dorsey film conversion questions and estimate

[Koontz John E]

On Wed, 11 Feb 2004, Jimm GoodTracks wrote:
> There's lots of data online about the decay of cellulose acetate film,
> though it all mentions that after 1950 NAA filming was done mostly on
> poly-something-or-other. The NAA SIRIS catalogue lists the "Tciwere and
> Winnebago Folk-lore, including Iowa Cults" as being the first item on the
> reel that also contains the slips.

Mark has pointed out to me that there is a quality difference between
"black background silverbase" and "blue background diazo."  The latter has
a shorter shelf-life.  Could that be the issue?