[pure-silver] Re: PIQUED MY CURIOSITY; was Phenidone in alcohol
- From: "Richard Knoppow" <dickburk@xxxxxxxxxxxxx>
- To: "Pure-Silver Free" <pure-silver@xxxxxxxxxxxxx>
- Date: Thu, 7 May 2009 10:50:31 -0700
----- Original Message -----
From: "BOB KISS" <bobkiss@xxxxxxxxxxxxx>
To: <pure-silver@xxxxxxxxxxxxx>
Sent: Thursday, May 07, 2009 8:33 AM
Subject: [pure-silver] Re: PIQUED MY CURIOSITY; was
Phenidone in alcohol
DEAR BILL,
Thanks so much for the info below and looking forward to any
film/time combinations you are willing to share. I use
T-max 100, T-max
400, Tri-X Delta 100 & 400, and HP-5 and Rollei Retro films.
Any suggestions you can make would be great!
CHEERS!
BOB
FWIW, DK-60a was a very active film developer intended
for photofinishing and press work. I don't know the
difference between the original version and the "a" version.
Kodak DK-60a For Photofinishing and Professional Photography
Water (at 125F or 52C) 750.0 ml
Metol 2.5 grams
Sodium sulfite, dessicated 50.0 grams
Hydroquinone 2.5 grams
Kodalk 20.0 grams
Potassium bromide 0.5 grams
Cold water to make 1.0 liter
Dissolve chemicals in order given.
Average development time in a deep tank about 7 minutes at
68F
Compare this with DK-50 which was in production until fairly
recently.
Kodak DK-50 For Professional Films and Plates
Water (at 125F or 52C) 500.0 ml
Metol 2.5 grams
Sodium sulfite, dessicated 30.0 grams
Hydroquinone 2.5 grams
Kodalk 10.0 grams
Potassium bromide 0.5 grams
Cold water to make 1.0 liter
Dissolve chemicals in order given.
For tank development of portrait negatives dilute with an
equal volume of water;
develop about 8 minutes @ 68F.
For tray development use without dilution; develop about 4
minutes at 68F.
For commercial use use without dilution; develop about 8
minutes in a tank or 6 minutes in a tray at 68F.
Note: these are times for c.1947 films. The difference
between "portrait" and "commercial" negatives is contrast.
At the time "commercial" negatives were developed to perhaps
a paper grade or more greater contrast. These days most
films would be developed as "portrait" negatives.
In general the films of this and earlier periods
required longer development times than modern films for
similar contrast. Because of this some of the older
developers develop too quickly for use with modern films.
DK-50 has half the amount of Kodalk (sodium metaborate) of
DK-60 and Kodak developing charts of the recent past that
listed it required it to be diluted 1:1. There is a
difference in diluting developer and modifying its contents.
In the case of these two diluting them to get similar
activity leaves the DK-60 with less developing agents and
probably less capacity. Also, there may be an effect on
grain due to the relatively smaller concentration of salts
in the diluted DK-60, i.e., the diluted DK-60 will probably
be grainier. The low sulfite is probaby also the cause of
the increased edge effects vis: acutance.
I suspect the amount of alkali could be reduced even
further. By reducing the metaborate to around 2 grams and
increasing the sulfite to around 75 grams you have something
along the lines of Kodak's motion picture negative
developer.
OTOH, Bill evidently has a lifetime supply of the stuff
and it does work in diluted form.
--
Richard Knoppow
Los Angeles, CA, USA
dickburk@xxxxxxxxxxxxx
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