Rodinal is an odd developer; it is rather high pH since it uses
potassium hydroxide as the accelerator. When diluted the pH is somewhat
lower or at least it does not swell the gelatin as much. There are
formulas in the literature for making "authentic" Rodinal but none has
any indication of source. Rodinal was one of the first packaged
developers. It became avaiable more than a century ago. It is a very
convenient developer but not the optimum since it tends to produce more
grain and less speed than more modern ones. When diluted it becomes a
compensating developer and at some mid-dilution will exagerate edge
effects.
It is suspected that AGFA changed the formulation at least once
and maybe a couple of times during the life of the product. No one knows
for certain since it was always a proprietary formula and method of
manufacture.
Despite not being "optimum" it will develop anything and tends to
be low fog.
On 4/17/2015 10:47 AM, Dennis wrote:
On Apr 17, 2015, at 10:20, Snoopy <snoopy@xxxxxxxxxxxxxxx <mailto:snoopy@xxxxxxxxxxxxxxx>> wrote:
Rodinal was called the "developer for grain lovers", somewhat unjustly I
hasten to add. If you use Rodinal in weaker diltions (1:50, 1:75, 1:100)
it is a very nice developer and acts as a balancing/compensating
developer. I find the recommended dilutions of 1:10 or 1:25 as too harsh
and grainy.
Isn’t that counter to logic, in that the more dilute developers generally give sharper and more evident grain?
I generally use the late version Rodinal at 1-50 and it is definitely grainy.
Dennis
