Posts: 139
From: La Mesa, CA, USA
Registered: Nov 2008
posted January 04, 2010 09:08 PM
I have seen lots of Kodak camera film, B&W and Kodachrome, with VS. Most of it is from the mid-1930s and 1940s, but once in a while even films from the 1950s have it. Once again, the stuff stored in the tight cans is most prone, from my experience.
Posts: 139
From: La Mesa, CA, USA
Registered: Nov 2008
posted January 07, 2010 01:00 PM
Whenever I have seen the base of Kodachrome specified it has been triacetate propionate. According to this report, Kodak discontinued diacetate films around 1940.
Posts: 791
From: Northridge, CA USA
Registered: Jun 2003
posted January 07, 2010 01:29 PM
I don't think Kodachrome was on diacetate, what I found was:
"Kodachrome Film is currently made on cellulose acetate propionate support."
I haven't been able for find any reference where this was changed and why that emulsion was made on that base may relate to the coatings or the coupler/color developers in processing. In any event, it would show as a difference in edge transmission. As I recall 7387 had a different edge look that 7381 (Eastman Reversal Color Print/Eastman Color) which was also different from Ektachrome Print and Ektachrome R Print (7386/7388).
The base material for 7386,7388 and 7381 were all identical so it must have been an observation based on some other factor. 7386 and 7388 didn't have the rem-jet backing but a silver colloidal (sp) anti-halation layer. 7381 and 7387 however did have a rem-jet backing (a carbon black back of film coating that was removed in the first stage of development).
There was a black light test for nitrate/safety film but that was because a chemical had been added to all the safety film materials to make that test possible.