William Robb wrote:
The problem with any extrapolated test, be it Wilhelm's method, which is decidedly harsh, or Kodak's, which is not really a longevity test at all, is that neither one real
tells you anything.
Wilhelms method tells you tat if you pump 450 lux into a print for 12 hours per day, it will start to fade after X number of days. Nothing else. Nada.
Can see you not into materials testing. Guess we can forgo testing contstruction in the future.His methods don't reflect how prints are treated in the real world, and cannot be used to judge anything, beyond comparing how different materials react to his testing procedures.
Opinions from left field are interesting but not very constructive. Of course if you have material performance data that refutes Wilhelms work, it would be of some interest.
Otis Wright
Regarding cost of 100 speed film to 800 speed film, I doubt very much if it costs more to make one than another, at least not an appreciable amount.
William Robb
