Cutting Sodium Sulfite: compensate with more Borax?

[Jarin Blaschke]

Hio there:

In my further experiments with D96, I'm trying a version with 20g instead of 75g of Sodium Sulfite per liter to increase acutance. I understand that Sodium Sulfite is slightly alkaline. For my first trial, should I up the Borax to compensate? Increase development time? I don't have a ph meter.

Thanks.
-Jarin.

 

[BradS]

Only change one thing at a time. Otherwise you won't know if the effect (if any) is due to the decreased Sulfite or the increased Borax or some combined effect.
The Borax is gonna act as a buffer...it will hold the Ph pretty close to 9 (if I remember correctly).
The published formula for D-96 looks pretty optimal to me...do the experiment but be prepare to be underwhelmed.
The effect of the sulfite in D-96 is complex. It is a mild silver solvent, an alkali, and it prevents the film from staining.

 

[Jarin Blaschke]

Well, I just mixed it with 20 g of sulfite and 4.8 rather than 4.5g of Borax. Time, temp and agitation the same. We'll see if it gets any sharper. I'll report!

ps: keeps it from staining? Or oxidizing?

 

[Jarin Blaschke]

Well, the film is up to dry and yes, there was some loss in activity compared to the regular d96 test negative of the same shot. I may take the developing time from 6:45 to 7:30 or 7:45 next time.