Who makes all the films anyway?

[Murray@uptowngallery]

OK - the plot thickens...

Shot a roll at ISO 100 of several pieces of gray-to-black matboard & measured EV 7-11. Set camera at 9.4-ish (1/25 and f/5.6), then 1/10 and 1/5 and 1/2. First three frames made horrible noises while winding. Repeated same 4 exposures again (6x9 for 8 exp). Later found they were shredded.

Did roll at 7 minutes at buddy lab in Tmax developer (that's what they use).

Advise was 6 minutes and ISO 50 for next roll. No visible fog (not measured on densitometer) in my opinion.

Does 'nailing' the correct film manufacturer allow id'ing it's age better? Acetate more brittle than polyester?

Someone suggested 'flame test' to id acetate.

I'm just curious how old it is now that I see it's useable.

Thanks

Murray

[Ed Sukach]

The *really* old films were on a nitrocellulose base - a.k.a. "cellophane" or "celluloid". The burn test is valid - if it burns with a clear, yellow flame, with little ash and no "smoldering", it is most probably nitrocellulose. I recently processed a roll of film discovered in an antique shop - Ansco "Plenachrome" - and that was "nitro". Kodak advertised its departure from nitro by edge marking its film as "Kodak Safety Film". Nitrocellulose was first developed as a substitute for ivory in the making of billiard balls; it is also the primary ingredient in "smokeless" gun powder. Many Motion Picture Theaters - Cinemas - burned to the ground when the nitro film in the projector ignited from the heat of the projection lamp - thus the concern with "Safety."