[Leica] b/w processing: big shifts

[firkin at ncable.net.au (Alastair Firkin)]

Well, I have fiddled with getting processing standardized for years,  
but now I have the set up to do it right, and I finally found a  
second-hand 205FCC with the zone system, so this week end I fired up  
the Densitometer and began testing film.

I started with APX 25 in Rodinal 1:50. Nightmare. By the time I'd  
finished I discovered that the true rating of this film in my camera  
system is ISO 8. I also discovered that my processing times were  
quite a bit tooooo long, so I moved to FP4+  in ID11. Well the final  
outcome of that was that the rating of the film was 2/3 stops slower  
than the 125 ISO and the processing time was 60% less than recommended:

I know I should have done this stuff a long time ago, but I never  
thought it would be so far out of "normal". Is this why so many  
people recommend doing these rather boring, time consuming and  
expensive tests ?

So the weekend is over and I have a new set of processing times for  
APX 25 and FP4+. I need to test a 400 ISO film next: the things we do  
for our "art" ;-)

Hope you had a more productive weekend

Cheers

Alastair