From: Richard Knoppow on

"Nicholas O. Lindan" <see(a)sig.com> wrote in message
news:W42dnYEoz7vuKsXRnZ2dnUVZ_sudnZ2d(a)earthlink.com...
> "Richard Knoppow" <dickburk(a)ix.netcom.com> wrote
>
>> The line about T-Max being as fine grained in Microdol-X
>> as Technical Pan in Technidol is from me.
>
> HA! If I could get Google to search rec.photo.darkroom -
> I am sure I was pointing this out as early as ...
>
> * * * *
>
> Perceptol - from the MSDS information - doesn't really
> look a whole lot like Microdol-X
>
> Part A:
> Metol
>
> Part B
> S. Sulfite
> S. Bromide
> S. Tripolyphosphate (STPP)
>
> The STPP is a water softening agent in this application
> (among it's other uses it adds weight to seafood by making
> it retain water). I don't know if there is a dichroic
> fog inhibitor or if the bromide takes care of it.
>
> I guess P. Bromide could be a fine-grain agent, but I
> would
> wonder about its effect on shadow detail. The only film
> developer w/ bromide TIKO (WTEO Perceptol) is D-96, used
> by the motion picture industry.
>
> One rather whacked-out developer in the Microdol-X vein
> is Rollei RLS (LP Cube XS) that is made from
>
> Metol
> Ammonium Chloride
>
> without the s. sulfite (if the MSDS can be believed).
>
> --
> Nicholas O. Lindan, Cleveland, Ohio
> Darkroom Automation: F-Stop Timers, Enlarging Meters
> http://www.darkroomautomation.com/da-main.htm
> n o lindan at ix dot netcom dot com
Be careful! The MSDS you have for Perceptol is an old
one and in error. I wrote them about the sodium bromide, its
suppsed to be sodium chloride. Its possible that Microdol-X
has ammonium chloride in it, I think the cation may not be
important. But there are often several versions of MSDS
around. Also, they don't show all the ingredients, only
those deemed to be hazardous and sometimes not even those if
present in very small quantity. For instance both T-Max and
T-Max RS are Phenidone developers but no mention of it was
made in their MSDS for years.
Many packaged developers have some sort of sequestering
agent or agents in them to control impurities in the water,
mostly magnesium and calcium carbonates, the most common
"hardness" in water and sometimes also trace metals like
iron.
I don't have an actual formula for Microdol/Perceptol
but it appears to contain about 15 or 20 grams of sodium
chloride per liter of working solution, otherwise similar to
D-20. I am pretty sure the X in Microdol-X is a silver
sequestering agent, perhaps a mercaptan, to prevent dichroic
fog. I never had any problem with this from Perceptol so
perhaps it too has some anti-silvering agent in it.
Kodak has a ton of patents for anti-silvering agents,
who knows which were actually used and where since they can
also be added to emulsions.



--
Richard Knoppow
Los Angeles, CA, USA
dickburk(a)ix.netcom.com



From: Nicholas O. Lindan on
"Richard Knoppow" <dickburk(a)ix.netcom.com> wrote

> The MSDS you have for Perceptol is an old one and in error. I wrote them
> about the sodium bromide, its suppsed to be sodium chloride.

Ah, now that makes a lot more sense.

When Kodak announced the discontinuation of Microdol-X
I looked into Perceptol, came upon the erroneous MSDS
and promptly bought 10 bags of M-X.

I have tried the home-brew Microdol - D-23 with a 30 (?)
gm/l dollop of pure NaCl and it silvers badly when used
with TMax films.

If Perceptol works with TMax/Delta then it more than likely
has an anti-silvering agent in it.

Hmm, anti-silvering -> anti-Ag'ing -> Anti-Aging. I wonder
if one could sell the stuff on the back pages of the National
Enquirer. Proven Anti-Aging formula ... Might help all those
people poisoning themselves with colloidal silver.

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


From: IanG on

Perceptol contains Sodium Chloride and no Bromide, that's an error in an
old MSDS and has already been pointed out in this thread.

Ian

Nicholas O. Lindan;885966 Wrote:
> "Richard Knoppow" dickburk(a)ix.netcom.com wrote
> -
> The line about T-Max being as fine grained in Microdol-X as Technical
> Pan
> in Technidol is from me.-
>
> HA! If I could get Google to search rec.photo.darkroom -
> I am sure I was pointing this out as early as ...
>
> * * * *
>
> Perceptol - from the MSDS information - doesn't really
> look a whole lot like Microdol-X
>
> Part A:
> Metol
>
> Part B
> S. Sulfite
> S. Bromide
> S. Tripolyphosphate (STPP)
>
> The STPP is a water softening agent in this application
> (among it's other uses it adds weight to seafood by making
> it retain water). I don't know if there is a dichroic
> fog inhibitor or if the bromide takes care of it.
>
> I guess P. Bromide could be a fine-grain agent, but I would
> wonder about its effect on shadow detail. The only film
> developer w/ bromide TIKO (WTEO Perceptol) is D-96, used
> by the motion picture industry.
>
> One rather whacked-out developer in the Microdol-X vein
> is Rollei RLS (LP Cube XS) that is made from
>
> Metol
> Ammonium Chloride
>
> without the s. sulfite (if the MSDS can be believed).
>
> --
> Nicholas O. Lindan, Cleveland, Ohio
> Darkroom Automation: F-Stop Timers, Enlarging Meters
> http://www.darkroomautomation.com/da-main.htm
> n o lindan at ix dot netcom dot com




--
IanG
From: Richard Knoppow on

"Keith Tapscott." <Keith.Tapscott..69f9028(a)photobanter.com>
wrote in message
news:Keith.Tapscott..69f9028(a)photobanter.com...
>
> The only difference I can see from the MSDS for Microdol-X
> and
> Perceptol, is that Kodak list boric oxide (B2O3) as a
> component. Both
> developers list sodium chloride as constituents.
>
> A former Kodak pundit has mentioned on a popular
> photo-forum, that Kodak
> encapsulate the developing agents with a special coating
> to prevent them
> from reacting with the other constituents in the
> single-powder
> compounds.
>
> I am wondering if that special component is the boric
> oxide (boric
> anhydride) that Kodak mention in their MSDS's.
>
> Ilford do similar to their P.Q. powder developers by
> adding a pinch of
> sodium metabisuphite in Part 'A' of Microphen and
> Bromophen, but not in
> ID-11 or Perceptol, as Metol is already slightly acidic.
>
> Ilford information sheet P 10.5 FINE GRAIN DEVELOPMENT:
> Shows that ID-11
> and ID-2 can be modified to produce finer grain by adding
> ammonium-chloride. Use 40 grams for each litre of stock
> ID-11 and 10
> grams for each litre of working strength ID-2 (1+2).
>
>
>
>
> --
> Keith Tapscott.
Kodak uses some odd chemical names for more familiar
stuff in their MSDS. Kodak also has a bunch of patents on
methods of combining chemicals for use in powder formulas, I
have no idea of which ones were actually used commercially.
AFAIK, boric anhydride is becomes boric acid in solution and
suggests that there is a buffer combination there similar to
the one in D-76d which uses borax and boric acid.
Those familiar with the art (patent speak) know that
its usual in published formulas to list the chemicals in the
order in which they are to be dissolved. When a developer
contains Metol it is dissolved first, or at least before the
sulfite. The reason is that Metol does not dissolve in a
fairly strong sulfite solution. In the past it was common
for packaged developers to come in two parts, the first
contained the Metol and was dissolved first, the second
contained the remainder of the ingredients. Kodak has a
method of treating the chemicals in packaged developers so
that all can be combined at once. Note that packaged D-76
and Dektol consist of a single container. I don't know
exactly what they do. One reads occasional complaints about
the difficulty of dissolving these packaged developers
without having a residue of undissolved crystals. I have
wondered if this problem is the result of this treatment.
BTW, I've found that the problem is at least minimised by
keeping the solution hot until solution is complete.
Kodak is reportedly discontinuing D-76, Microdol-X, and
Kodak Hypo Clearing Agent. Ilford makes similar if not
identical products but Kodak originated all of these and I
can't help but wonder if the Ilford versions are really
identical. For one thing the MSDS for ID-11 indicates its
not buffered. D-76 has a problem with increasing activity as
it ages which is cured by the buffering found in the Kodak
version. Perceptol seems to work very well and I routinely
use it for T-Max 100 and have used it for several other
films. I am not sure what is in Ilford wash aid but its
seems to be the same as KHCA, a buffered solution of sodium
sulfite. Kodak adds two sequestering agents to control
deposition of aluminum compounds from the hardener and
metallic carbonates in the water. I wonder if Ilford adds
these since they do not use hardener in their fixing baths.
Unfortunately we live in a age of super-giant
corporations, that way because it is "more efficient" but,
in fact they are not very efficient and are incapable of
catering to medium or small markets profitably, something
that smaller and more specialized businesses _are_ able to
do. Being big is not always an advantage. Years ago I came
across a very interesting paper called "On Being the Right
Size". I can't remember the author, it was in an anthology
of papers on either mathematics or physics published by
_Scientific American_ magazine. Maybe a web search would
find it.


--
--
Richard Knoppow
Los Angeles, CA, USA
dickburk(a)ix.netcom.com


From: Jean-David Beyer on
Richard Knoppow wrote:

> Being big is not always an advantage. Years ago I came across a very
> interesting paper called "On Being the Right Size". I can't remember
> the author, it was in an anthology of papers on either mathematics or
> physics published by _Scientific American_ magazine. Maybe a web
> search would find it.
>
It can be found in The World of Mathematics, Volume 2, pages 952 ff.
"On Being the Right Size" by J.B.S. Haldane. Haldane, J. B. S. (March
1926). "On Being the Right Size". Harper's Magazine.


--
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