There is a subtle difference between "divided development" and "two bath development" for films and the two terms should not really be used interchangeably.
In a divided developer, the developing agents are present in the A bath and the activator in the B bath. The pH of the A bath is such that practically no development takes place in the A bath.
In a two bath developer, some development may take place in the A bath since it is usually a slow working low alkalinity developer such as D-23. The B bath contains an activator which then speeds up the development process started in the A bath. In this system the goal is for bath A to provide density while bath B provides contrast.
Development of papers first in one developer (usually a low contrast one) and then in a second developer (usually a high contrast one) is termed "split development" and is something different again.
This ticket has managed to really muddy the water with regard to development.
Cogent and concise. I learned something, too.
Not so subtle water bath, no activator. Dan
Originally Posted by Gerald Koch
Any include developer may be no more than a technicality.
Originally Posted by juan
By no means should one assume that all that is needed for
development is a tray of carbonated water. Some very little
amounts are reported to affect contrast. Super coats with
DI may have so for the purpose of emulsion longevity.
My interest in testing for DI emulsions is to confirm
that there is present no amount sufficient to in any
way participate in image formation. Too easy to
test per my previous post. Dan