. fiCZ, YEARS Fig. 3. Shrinkage vs. age for triacetate and nitrate prints scrapped afte- normal theater use. Measurements made at 70 F and 50% |Q4 !„_ o a Fig. 4. Average rate of shrinkage of processed triacetate 39aim motion-picture positive film at 90 F and 90% Con- trolled tests on strips freely exposed to circulating air; all meas- urements made after reconditioning at 70 F and 50% Kodak aerial films are now coated on two bases. Kodak Aerographic films, (Type lA) are made on low shrink topographic base, suitable for use in accurate mapping work. Regular Safety Aero base is u
. fiCZ, YEARS Fig. 3. Shrinkage vs. age for triacetate and nitrate prints scrapped afte- normal theater use. Measurements made at 70 F and 50% |Q4 !„_ o a Fig. 4. Average rate of shrinkage of processed triacetate 39aim motion-picture positive film at 90 F and 90% Con- trolled tests on strips freely exposed to circulating air; all meas- urements made after reconditioning at 70 F and 50% Kodak aerial films are now coated on two bases. Kodak Aerographic films, (Type lA) are made on low shrink topographic base, suitable for use in accurate mapping work. Regular Safety Aero base is used for Kodak Ektachrome Aero film, and Recon film. The latter has somewhat higher shrinkage characteristics than the Type lA. A comparison of dimensional changes in the two bases is shown in Table VII. Since 1941, Type lA (topographic) film base has been made from cellulose acetate butyrate. Between 1938 and 1941, it was made from cellu- lose acetate propiomate. Both these bases have substantially lower humid- ity expansion coefficients than cellulose acetate, used prior to 1938. 264
Size: 3155px × 1585px
Photo credit: © The Bookworm Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookcollectionameri, bookcollectionbiodiversity
