Barry Thornton 2 Bath - how to adjust for finer grain?

[Harry Lime]

In light of all the recent talk about this developer I have a question that perhaps some of the more chemistry adept members can answer?

How would you adjust the formula to achieve finer grain i.e increase the solvent action?

Thanks

Bath A
80 g sodium sulfite
6.5 g metol
Make up to 1 L with water

Bath B
12 g sodium metaborate (Kodalk)
Make up to 1 L with water

 

[Harry Lime]

thanks.

Does DD23 deliver full film speed? 400asa out of Tri-X?

thx

 

[Relayer]

use bath B with next formula:
Borax 10g
Sodium sulfite 30g
Water 1l
this formula allow reuse, because sulfite. give less contrast and fine grain

 

[David Allen]

I can't imagine why you would need finer grain with BTTB developer as I find it the perfect balance between fine grain, speed and contrast.

However, if finer grain is your requirement you should increase the Sodium Sulphite to 100g and replace Bath B with Borax (i.e the Stoëckler formula). However, the trade off will be lower contrast and loss of speed.

Best,

David
www.dsallen.de

 

[presspass]

Also look at Anchell & Troop's TD-201. It uses a less metol and more sulfite in Bath A and a combination of borax and metaborate in the second bath. Fine grain, good compensation and film speed, and sharp.

 

[Harry Lime]

Thanks everyone. I'll play around with these suggestions.

 

[Gerald C Koch]

The granularity of a film is determined by its formulation. Highly solvent developers can reduce the graininess but at the cost of reduced resolution and speed. Two bath developers with their emphasis on edge effects tend to enhance graininess. If fine grain is your goal then these developers are not a good choice. A developer like Perceptol might be a better shoice.