Originally Posted by Jorge
I beg to differ. The measurement charachteristics is important and is usually indicated with the technical data (and is the reason why you can change the aperture on some densitometer models). The Callier Effect will not change the basic shape of the caracteristics curve (well - there are people, who believe it does), but it will for sure change the grade. This is the reason why you usually have different development times for condensor and diffuse light enlargers. You may, of course, apply arbitrary correction factors in this case. But this would indeed be "against every principle of sensitometry". The Callier Effect depends on light aperture, grain size and grain shape and you will need different correction factors for different types of film/developer combinations. To be exact, you would have to calculate backwards from paper densities to receive the desired negative densities you should tune your development process to.
There is a good document about this availiable under: http://www.gigabitfilm.de/download/callier_effekt.pdf (esp. the second part about the different measurement geometries on transparent targets)
Unfortunately, it is written in German, but some translation program might help.