From: Richard Knoppow on 22 Jul 2008 11:14
"Lew" <lew1716(a)optonline.net> wrote in message
>I always mix my own developers. On the Rolli site there's
>mention of the combo of one of their films at half its
>usual iso developed in ultrafin plus. Thought I'd try it
> "Richard Knoppow" <dickburk(a)ix.netcom.com> wrote in
>> "Lew" <lew1716(a)optonline.net> wrote in message
>>> Is there a published formula for an equivalent to
>>> Tetenal Ultrafin Plus?
The blurb for it on the Tetenal site suggests it does
not lose speed. There are several extra-fine-grain
developers which do lose about a stop of speed. Microdol-X
and Ilford Perceptol are examples. These two are probably
identical. They deliver very fine grain but have no acutance
effect when used full strength. You might be interested in
trying one. I have come to use one or the other routinely
for 100T-Max. In full strength Perceptol it has nearly as
fine grain as the late, lamented Kodak Technical Pan but
about four times the speed and no problems with contrast
control. In larger formats there is not very much difference
but the combination makes 35 mm negatives which begin to
have the smoothness of larger formats. I have not tried it
with other slow T-grain films like Ilford Delta or Fuji
Acros but it should give similar results with them.
The formula for Microdol-X is proprietary but the fine
grain agent in both it and Perceptol is common salt, sodium
chloride. I've seen a couple of variations on what is
represented as the formula. Its similar to D-23 but with the
addition of about 25 grams of sodium chloride per liter.
Note that the salt should be pure, most table salt has
sodium iodide in it as a nutricional supplement and most
have some sort of anti-caking agent. Supposedly kosher salt
is pure sodium chloride. Microdol-X, and probably Perceptol,
have some sort of silver sequestering agent in them to
prevent dichroic fog, a deposition of very finely devided
silver which is a characteristic of very fine grain
developers. I have no idea of what is actually used although
there are some interesting patents issued Kodak about this.
Plain Ultrafin, without the plus, appears from the MSDS
to be very similar to the old "fine grain"
metol-hydroquinone formulas of the 1930s and 1940s except
that it uses potassium salts rather than sodium. This may be
due to the generally higher amount of these salts which can
be dissolved in concentrated developers. Potassium salts may
have slightly different photographic activity than sodium
salts but the difference is not very large.
Frankly, I prefer to use products I know something
about even if I don't mix them myself.
I think the quote Jean-David Beyer was thinking of was
Mees's remark during a lecture that the very large number of
developing agents just shows how many ways there are of
accomplishing exactly the same thing. Mees was the founder
and director of the Kodak Research Laboratories from its
inception in 1912 until his retirement in 1961.
I found a web site on German developers, its in German
which I don't speak but does not appear to have very much
secret stuff on it.
Los Angeles, CA, USA
From: Lloyd Erlick Lloyd at on 22 Jul 2008 17:44
July 22, 2008, from Lloyd Erlick,
Potassium salts do show different
photographic activity from sodium
counterparts, but for film development I
doubt it would be visible or significant in
practical darkroom work.
I have compared simple black and white
*paper* developers made with potassium vs
sodium salts (e.g. the old Ansco 120 formula
- the D23 of paper ...). On warm tone paper
the results from a potassium developer are
slightly but quite visibly warmer. The effect
is not really visible until the paper is
Lloyd Erlick Portraits, Toronto.
On Tue, 22 Jul 2008 08:14:35 -0700, "Richard
Knoppow" <dickburk(a)ix.netcom.com> wrote:
>Potassium salts may
>have slightly different photographic activity than sodium
>salts but the difference is not very large.
> Frankly, I prefer to use products I know something
>about even if I don't mix them myself.
> I think the quote Jean-David Beyer was thinking of was
>Mees's remark during a lecture that the very large number of
>developing agents just shows how many ways there are of
>accomplishing exactly the same thing.
From: Nicholas O. Lindan on 22 Jul 2008 19:26
"Richard Knoppow" <dickburk(a)ix.netcom.com>
> Supposedly kosher salt is pure sodium chloride.
For photography Kosher salt is traif: the anti-caking agent
is P. Ferricyanide. I have no idea if there is enough to
cause any effect, but tiny amounts of P. Ferricyanide are
used for latent image bleaching. Apparently it isn't
the salt that is Kosher but that the salt is used for curing
Morton "Pickling and Canning Salt" is pure salt. Comes
in a green and white box.
Nicholas O. Lindan, Cleveland, Ohio
Darkroom Automation: F-Stop Timers, Enlarging Meters
n o lindan at ix dot netcom dot com