[pure-silver] Re: [pure-silver]Old & new KRST. Was Selenium followed by T-8 Polysulfide
- From: "Tim Rudman" <ps@xxxxxxxxxxxxxxx>
- To: <pure-silver@xxxxxxxxxxxxx>
- Date: Sat, 18 Dec 2004 20:52:59 -0000
-----Original Message-----
From: pure-silver-bounce@xxxxxxxxxxxxx
[mailto:pure-silver-bounce@xxxxxxxxxxxxx] On Behalf Of Ryuji Suzuki
Sent: 18 December 2004 20:38
To: pure-silver@xxxxxxxxxxxxx
Subject: [pure-silver] Re: [pure-silver]Old & new KRST. Was Selenium
followed by T-8 Polysulfide
From: "Tim Rudman" <ps@xxxxxxxxxxxxxxx>
Subject: [pure-silver] [pure-silver]Old & new KRST. Was Selenium followed by
T-8 Polysulfide
Date: Sat, 18 Dec 2004 20:08:07 -0000
> Whilst it could be true, according to Doug Nishimura IPI were not
> able to demonstrate this as an explanation to account for their
> observations (there could be other explanations).
I agree, out of all existing reports that indicate some changes in KRST
during 1990s that I know of, none demonstrates what was changed.
But there are plenty of convincing data that KRST is less effective than KBT
or other sulfiding treatments. This is the source of frustration because
KRST is easy to use, makes nice rich black hue and deepens blacks, while
sulfiding provides stronger protection more consistently across the board.
> [...] He went on to say 'that since we haven't found any solid
> evidence that there was indeed active sulfur in the old bottles of
> selenium toner our suggestion that sulfur might be involved is purely
> speculation.' This does not of course rule it out, - nor in.
Right, another hypothetical difference may be in the film/paper emulsion
part. Susceptibility to oxidative attacks varies with factors like
antifogging agent, not to mention halide composition, size and morphology of
the developed grains, etc. Another hypothetical difference may be that
storage condition, oxidative pollutants, and all other storage-related
conditions changed from 1970's to 1990's.
But there are a few anecdotal reports that are inconsistent with this
hypothesis. While there are a few viable hypotheses remaining, I don't think
determining what happened to a proprietary product in the past is the most
important part.
Please note that I'm not trying to identify the change in KRST or
criticizing Kodak for doing something in this area. I'm merely trying to
incorporate recent findings in a meaningful way to my darkroom practice and
sharing it with others. Somewhere along the way I noted that mixing of KRST
and KBT that worked with old KRST does not work with new bottle of KRST. I
mixed new KRST with liver of sulfur from non-Kodak source, but it resulted
in the same problem. This is not a systematic test and my experience remains
merely anecdotal, but it is consistent with the hypothesis that some change
was made in KRST. It by no means prove it nor did I state it that way.
--
Ryuji Suzuki
No Ryuji, I wasn't suggesting that you did. Your previous email did not
appear until I sent mine off - they crossed in the ether ;-)
Tim
=============================================================================================================
To unsubscribe from this list, go to www.freelists.org and logon to your
account (the same e-mail address and password you set-up when you subscribed,)
and unsubscribe from there.
Other related posts:
