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Topic: The truth about Vinegar Sydrome!
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John Whittle
Jedi Master Film Handler
Posts: 791
From: Northridge, CA USA
Registered: Jun 2003
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posted November 13, 2009 10:03 AM
This is from a fifty cent Kodak book "Storage and Preservation of Motion Picture Film" This is the early blue cover edition, I have a later one somewhere but the following will be of interest to some:
"The base of support of acetate motion picture film, which is approximately .0055 inch in thickness is usually made from cotton or wood cellulose by chemical treatment which coverts it into a plstic. In former years, most motion picture film support was of the highly flammable, cellulose nitrate type. The only "safety" or slow-buring films up to about 1938 were made from acetone=soluble cellulose acetate. These were followed by the cellulose acetate propionate and acetate butyrate types. In spite of the hazardous nature of nitrate film and the safety precautions which were necessary in the handling and storage of this materi, it was preferred over the early types of acetate film for commercial 35mm use because of its superior physical characteristics. In recent years, an improved safety support made of high acetyl cellulose acetate (commonly called "cellulose triacetate") has been developed and this new safety support is fully suited to the rigid requirements of commercial motion picture use. As a result, the Eastman Kodak Company has not manufactured any nitrate film in the United States since 1951. Although virtually all Eastman 35mm motion picture filmas as well as 16mm black and white motion picture films are now made on triacetate support, Kodachrome Film is currently made on cellulose acetate propionate support. Kodachrome andEastman Color Films were never made on nitrate base, but imbibition color print and various two-color print stocks were made on nitrate film for a number of years prior to 1951.
The current Kodachrome spec sheet makes no metion of film support. http://www.kodak.com/global/en/professional/support/techPubs/e55/e55.pdf
The current Care and Storage publication is now 12 pages and is here: http://www.kodak.com/global/en/consumer/products/techInfo/e30/e30.pdf
There is a Kodak Publication, which I could not find on line: "The Book of Film Care" publication H-23.
The publication quoted has no copyright date, but the back page has a code 3-57 and I would guess that's the revision date of the book.
John
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Bill Brandenstein
Phenomenal Film Handler
Posts: 1632
From: California
Registered: Aug 2007
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posted January 04, 2010 02:48 PM
A new thought about home movies, VS, and which support the films might be made on. (For the previous post with amazing technical data, see John Whittle's 11/13/2009 10AM post.)
First, a little technical review based on John's post above. The first safety films were not just one chemical approach (cellulose diacetate) but three: acetone-soluble cellulose acetate, cellulose acetate propionate, and acetate butyrate. Then at some point most of it shifted to "high-acetyl cellulose acetate" which we normally refer to as cellulose triacetate.
Any of our studio or Blackhawk prints would be on this base, and when you view light through the side of the reel, have a medium amber color. Some films are lighter or darker than others, but triacetate prints never seem to be opaque, nor as light as mylar/polyester/estar prints, which are quite a bit more transparent through the film base.
Here's the new point. All the Super 8 Kodak stock that I have, from my first roll in the 70s, right up to current Plus-X and 64T rolls (sorry, have never shot negative) and recent Kodachrome, are opaque. Even with a bright light, almost no light gets through its side. Lest you think this happens because of different emulsion properties, this is still true even when the emulsion is removed with bleach. With no emulsion, it still is nearly opaque.
So at this point I would propose the radical opinion that ALL Kodak 8mm camera film is on diacetate TO THIS DAY. based on the fact that it looks like no other film through the side. Is diacetate less prone to VS than triacetate? I can't tell, but 100-year-old Edison films have turned up on eBay in projectable condition. However, I've seen old Kodachrome with VS.
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