Archived posting to the Leica Users Group, 2013/05/22

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Subject: [Leica] [OM] IMG: Film ID?
From: piers.hemy at gmail.com (Piers Hemy)
Date: Wed, 22 May 2013 16:59:33 +0100

Tina

It is almost certainly a Ferrania-made reversal film marketed by its parent,
Minnesota Mining & Mfg, otherwise known as 3M. Most likely it was branded 3M
ColorSlide, and dates to before 1986. I like the graininess! I like the
image anyway, but still.

The following extract from the footnotes to the Wihelm Institute report on
longevity of transparencies has some detail - the full report is at : 
http://www.wilhelm-research.com/pdf/HW_Book_06_of_20_HiRes_v1b.pdf
===================
Only 3M ScotchChrome 100 film was included in these tests; however, 3M
ScotchChrome 400 and 800/3200 films probably have similar projector-fading
stability. 3M ScotchChrome films formerly were called 3M Scotch Color Slide
films; prior to that they were sold under the 3M ColorSlide name. In 1986
the name was changed to Scotch and the film packaging redesigned in an
attempt to build stronger identification with the well-known 3M "Scotch"
brand (e.g., Scotch tapes). The data given here are for the "improved type"
films introduced in 1988.
(At the time this book went to press in 1992, ScotchChrome 640T and 1000
films were still being sold. These films have projector-fading
characteristics that are generally similar to the improved 1988 films;
however, the 640T and 1000 films have inferior dark fading stability
compared with the new films.) Polaroid Presentation Chrome film is a
non-instant E-6 film made for Polaroid by 3M; Presentation Chrome is
apparently identical to ScotchChrome 100 Film. Although labeled "Made in
USA," 3M ScotchChrome and 3M Scotch Color Print films in reality are made in
Ferrania, Italy by 3M Italia S.p.A. The films are only packaged in the U.S.
3M Italia is a subsidiary of the 3M Company, St. Paul, Minnesota. In spite
of the relatively good projector-fading stability of 3M ScotchChrome films,
they have comparatively poor dark fading stability and are not recommended.
By the end of the 6-hour intermittent projection tests with 3M ScotchChrome
640T film, a "greasy" surface residue was observed on parts of the emulsion
surface. The nature of this undesirable substance has not been identified,
but it likely is coupler solvent or other emulsion addenda. The residue was
not apparent on slides projected continuously for 6 hours. The exudation
seems to be caused by the combined effects of intermittent projector light
and projector heat. 
====================

I have happy (?) memories of processing 3M Ferrania CR50 reversal film many
years ago, and can recommend finding any alternative to manhandling a
36-exposure length of wet film against a fluorescent tube for the
re-exposure, followed by reloading the same wet film in the spiral for
second develop, bleach fix etc. Yuk.

Piers

-----Original Message-----
From: Tina Manley [mailto:images at comporium.net] 
Sent: 22 May 2013 14:25
To: MUGers at yahoogroups.com; Leica Users Group; paw; seephoto; Olympus 
Camera
Discussion
Subject: [OM] IMG: Film ID?

PESO:

Scanning Guatemalan children.  This is a high-speed, grainy film that has
faded.  The edge of the film says 3M CS 1000.  Google is no help.  Any idea
what film it is?

http://www.pbase.com/image/150330845

Thanks,

Tina

--
Tina Manley, ASMP
www.tinamanley.com
--
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