This is very interesting to me as well. Is the Bond information on method and/or your analysis published anywhere? I'd love to see it.

Robert Reeves, in chapter 7 of "Wide-Field Astrophotography", (ISBN 0-943396-64-6) offers a technique for determining reciprocity law failure characteristics of film. You set up a gray card (and gray scales/color patch charts as preferred) to shoot at 1/8 second, then put on an ND 3.0 filter and shoot exposures for 128 seconds at varying apertures with the same illumination. You find the amount of failure by measuring negative density on the long exposures relative to the baseline 1/8 sec exposure. This obviously works off failure factor data much further out than 1 second, and perhaps is more applicable to pinhole shooters and astrophotographers. But the method is sound and interesting. The aim in astrophotography is to find suitable films that have the least reciprocity failure and least color shift in the very long exposures used. Spectral sensitivity is also an issue in that application.

I'm curious about the method used by Bond, and the range of exposure lengths covered.

Lee