FX-39 too strong

I find times with Paterson FX-39 too short for Pan-F, Neopan 1600, and
Delta 100. I wanted to see whether I could add a bit of boric acid to
slow down the developing action without diluting so much. For instance,
Delta 100 in FX-39 diluted 1+19 is too contrasty even at 7.5 minutes. I
like to get to at least 8 minutes (preferably 10-12) to get the most
uniform results. It seemed imprudent to go beyond the 1+19 dilution to
get a longer time. So today I ran some Delta 100, but instead of
diluting beyond 1+19 or developing for less than 7 minutes, I added 1
gram of boric acid to the solution, which was 40ml of FX-39 in 600ml of
water (1+14). Not knowing exactly what the effect would be, I tried 8
minutes for the first film. It was under-developed. I went outside and
quickly shot another roll to have something to run. I gave the second
roll 12 minutes and it looks very close to what I want. I may cut it
back a little to 0.5 gram of boric acid for every 40 or 50ml of stock
and see how that looks.
I got the boric acide from Photographer's Formulary.

The problem with heavily modifying a formula is that it isn't that
formula anymore.
I don't know what is in FX-39 so its difficult to predicet the
effect of Boric acid. I've never seen it used in another formula.
In general lowering the pH of a developer will reduce its activity
but it may also affect other properties. In the case of D-76, in its
buffered form, or other buffered developers like Microphen, the
buffering is adjusted to about the same activity as an unbuffered
formula. In some older developers, like Kodak D-61a, an acid is added
to adjust pH as well as to add some buffering.
If your developing times are very short I suggest using another
developer of less activity. Delta 100 in D-76 1:1 or in Xtol 1:1 should
give you times long enough to shorten them for contrast adjustment. As
a rule of thumb standard emulsion films cnange about one paper grade
with about 33% change in development time but core shell films like
Delta or T-Max need only about 20% to 25% time changehe same contrast
change. I think, in fact, this is why many photographers have problems
with these films.
There are even less active developers. For instance D-25 requires
substantially longer time than most other developers. It is an
extra-fine-grain developer with very little edge/border effects so does
not produce "acutance" effects but diluted 1:3 it becomes an acutance
developer with quite long development times. At 1:3 it looses its
extra-fine-grain property and is about the same as D-76 but produces
full film speed.
Richard Knoppow
Los Angeles, CA, USA

The problem is simply that FX-39 is very good as it is, but dilutions
of beyond 1+17 are required to get the times long enough for my
satisfaction (at least 8 minutes, preferably 10-12).

Having tried numerous other developers, I can with assurance say that
FX-39 is one of the best. It certainly is the sharpest! Acutol offers a
bit more shadow detail and a little less highlight density, but I can
use Acutol in the range of dilutions from 1+14 to 1+17, at which it
seems to be optimum.

Why FX-39 is more active than Acutol is beyond me, but it is. The
Health & Safety (COSSH) Data Sheets show a higher ph for FX-39 (ph
10-10.5) than for Acutol (ph 9.0-10.0), so I'm not crazy for thinking
that the activity of FX-39 is higher.

http://www.patersonphotographic.com/.../Cossh-Tol.pdf

http://www.patersonphotographic.com/...Cossh-FX39.pdf

The question for me is how to get FX-39's ph down to give 10-minute
developing times on the fast-developing films such as Pan-F, Neopan
1600, and Delta 100, while affecting the other properties as little as
possible.

Adding a mild acid such as sodium bisulphite or boric acid is the usual
route to adjusting the ph in a photographic developer. I have both
acids in my chemical stocks.

I must admit the negatives look fine, so I shall continue to experiment
to titrate the amount of acid to be used. I'm going to prepare a 1%
solution of boric acid (10g in 1000ml water) and work with a 1:1 ratio
of that solution to the FX-39 in the next round of trials. That's about
half the ratio of boric acid I used this past weekend.

wrote in message
oups.com...
The problem is simply that FX-39 is very good as it is,
but dilutions
of beyond 1+17 are required to get the times long enough
for my
satisfaction (at least 8 minutes, preferably 10-12).

Having tried numerous other developers, I can with
assurance say that
FX-39 is one of the best. It certainly is the sharpest!
Acutol offers a
bit more shadow detail and a little less highlight
density, but I can
use Acutol in the range of dilutions from 1+14 to 1+17, at
which it
seems to be optimum.

Why FX-39 is more active than Acutol is beyond me, but it
is. The
Health & Safety (COSSH) Data Sheets show a higher ph for
FX-39 (ph
10-10.5) than for Acutol (ph 9.0-10.0), so I'm not crazy
for thinking
that the activity of FX-39 is higher.

http://www.patersonphotographic.com/.../Cossh-Tol.pdf

http://www.patersonphotographic.com/...Cossh-FX39.pdf

The question for me is how to get FX-39's ph down to give
10-minute
developing times on the fast-developing films such as
Pan-F, Neopan
1600, and Delta 100, while affecting the other properties
as little as
possible.

Adding a mild acid such as sodium bisulphite or boric acid
is the usual
route to adjusting the ph in a photographic developer. I
have both
acids in my chemical stocks.

I must admit the negatives look fine, so I shall continue
to experiment
to titrate the amount of acid to be used. I'm going to
prepare a 1%
solution of boric acid (10g in 1000ml water) and work with
a 1:1 ratio
of that solution to the FX-39 in the next round of trials.
That's about
half the ratio of boric acid I used this past weekend.


The problem is that neither MSDS gives even a hint about
the actual ingredients. Without knowing at least what
reducing agents are being used its pretty difficult to guess
at what a modification will do. I really don't like using
"secret" formulas.


--
---
Richard Knoppow
Los Angeles, CA, USA

The problem is that neither MSDS gives even a hint about
the actual ingredients. Without knowing at least what
reducing agents are being used its pretty difficult to guess
at what a modification will do. I really don't like using
"secret" formulas.



Me neither!

Mark

It has hydroquinone, that's for sure; says so on the bottle.
What I wanted to say is that this boric acid seems to work quite well.