Nitrate & acetate deterioration
One reason for freezing b&w film might be to prevent or slow decomposition as happens with the old nitrate base. It seems there a similar, albeit much longer term deterioration with acetate base material, with the same 'vinegar syndrome', shrinkage and embrittlement. The Image Permanence Institute quotes only 50 years! See Wikipedia;
A combination of low temperature and low relative humidity represents the optimum storage condition for cellulose acetate base films.
Adelstein, P.Z., J.M. Reilly, D.W. Nishimura, and C.J. Erbland. Stability of Cellulose Ester Base Photographic Film: Part II-Practical Storage Considerations. SMPTE Journal 101 no. 5 (May 1992)
http://en.wikipedia.org/wiki/Film_base
http://en.wikipedia.org/wiki/Cellulose_acetate_film
Anybody any ideas how to find something definitive on this? And are some acetate bases better than others? And how could anyone tell one from another?
One reason for freezing b&w film might be to prevent or slow decomposition as happens with the old nitrate base. It seems there a similar, albeit much longer term deterioration with acetate base material, with the same 'vinegar syndrome', shrinkage and embrittlement. The Image Permanence Institute quotes only 50 years! See Wikipedia;
A combination of low temperature and low relative humidity represents the optimum storage condition for cellulose acetate base films.
Adelstein, P.Z., J.M. Reilly, D.W. Nishimura, and C.J. Erbland. Stability of Cellulose Ester Base Photographic Film: Part II-Practical Storage Considerations. SMPTE Journal 101 no. 5 (May 1992)
http://en.wikipedia.org/wiki/Film_base
http://en.wikipedia.org/wiki/Cellulose_acetate_film
Anybody any ideas how to find something definitive on this? And are some acetate bases better than others? And how could anyone tell one from another?
