[pure-silver] Re: Old Paper Results
- From: DarkroomMagic <info@xxxxxxxxxxxxxxxx>
- To: PureSilverNew <pure-silver@xxxxxxxxxxxxx>
- Date: Thu, 06 Oct 2005 17:17:17 +0200
Richard
Please explain. This note isn't as fact-filled as your typical notes. These
test results sound rather vague. 'probably as good as new' and 'somewhat
soft looking', or even 'has full contrast' don't sound like a test results
but mere observations without measurable evidence.
I did conduct a test to determine the effect of paper age on contrast a few
years ago. These were made on a variety of papers, I had for up to ten years
and they were stored at 5 degC. Their contrast was measured every two years.
The study wasn't very scientific either, but it produced numerical values,
which were compared and found to be consistent. The result was as follows:
1. All papers get softer with age.
2. Some papers are more stable than others
3. The effect is significant an averages about 1/2 grade over 3 years.
4. The effect can be compensated with filtration as long as max contrast is
not required.
I think it is fair to assume that paper stored at room temperature would see
a higher loss of contrast in the same amount of time.
Regards
Ralph W. Lambrecht
http://www.darkroomagic.com
On 2005-10-04 06:15, "Richard Knoppow" <dickburk@xxxxxxxxxxxxx> wrote:
> As a result of a question posted to rec.photo.darkroom I
> decided to dig out and test some very old paper I have. The
> samples were of Kodak Medalist and Agfa Brovira. None of the
> packages has an expiration date but I've had them for at
> least ten years and probably bought them as out dated paper
> then. All packates were opened years ago and have had no
> special storage.
> To make a long story short both boxes of Medalist and the
> Brovira work fine and probably look as good as they did new.
> Its possible the Medalist has lost some contrast but my
> memory of it is that it was a somewhat soft looking paper
> originally. The Brovira has full contrast. I have even more
> Agfa paper in storage and will have to get it out. About the
> only old Agfa paper I had trouble with came from a flooded
> basement and was blotchy, obviously moisture had gotten in.
> Otherwise the stuff seems to last forever.
> I have not had such good luck with old Kodak paper and
> stopped buying outdated paper about the time I got the
> Medalist. Mostly the bad paper was Polycontrast which had
> very low contrast for all filters, evidently, the high
> contrast emulsion component had lost substantial
> sensitivity. It made good drawing paper.
> I also found I have two unopened boxes of Oriental
> Seagull paper, also at least ten years old but bought new at
> the time. I have not tested this yet and will report when I
> do.
>
> Processing of the above was conventional. I used Agfa Neutol
> Plus, an ascorbic acid (and probably Phenidone) developer
> without any added anti-fog.
> I also used this occasion to test the Kodak Enlarging
> Ektar I picked up a couple of weeks ago. This is a 75mm
> lens. Its very sharp, as good as my Schneider Componon, not
> bad for $10 :-)
>
> ---
> Richard Knoppow
> Los Angeles, CA, USA
> dickburk@xxxxxxxxxxxxx
>
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