Quote Originally Posted by glbeas
The first bath soaks the emulsion with one part of the developer, I think the activator part like Metol, then it is transferred to the second part with the alkali to make it work.
This is what the books say but did you ever try to "soak" the film in bath A and fix it afterwards leaving out bath B? I did this unintentionally (doh!) with the Stöckler formula but, big surprise, the only thing missing was a bit of shaddow density.

Honestly It wasn't that much of a surprise as I previously read an arcticely about the Stöckler formula written by James Kates who took the time to really dig into this field and do some densitometry. To summarize his results: most of the development happens in bath A, bath B intensifies the shaddows. Curve slope of midtones and highlights can be adjusted by time in bath A. Zone system methods can be applied.

Here is the link, it is well worth reading:

Obviously with the two-bath formulas still in use today like Barry Thorntons's Metol two bath, Divided D-23, Divided D-76 (you name it), the high amount of sulfite provides enough alkalinty for the development to take place. On the Pure silver list I asked for forrmulas where this might not be the case. The formulas that turned up where obscure at best.

Stefan (still repeating myself...)