Film Base

Rollei ATP

plot of mid infrared transmittance of Rollei ATP film

Rollei Ortho 25

plot of mid infrared transmittance of Rollei Ortho 25 film

The base of a film and unexposed emulsion may look clear; but, some film is more clear then others. For example; Rollei Ortho 25 has a uniformly clear base across the entire visible spectrum.  TMax is also uniformley clear; but, the amount of transmittance is lower.  The maximum transmittance of TMax is 58% while the maximum transmittance of Rollei Ortho is 70%.


Note: These scans were produced on an HP 8450A UV-Vis Spectrophotometer and plotted using an HP 7550 pen plotter.  Both pieces of equipment were manufactured in the early 1980's.

There is a good piece of software called GraphClick which will interpret scans of plotted data and extract the data points.

Copyright 2015 by Mark Gavin