Another Antifoggant Question...

[martellsv]

I'm thinking to use in Lith developer Benzotriazole (BTAZ) instead of KBr, but replacing the contents when exhausted. I don't know how much BTAZ replace each certain number of prints. is there a method, a calculation, or a rule?.

I Read that in some developers KBr do not accumulate, for example when used with several prints, therefore i unsderstand that is neutralized and it has no effect in the next print. Is this correct? How it works?

Thanks

Alejandro Martell from Salamanca

 

[Rudeofus]

As you develop prints, insoluble Silver Bromide gets converted into metallic Silver and Bromide, and the latter goes into solution in you developer. As this happens the developer becomes more and more restrained due to Bromide buildup. Whether you use BTAZ or Bromide in your original formula doesn't matter much. I have read on several occasions that Phenidone/DimezoneS is less sensitive to Bromide which means you could formulate a print developer based on these and some secondary dev agent (Hydroquinone, Ascorbic Acid, ...), and Bromide buildup won't matter as much.

 

[Ian Grant]

Part of the Lith printing process is the colours of the highlights adding Benzotriazole will kill that and it's dependant on a rewasonable level of Bromide, this builds up as a developer gets used.

Ian