Diafine revisited: Ascorbate version

[Relayer]

I was made some experiment with Diafine formula and replace 6g of Hydroquinone in bath A to 10g of Sodium Ascorbate. so my formula of Diafine-C:

Bath A
Sodium sulfite 65g
Phenidone 0,2g
Sodium Ascorbate 10g
Sodium metabisulfite 5g
Water 1l

Bath B
Borax 10g
Sodium sulfite 65g
Water 1l

usage 3min in each bath. results is very good - really less grain
HP5+ @400, scan 2400dpi, left Diafine-C, right - Diafine

[el wacho]

great results.

does it give the speed increase with the borax?
what are the keeping properties of bath A?

[Alan Johnson]

Phenidone at 0.01g/L is a slow developer.Can you verify that you are not just getting development in bath B due to carry over of bath A on the film surface,tank and reel rather than due to developer absorbed in the emulsion?

[Relayer]

great results.
does it give the speed increase with the borax?
what are the keeping properties of bath A?

yes, compare to original PQ version ascorbate produce more dense negatives. I can't talk about speed because when we rate film as more speed we have more grain
keeping properties of bath A is very good because low pH.
formula for Diafine I found in Steve Anchell "The Darkroom Cookbook"

[Relayer]

Phenidone at 0.01g/L is a slow developer.Can you verify that you are not just getting development in bath B due to carry over of bath A on the film surface,tank and reel rather than due to developer absorbed in the emulsion?

Phenidone is 0.2g/l, not 0.01g/l ))

[Alan Johnson]

I mean that due to carry over on the film surface,tank and reel the phenidone concentration in bath B may be such as to produce the image,it may not be due to phenidone absorbed in the emulsion and therefore not true 2-bath development.
Just pour 20ml bath A into 500ml bath B and see if this will develop the film,if so it is not 2-bath development.

[Relayer]

I mean that due to carry over on the film surface,tank and reel the phenidone concentration in bath B may be such as to produce the image,it may not be due to phenidone absorbed in the emulsion and therefore not true 2-bath development.
Just pour 20ml bath A into 500ml bath B and see if this will develop the film,if so it is not 2-bath development.

Alan, my experiments with 2 bath developers not confirm this. I was try more than 10 different 2 bath developers and 2nd bath isn't one-shot (sometime I make fresh solution). always I get same result from each developer.
3min in 2nd bath is very small time and developing going only in film surface

[Relayer]

some interesting fact:
20ml of any stock (D76, D23 or other) + 1g Sodium carbonate + 300ml of water require 20-25min for developing HP5@400. compare this time with 3min in borax alkali (as bath B).
if you add 20ml of bath A into bath B and put film to bath B (skip bath A) for 3min - you have blank negatives - trust me ))

[Alan Johnson]

Well you are claiming to have made the first ever successful phenidone ascorbate 2-bath developer.
A serious scientific claim requires more evidence than "trust me" IMO.

[Relayer]

I'm not a "scientific". you can simply try this formula instead posting abstract theory here ))