the news server does not
>scramble them around, as a personal preference I would use these formulas
>on the older type films (Plus-X, Tri-X, FP-4, HP-5, etc) and not on the
>tabular grain films (T-Max and the Delta films), but this is personal
>and your choice entirely.
>
>
>Richard D Rinehart
>Photochemist
>
>photoc...@juno.com
>
>
>
>
>
>
>
>
>
>
>
>
>
>
Sun Demon
Rick Ellis
In article <5vff2p$c5u$1...@gte1.gte.net>,
Richard D Rinehart <ami...@gte.net> wrote:
> I may be mistaken but I believe Kodak still holds a patent on Microdol-X
>as a proprietary formula and from past experience with Kodak on technical
>matters I doubt that they would even acknowledge even speculation on their
>formulas.
Microdol-X was around in the 60's at least. How could Kodak still have
an unexpired patent on it?
Richard Knoppow
ki...@usa.net (Sun Demon) wrote:
>I think I've read something about Microdol-x being a similar developer
>to D23.Who knows the Microdol-x formula?
D-25 is closest to Microdol-X of the Kodak published formulas but it
is not the same. The msds for Microdol-X indicates it uses sodium
chloride restrainer and has some other differences. D-25 was intended
to duplicate the grain performance of the paraphenelyne diamine
developers popular in the 1930's without the speed loss and toxic
ingredients. It is composed of Metol working in a nearly neutral pH,
solution of Sodium sulfite and Sodium Bisulfite. Microdol-X contains
Metol, Sodium sulfite, Sodium chloride, Boron oxide, and Tri basic
Sodium phosphate according to the MSDS. There may be other non-listed
ingredients.
D-23 consists of Metol and Sodium sulfite. D-23 is supposed to be
about equal to D-76 for grain and speed. D-25 and Microdol-X are less
grainy and loose about one stop when used full strength, the speed
loss and fineness of grain both go away when they are diluted, due to
the lower solvent action of the sulfite.
D-23 and D-76 have very similar photographic characteristics. The
Borax in D-76 isn't alkaline enough to activate the Hydroquinone as a
developing agent, it functions mainly to preserve and regenerate the
Metol. As a result D-76 is much longer lived than D-23.
---
Richard Knoppow
Los Angeles, Ca.
dick...@ix.netcom.com
Michael Gudzinowicz
Sun Demon <ki...@usa.net> writes:
>I think I've read something about Microdol-x being a similar developer
>to D23.Who knows the Microdol-x formula?
If EKC ever patented Microdol-X (now expired), the patent would reveal
the composition, however, it is usually expressed as a range in patents
and the exact formula retains the air of a trade secret.
The Kodak MSDS and product package provides some information on the
current composition of Microdol-X. The MSDS gives percentage ranges for
the consituents, and the conversion to grams per liter assumes that the
1 gallon packet of Microdol-X contains 17.0 oz powder. Reversing the
estimate using know formulas for a buffered version of D-76 can validate
the approach (I've done so; data not shown).
Perentage g/l
Sodium Sulfite 70 to 80% 93 to 106 g/l
Sodium Chloride 20 to 30% 26 to 40 g/l
Metol 1 to 5% 1.3 to 6.6 g/l
Boric Anhydride - -
Sodium Hexametaphosphate - -
A reasonable starting point for experimentation would be:
Sodium Sulfite 100 g/l
Sodium Chloride 33 g/l
Metol 5 g/l
Boric Anhydride 1+ g/l
Sodium Hexametaphosphate 1 g/l
Table salt should not be used due to other halides which have a marked
effect on film speed. Use a commercial packet of Microdol-X as a
control, and add boric anhydride to acidify the clone until activities
match, checking the CI with a densitometer. BTW, develop at 75F. Note
that packaged Microdol-X and other developers are often less expensive
that the cost of photograde chemicals used to mix developers.
You can probably replenish the developer with DK-25R in a manner similar
to D-23 replenishment.
Richard Knoppow has pointed out the the original formula of the old
Microdol (not X) was a derivitve of Kodak's high sulfite DK-20 which
also contained the silver solvent sodium thiocyanate. The latter
compound may have lead to a loss of sharpness.
Comments that Microdol-X is less sharp or gives finer grain due to
silver solvent effects on grain "edges" are unfounded. To examine
silver grains requires extremely high magnification - the image seen
with a grain magnifier is a composite of clumped grains. The "grain" or
granularity in prints is due to uneven development of the negative, and
the dark print "grains" are "holes" or areas of less development in the
negative.
The low pH of fine grain developers does not remove hardeners from the
negative emulsion reducing clumping, and high neutral salt
concentrations such as those used in "tropical developers" also reduce
emulsion swelling and damage. Sodium chloride is a _very_ mild
restrainer, and along with the developer's low pH, it may be partly
responsible for the speed loss. These effects permit the developer to
have a short induction time in comparision to the time for total silver
development. Therefore, on a relative basis, more silver grains are
developed per area to give the same image density as that afforded by
more active developers, and more exposure is required. The details of
the approach to fine grain development outlined above have been in the
research literature for over fifty years, and haven't been disputed.
With respect to resolution and acutance, Microdol-X was compared to
Rodinal, D-76 and other developers by Dr. Ricahrd Henry in "Controls in
Black-and-White Photography" using reliable procedures including a
microdensitometer to measure acutance. Microdol-X was as good or better
than other developers depending upon the film tested. Note that
acutance is measured by the slope of a printed knife edge, and isn't
the "border effect" with which some people confuse it. Dilute, active,
grainy developers may give an _impression_ of sharpness, but actual
measurements will indicate that actual resolution is lost.
If you're looking for a good fine grain combination, you might try T-Max
100 (TMX) exposed at EI 25 to 32 and developed at 75F in undiluted
Microdol-X for Kodak's recommended times. Granularity is comparable to
Tech Pan, and sharpness is very close. To examine the differences
include a white plastic bag in the "scene", and print for the bag. At
high enlargements, the bag will retain a grainless sheen similar to
large format results, while other developer's granularity will "muddy"
it to give the appearance of a paper bag.
e...@clark.net
Sun Demon (ki...@usa.net) wrote:
: I think I've read something about Microdol-x being a similar developer
: to D23.Who knows the Microdol-x formula?
The formula was never published, but in action and resulting negatives,
Microdol-X is very obviously D-23's successor. Originally, Microdol
had no "X". At that time, Kodak had a recommendation for making it
an ultra-finegrain developer by adding Benzotriazole. Then came
Microdol-X, but without Benzotriazole, being called an ultra-finegrain
developer! Reading the data sheet (required for all chemicals sold
nowadays) I notice that a substantial amount of Sodium Chloride is
included! (Common salt) This may well have a weak restraining action,
thus allowing less Sodium Sulfite than in D23 to do just as much silver
halide and image silver dissolving as the larger sulfite content of
D-23. Also, it would be less toxic than Benzotriazole.
Personally, I like Microdol-X at 1:3 dilution. The negatives are
tack-sharp, with full emulsion speed instead of the 1 stop loss with
either D-23 or Microdol-X straight. There is a little more grain, but the
highlights never are blocked up. An evem better choice is to use
Ilford Microphen diluted 1:3 exactly as one would use Microdol-X 1:3,
processing for exactly the same time. The results are identical, but for
the fact that the Microphen delivers 1/3 to 1/2 stop more real (shadow)
speed. If properly exposed at about 1/3 stop higher EI, the negative from
the Microphen 1:3 will be indistinguishable from the Microdol-X 1:3
negative. If, like me, your skin is sensitive to Metol, it is safer,
also.
My $.02.
Edward M. Lukacs, LRPS
Washington, DC, USA
Scott Dorsey
In article <341b288b...@news.iperbole.bologna.it> ki...@usa.net (Sun Demon) writes:
>I think I've read something about Microdol-x being a similar developer
>to D23.Who knows the Microdol-x formula?
It's not. Microdol-X has a very high concentration of sulfite, which acts
as a silver solvent and reduces fine detail as it reduces grain. It is
a special-purpose developer intended specifically for reduced grain.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
SPECTRUM
Perhaps all of this research is contrary to my observation, which isn't
that novel. When I used Microdol-X with the 35 mm version of TX , I coudn't
find an edge in the entire image. In either the high or low contrast areas.
Just plain old mushy ! At the time I was usnig good macro lenses for most of
my work. And the grain an contrast weren't anything to write home about.
Combine that with a speed loss , EI 200, and you've got a sure fire loser.
BTW, could grain migration have been a problem with the Microdol - X ?
I may agree that a fine grain developer such as Xtol or D-76@1:1 or 1:3
will define an edge better than Rodinal but the appearance of sharpness is
much stronger with a dilute developer such as Rodinal at the 1:100 dilution.
Appearances may be decieving but that's what I look at from across the room
!
And what is boric anhydride ? Some form of boric acid ? As a buffer ?
--
Regards,
John S. Douglas
Spectrum Photographic Inc.
1- 908 - 505 - 8393
http://www.cybercomm.net/~spectrum
!! World Field Photographers Association !!
"For the photographer who likes to live large ! "
http://www1.tip.nl/~t487331/frame.htm
Michael Gudzinowicz wrote in article
<5vgaks$l...@freenet-news.carleton.ca>...
>
>Sun Demon <ki...@usa.net> writes:
>
>>I think I've read something about Microdol-x being a similar developer
>>to D23.Who knows the Microdol-x formula?
>
Davidlindq
Patents are a matter of public record. Hence it's not possible to buy up a
patent (e.g. of a carbuerator design that makes it possible to run an
automobile on water ;-)) in order to suppress the information. Though of
course manufacture by others could be prevented for the term of the patent.
A company may choose to keep something as proprietary information instead
as an attempt to maintain an exclusive opportunity to provide the product
past the time a patent would expire, e.g. the formula for Coca Cola.
Kodak's numbered formulas, e.g. D-23, are published. The named ones, e.g.
Dektol, are not. It is my understanding that Kodak may change the make-up
of their "named" chemistries from time to time without necessarily
modifying the name
David Lindquist
David...@aol.com
Sun Demon
On Sun, 14 Sep 1997 00:01:13 GMT, ki...@usa.net (Sun Demon) wrote:
>I think I've read something about Microdol-x being a similar developer
>to D23.Who knows the Microdol-x formula?
Thank you for all your answers. My new question is: is there a ready
made developer closer to D23 than Microdol-x? And:
anybody uses on a regular basis D23 for Tmax 400 and Konica ir750?
Do you agree with the very interesting article in
http://www.heylloyd.com/technicl/D23.html
???
Tim Daneliuk
I infer from reading the URL you cite above that you like D-23 because
of its ability to keep the highlights from blowing out in the negative.
I cannot comment on how close it is to D-23, having never used this
developer, however, I process Agfapan APX 100 in PMK Pyro and get
marvelous results. I have also used PMK Pyro with Tri-X and TMX, again
with very good results. I have consistently found that PMK Pyro appears
to hold the highlight detail longer than other developers like HC-110
or T-Max RS. This is, of course, a subjective call, based on observation
not rigorous testing. You might want to try this developer and see
how you like it. If you do, Hutchings' "Book Of Pyro" is a must.
--
------------------------------------------------------------------------------
Tim Daneliuk
VoiceMail/FAX 847.827.1706
tun...@tundraware.com
Jean-David Beyer
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e...@clark.net wrote (in part):
> Also, it would be less toxic than Benzotriazole.
I looked up the MSDS for this from two different manufacturers.
One said it was moderately irritating if the powder were inhaled.
The other thought it was quite harmless. I would not really want to
inhale powdered sodium chloride either. BZT is a much better restrainer
than sodium chloride. I imagine it is there for other reasons.
--
Jean-David Beyer
Shrewsbury, New Jersey
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SPECTRUM wrote (in part):
> And what is boric anhydride ? Some form of boric acid ? As a buffer ?
Boric acid is H3BO3. I would have guessed that Boric anhydride would be
HBO2; i.e., boric acid with one water molecule missing, but Eastman Organics say
it is the same as Boron Oxide, B2O3. I.e., two boric acid
molecules with three water molecules missing between them. There is also
tetra-boric acid (pyro-boric acid): H2B4O7. I assume that the boric anhydride
is more soluble than the boric acid, but did not look it up.
--
Jean-David Beyer
Shrewsbury, New Jersey
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Jean-David Beyer
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Sun Demon wrote:
> On Sun, 14 Sep 1997 00:01:13 GMT, ki...@usa.net (Sun Demon) wrote:
>
> >I think I've read something about Microdol-x being a similar developer
> >to D23.Who knows the Microdol-x formula?
>
> Thank you for all your answers. My new question is: is there a ready
> made developer closer to D23 than Microdol-x? And:
> anybody uses on a regular basis D23 for Tmax 400 and Konica ir750?
> Do you agree with the very interesting article in
> http://www.heylloyd.com/technicl/D23.html
> ???
I looked at the cited page, but am unimpressed.
There is no ready-made D-23 unless you buy it from, e.g., Photographers'
Formulary (they have a web site). I imagine Formulary Film Developer 23
is the same. They say it is similar.
I used 2-bath D-23 and D-25 with a 2% sulfite and 2% Kodalk solution
for the second bath. These worked out OK for 4164 Tri-X sheet, but
they spoil the sharpness for TMY. I also do not really care for 2-bath
developers as they spoil the shadow contrast. I prefer a straight line
all the way down to Dmin, but some people do not like it. For TMY, I
intend to use Xtol 1+1.
--
Jean-David Beyer
Shrewsbury, New Jersey
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Michael Gudzinowicz
John Douglas <spec...@cybercomm.net> wrote:
> Perhaps all of this research is contrary to my observation, which isn't
>that novel. When I used Microdol-X with the 35 mm version of TX , I coudn't
>find an edge in the entire image. In either the high or low contrast areas.
>Just plain old mushy ! At the time I was usnig good macro lenses for most of
>my work. And the grain an contrast weren't anything to write home about.
>Combine that with a speed loss , EI 200, and you've got a sure fire loser.
Perhaps, but in tests of resolving power and acutance, the combination
did far better than that in Henry's tests (there are problems inherent
in macro). I wouldn't recommend the developer for use with most fast
films, since the overexposure of TX results in scattering in the
emulsion. With D-76 or other developers which act on the surface, it
isn't a problem. With Microdol-X, you do get "deeper" development, and
it's more even, for the same reasons that one doesn't see a marked
border effect (mutually exclusive). With MF or LF the combo works
fairly well, especially with flash. Gamma in Chicago, perhaps the best
custon B&W lab, uses it as the developer of choice if speed isn't
required (D-76).
TMY at EI 160-200 with Microdol-X is a nice film for use with strobes -
highlights don't blow out, grain is smooth, and shadow detail is very
good - it beats pushing TMX. Both TMY and TMX have high iodide
concentrations which resists any solvent effects. I have exposed film
evenly, and presoaked in sulfite, chloride, ect. to try to "dissolve"
the silver or grains, and the effect is almost non-exisitent - like a 1%
change in density - far less than the 1 stop loss erroneously attributed
to the "solvent effect".
With TMX and TMY, there doesn't appear to be any loss of sharpness - in
fact, in my tests, it has better resolution than other developers with
TMX. I use it with MF TMX and strobe lit TMY, and on occasion, with 4x5
TMX if I really need smooth tonality.
> BTW, could grain migration have been a problem with the Microdol - X ?
No - the low pH and high salt concentration prevents it. One the other
hand, fast films do require very long development times with Microdol-X,
etc., so there may be some migration compared to slow films or new
formulations. That's speculation, but I think it's well founded.
> I may agree that a fine grain developer such as Xtol or D-76@1:1 or 1:3
>will define an edge better than Rodinal but the appearance of sharpness is
>much stronger with a dilute developer such as Rodinal at the 1:100 dilution.
>Appearances may be decieving but that's what I look at from across the room
>!
It just depends upon what you want. DK50 at 1:10 (not a great looking
dilution) developed for a while, gives a marked border effect -
something like 150% increase in density at the border. However,
anywhere in the image where the exposure or silver halide distribution
is uneven, the differences are emphasized resulting in more granularity.
I don't use 35 mm fast films often, but when I do, I ususally prefer
grainy developers if I know the enlargements are large - others often
are blotchy, and sharp "grain' covers all sorts of errors. For the
smooth 8x10 contact look, I often use Microdol-X, TMX and MF/LF instead.
It just depends on the mood, requirements and problems.
> And what is boric anhydride ? Some form of boric acid ? As a buffer ?
It is essentially a "dehydrated" boric acid, which forms boric acid
after contact with water. Sulfite is the primary buffer, and the
anhydride acts as an acid to lower the pH. The effect is similar to
using metabisulfite in the old fine grain developers, to lower the pH.
>Michael Gudzinowicz wrote in article
><5vgaks$l...@freenet-news.carleton.ca>...
>
>>
>>Sun Demon <ki...@usa.net> writes:
>>
>>>I think I've read something about Microdol-x being a similar developer
>>>to D23.Who knows the Microdol-x formula?
>>
Richard Knoppow
Jean-David Beyer <jdb...@exit109.com> wrote:
>This is a multi-part message in MIME format.
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>
>
>
>SPECTRUM wrote (in part):
>
>> And what is boric anhydride ? Some form of boric acid ? As a buffer ?
>
> Boric acid is H3BO3. I would have guessed that Boric anhydride would be
>HBO2; i.e., boric acid with one water molecule missing, but Eastman Organics say
>it is the same as Boron Oxide, B2O3. I.e., two boric acid
>molecules with three water molecules missing between them. There is also
>tetra-boric acid (pyro-boric acid): H2B4O7. I assume that the boric anhydride
>is more soluble than the boric acid, but did not look it up.
>
>--
>Jean-David Beyer
>Shrewsbury, New Jersey
>
>
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I think the Boron anhydride or oxide becomes Boric acid in solution.
Perhaps it is more stable in its un-mixed condition.
Richard Knoppow
e...@clark.net () wrote:
>Sun Demon (ki...@usa.net) wrote:
>: I think I've read something about Microdol-x being a similar developer
>: to D23.Who knows the Microdol-x formula?
>
D-25 and D-23 were developed at the same time at Kodak labs. D-23
is a variation of D-25. In fact the ratio of Sulfite to Bisulfite in
D-25 can be varied to any ratio between the two with a resulting
increase in speed and grain as it is lessened (moved toward D-23 which
has none). The difference is strictly the pH and therefore activity
of the solution. Metol can develop in a practically neutral solution
which is what D-25 is. Microdol-X was devised at about the same time.
The current Microdol-X formula may not be the original, which I
suspect was D-25 or pretty close to it.
All of these developers were devised to provide the photographer
with a practical fine-grain developer which would work with "modern"
film. D-25 and D-23 were released in about 1943 and Microdol-X around
1949.
The original Microdol is identical with publlished formula DK-20. It
contains Potassium Thiocyanate, a powerful solvent of silver halide.
In the older thick emulsion films this resulted in a noticeable
reduction of grain. With newer films the tendency of the thiocyanate
to reduce resolution and produce dichroic fog made the formula
obsolete. This solvent is the main difference between Microdol and
DK-20 and newer formulas. It should be noted that the 1930's fine
grain developers using paraphenylenediamine relied on the considerable
solvent power of this agent. When used in a low pH solution the PPD
is almost as good a solvent as thiocyanate. These developers had the
same problems, only worse, of great speed loss, dichroic fog, and loss
of resolution.
It should also be noted that although D-23 and D-25 are called
high-sulfite developers the sulfite concentration is the same as for
D-76.
Extensive tests by Kodak, as well as the often quoted ones by Dr.
Henry, show that these developers do _not_ reduce resolution. They
may not, however, produce accutance effects because the sulfite keeps
developer reaction products from restraining or accelerating
development at a local level as happens with Rodinal, for instance.
Richard Knoppow
Jean-David Beyer <jdb...@exit109.com> wrote:
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>
>
>e...@clark.net wrote (in part):
>
>> Also, it would be less toxic than Benzotriazole.
>
>I looked up the MSDS for this from two different manufacturers.
>One said it was moderately irritating if the powder were inhaled.
>The other thought it was quite harmless. I would not really want to
>inhale powdered sodium chloride either. BZT is a much better restrainer
>than sodium chloride. I imagine it is there for other reasons.
>
>--
>Jean-David Beyer
>Shrewsbury, New Jersey
Sodium Chloride is not only a restrainer but helps to control the
rate of diffusion of solutions into the gelatin. In fact, if memory
serves me, it tends to favor surface development rather than depth
development which improves sharpness. D-25 and D-23 have no
restrainer other than the reaction products of development which build
up in them so the restraining effect of the salt in Microdol-X and
other developers is more for some other purpose than preventing fog.
Richard Knoppow
david...@aol.com (Davidlindq) wrote:
Whatever patents may have existed for any of the classic developers
have long since expired. Kodak's packaged versions of published
formulas often contained extra ingredients. Even packaged D-76 would
contain, for instance, anti-calcium sequestering agents, etc. Often,
the patent numbers listed for products of this sort don't tell you
much anyway. They may be for some side issue like a technique of
mixing the chemicals at the factory.
When technology changes fairly slowly its useful to keep processes
and methods trade secrets, which can be held forever and have some
legal protection. Where technology is changing rapidly, patents are
advangtageous, insuring that the holder will have exclusive use for
enough time to make some profit from his/her research, but ultimately
making the technology avaiable to everyone.
Richard Knoppow
ki...@usa.net (Sun Demon) wrote:
>On Sun, 14 Sep 1997 00:01:13 GMT, ki...@usa.net (Sun Demon) wrote:
>
>>I think I've read something about Microdol-x being a similar developer
>>to D23.Who knows the Microdol-x formula?
>
>Thank you for all your answers. My new question is: is there a ready
>made developer closer to D23 than Microdol-x? And:
>anybody uses on a regular basis D23 for Tmax 400 and Konica ir750?
>Do you agree with the very interesting article in
>http://www.heylloyd.com/technicl/D23.html
>???
>
Unless Photographer's Formulary or some other specialty outfit makes
it up its not. This was always a mix it yourself formula. Its very
simple, only Metol and Sulfite (and water or course). I rather think
its performance is so close to D-76 that Kodak didn't see enough of a
market for it.
silver
Michael Gudzinowicz wrote in article
<5vgaks$l...@freenet-news.carleton.ca>...
>Richard Knoppow has pointed out the original formula of the old
>Microdol (not X) was a derivative of Kodak's high sulfite DK-20 which
>also contained the silver solvent sodium thiocyanate. The latter
>compound may have lead to a loss of sharpness.
>
>Comments that Microdol-X is less sharp or gives finer grain due to
>silver solvent effects on grain "edges" are unfounded. To examine
>silver grains requires extremely high magnification - the image seen
>with a grain magnifier is a composite of clumped grains. The "grain" or
>granularity in prints is due to uneven development of the negative, and
>the dark print "grains" are "holes" or areas of less development in the
>negative.
>
>With respect to resolution and acutance, Microdol-X was compared to
>Rodinal, D-76 and other developers by Dr. Richard Henry in "Controls in
>Black-and-White Photography" using reliable procedures including a
>microdensitometer to measure acutance. Microdol-X was as good or better
>than other developers depending upon the film tested. Note that
>acutance is measured by the slope of a printed knife edge, and isn't
>the "border effect" with which some people confuse it. Dilute, active,
>grainy developers may give an _impression_ of sharpness, but actual
>measurements will indicate that actual resolution is lost.
>
>If you're looking for a good fine grain combination, you might try T-Max
>100 (TMX) exposed at EI 25 to 32 and developed at 75F in undiluted
>Microdol-X for Kodak's recommended times. Granularity is comparable to
>Tech Pan, and sharpness is very close. To examine the differences
>include a white plastic bag in the "scene", and print for the bag. At
>high enlargements, the bag will retain a grainless sheen similar to
>large format results, while other developer's granularity will "muddy"
>it to give the appearance of a paper bag.
Now that is a very fine contribution and I personally thank you for it. It
was most interesting.
A couple of points: DK20 used sodium thiocyanate, as you correctly stated.
However it was dropped when the then modern emulsions fogged if developed in
thiocyanate. Hence Microdol. I've not read anything different in any
photographic literature to indicate that things have changed.
The acutance thing got underway with the formulae published by Geoffrey
Crawley "after lengthy research" (Brit J. Photog, Vol 107, 2, 9, 16, 23 ,
30 December 1960 and ibid Vol 108, 6 13, 27 January, 1961)
For fine grain, Crawley found that his formula for full film speed, fine
grain and acutance was FX-3 as follows:-
phenidone 0.25
Hydroquinone 6
Sod Sulphite 75
Borax 2.5
All units grams and in 1 Litre.
You will note from this that both D76 and D23 have 100 g of S. sulphite and
this has 75.
Crawley went on to expound his FX-4 Which used both Metol and phenidone and
100 g of Sulphite claiming it gave higher speed and more compensation..
My own view is that modern films are all pretty good and that one's attempts
to vary the final result by messing around with developers is only marginal
at best, It is highly unlikely that one can beat Kodak Ilford or Agfa at
their own game.
When in doubt, read the instruction book.
JS
Michael Gudzinowicz
Richard Knoppow <dick...@ix.netcom.com> writes:
>Jean-David Beyer <jdb...@exit109.com> wrote:
>>
>>SPECTRUM wrote (in part):
>>
>>> And what is boric anhydride ? Some form of boric acid ? As a buffer ?
>>
>> Boric acid is H3BO3. I would have guessed that Boric anhydride would be
>>HBO2; i.e., boric acid with one water molecule missing, but Eastman Organics
>>it is the same as Boron Oxide, B2O3. I.e., two boric acid
>>molecules with three water molecules missing between them. There is also
>>tetra-boric acid (pyro-boric acid): H2B4O7. I assume that the boric anhydrid
>>is more soluble than the boric acid, but did not look it up.
> I think the Boron anhydride or oxide becomes Boric acid in solution.
>Perhaps it is more stable in its un-mixed condition.
Anhydrides are dimers of acids which form when they are dehydrated
losing water, but they aren't stable in aqeous solutions, and form the
parent acids.
For a simple anhydride, like acetic anhydride:
O O
H3CC-O-CCH3 + H2O -> 2 CH3COOH
For boric anhydride, the reaction requires another hydration:
O=B-O-B=O + H2O -> 2 HB02
2 HB02 + 2 H2O -> 2 H3BO3 (boric acid)
Michael Gudzinowicz
"silver" <jon...@s054.aone.net.au> wrote:
>Now that is a very fine contribution and I personally thank you for it. It
>was most interesting.
>
>A couple of points: DK20 used sodium thiocyanate, as you correctly stated.
>However it was dropped when the then modern emulsions fogged if developed in
>thiocyanate. Hence Microdol. I've not read anything different in any
>photographic literature to indicate that things have changed.
I'm not sure if I was clear on that point, that the original Microdol
used silver solvents, but Microdol-X doesn't.
>The acutance thing got underway with the formulae published by Geoffrey
>Crawley "after lengthy research" (Brit J. Photog, Vol 107, 2, 9, 16, 23 ,
>30 December 1960 and ibid Vol 108, 6 13, 27 January, 1961)
>
>For fine grain, Crawley found that his formula for full film speed, fine
>grain and acutance was FX-3 as follows:-
>
>phenidone 0.25
>Hydroquinone 6
>Sod Sulphite 75
>Borax 2.5
>
>All units grams and in 1 Litre.
>
>You will note from this that both D76 and D23 have 100 g of S. sulphite and
>this has 75.
I think FX-3 also used 1 g/l of KBr.
I liked to use Agfa 17 and its replenisher. The formula and approach
are similar to that above: metol, 1.5; sulfite, 80; HQ, 3; borax, 3;
KBr, 0.5.
>Crawley went on to expound his FX-4 Which used both Metol and phenidone and
>100 g of Sulphite claiming it gave higher speed and more compensation..
If anyone is interested, FX-4: metol, 1.5; sulfite, 100; HQ, 5;
phenidone, 0.5; borax, 2.5; KBr, 0.5. He claimed a 30% increase with
FX-3 and 60% with FX-4.
>My own view is that modern films are all pretty good and that one's attempts
>to vary the final result by messing around with developers is only marginal
>at best, It is highly unlikely that one can beat Kodak Ilford or Agfa at
>their own game.
>
>When in doubt, read the instruction book.
There's a lot of useful info in the EKC tech sheets - if someone has
determined optimal time/temp parameters, they are easily translate to a
CI value, which can be used with new combinations. The same holds true
for N +/- development. Unfortunately it seems that people ignore the
charts.
Michael Gudzinowicz
Richard Knoppow <dick...@ix.netcom.com> writes:
> Sodium Chloride is not only a restrainer but helps to control the
>rate of diffusion of solutions into the gelatin. In fact, if memory
>serves me, it tends to favor surface development rather than depth
>development which improves sharpness. D-25 and D-23 have no
>restrainer other than the reaction products of development which build
>up in them so the restraining effect of the salt in Microdol-X and
>other developers is more for some other purpose than preventing fog.
Iodide favors surface development with older emulsions, but only with
active metol developers containing low levels of metol. An example is
Crawley's FX-1. I've tried to duplicate the effect with the T-grain
high iodide films, but the low level of iodide doesn't deem to have an
effect.
Jean-David Beyer
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Michael Gudzinowicz wrote:
> Anhydrides are dimers of acids which form when they are dehydrated
> losing water, but they aren't stable in aqeous solutions, and form the
> parent acids.
>
> For a simple anhydride, like acetic anhydride:
>
> O O
> H3CC-O-CCH3 + H2O -> 2 CH3COOH
>
> For boric anhydride, the reaction requires another hydration:
>
> O=B-O-B=O + H2O -> 2 HB02
> 2 HB02 + 2 H2O -> 2 H3BO3 (boric acid)
While Michael Gudzinowicz does not post here as much as many others,
I wish to express my appreciation to him publicly here for his consistently
clear and accurate posts that are made in a manner understandable to all.
--
Jean-David Beyer
Shrewsbury, New Jersey
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Clyde Davidson
Tim Daneliuk wrote ...>
>I infer from reading the URL you cite above that you like D-23 because
>of its ability to keep the highlights from blowing out in the negative.
>I cannot comment on how close it is to D-23, having never used this
>developer, however, I process Agfapan APX 100 in PMK Pyro and get
>marvelous results. I have also used PMK Pyro with Tri-X and TMX, again
>with very good results. I have consistently found that PMK Pyro appears
>to hold the highlight detail longer than other developers like HC-110
>or T-Max RS. This is, of course, a subjective call, based on observation
>not rigorous testing. You might want to try this developer and see
>how you like it. If you do, Hutchings' "Book Of Pyro" is a must.
>
I just started using PMK with Delta 400. Great stuff!!! I was hooked after
the first batch. I've got to try it with Delta 100; I've heard that is a
phenomenal match.
I'd say that my non-rigorous testing matches yours. I've never seen the
highlights, high range tones, and clear whites like I've seen with anything
else. Not even close. This stuff opens up creative possibilities. This
doesn't even get into the incredible sharpness.
Clyde Davidson
Rick Schiller
silver
I would like to publicly apologise for not including the bromide in the FX3
formula when I repeated it. I was not trying to be clever, just clumsy.
The relevant parts of the post for do it yourselfers is now below.
I will add that I would expect that the practical differences in every day
shooting between Microdol X and FS-3 or FX-4 would be not easily
discernible.
JS
>>For fine grain, Crawley found that his formula for full film speed, fine
>>grain and acutance was FX-3 as follows:-
>>
>>phenidone 0.25
>>Hydroquinone 6
>>Sod Sulphite 75
>>Borax 2.5
Pot Bromide 1.0
>>All units grams and in 1 Litre.
>>
>If anyone is interested, FX-4: metol, 1.5; sulfite, 100; HQ, 5;