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 ))

 

[el wacho]

hi Relayer,

more speed ( essentially a little underexposure ) doesn't mean more grain. how did you come to that conclusion? phenidone is known as a developing agent that can give an extra stop. since you were making a diafine type developer, i thought it was one of the characteristics you were emulating. another one of the great properties of diafine is the keeping properties of bath A ( well over a year ). when you say the keeping properties are good, is it because you've stored a control bottle that you've tested, say, 6 months down the road? i suspect that 65g sodium sulfite is contributing substantially to the fine grain plus the shortish time of 3 + 3 and the borax.
sincerely, good luck with your experimenting. i really hope this ascorbate developer proves to be as stable as diafine. looking forward to your future reports on this developer.

 

[Relayer]

keeping properties of bath A (or any other developer) depended from a) pH b) amount of Sodium sulfite or other antioxidant (by example hydroxylamine in some color dev). in true-two-bath developers bath A have low pH (~6.5-7) and developing can't start in bath A. low pH increase storage life of bath A. sodium ascorbate also working as slow antioxidant and with 65g/l of sodium sulfite extend life of solution. my experience tell me that developer solution with slightly acidic pH have very good keeping properties.

other interesting formula which work like modified Diafine is metol-ascorbate 2bath developer MCDD:

Bath A
Metol 5g
Sodium sulfite 60g
Sodium Ascorbate 10g
Sodium metabisulfite 5g
Water 1l

Bath B
Borax 10g
Sodium sulfite 35g
Water 1l

3min in each bath. give same density as PC-Diafine. but grain/sharpness/contrast is slightly more

 

[eSPhotos]

other interesting formula which work like modified Diafine is metol-ascorbate 2bath developer MCDD:

Bath A
Metol 5g
Sodium sulfite 60g
Sodium Ascorbate 10g
Sodium metabisulfite 5g
Water 1l

Bath B
Borax 10g
Sodium sulfite 35g
Water 1l

3min in each bath. give same density as PC-Diafine. but grain/sharpness/contrast is slightly more

I wonder if this formula works without ascorbate ... I think it does.
Without ascorbate it resembles one of many DD23 or DD76.

 

[Relayer]

I wonder if this formula works without ascorbate ... I think it does.
Without ascorbate it resembles one of many DD23 or DD76.

if you omit ascorbate this formula can't be working because acidic pH in bath A (5g/l sodium metabisulfite). many 2bath variation of D23/D76 really isn't true-two-bath developers because developing started in bath A. it's really lazy-split. by example you can put film in any stock (D76,D23,XTOL or other) for 30% less time than required and after this put film into alkali (borax, soda etc) for 3-5min. this is well-known method described in many books
in case of true-2bath developing can't start in bath A! you can put film in bath A for 3min ... or 15min without any differences in result

 

[Alan Johnson]

I have done some testing of Diafine-C with APX 100 film.
At 3 min +3min the negatives are thin, at 5min +5min ,slightly too dense and the EI greater than box speed.
Developing in 20 ml part A +500ml part B for 5min to simulate the effect of carry-over on the film surface, tank and reel gives a faint image apparently insignificant compared to 5min + 5min 2 bath development.
My conclusion is that Diafine-C is a true 2-bath developer, the first succesful one to be disclosed of the phenidone/ascorbate type.

 

[Relayer]

Alan, thank you for testing! really don't need to put film in bath A more than 3min. bath B very depended from agitation. I recommended 5 initial rotation and 2-3 rotation per min

 

[brianmquinn]

Just an FYI
Every 2 bath developer I tested showed some development in bath A alone.
Some gave slight developement and in some 2 bath formulas MOST of the development happened in bath A.
Daifine is one that only gives a very faint image in bath A if left in for only 3 minutes.
Try stand devlopment for and hour in Daifine bath A alone and you will get printable negatives.
Try it. Shoot off a sequence of 3 brackted shots, clip those off the end of your roll and toss them in bath A alone and wait.

 

[el wacho]

catechol in sodium metabisulphite as a bath A won't develop until the film is immersed in sodium hydroxide as a bath B will do all the development.

 

[MichaelMadio]

This is very interesting. I was going to try a 2-part phenidone/C developer myself with the main difference being no sulfite (I have had great success with PC sulfite-free developers). The recipe I had in my notes to try is as follows:

Part A:
Ascorbic Acid - 6g
Phenidone - 0.15g
Sodium Bicarbonate - 3g
Water to make 1L

Part B:
Borax - 20g
Water to make 1L

I use the same amounts of Phenidone/Vit-C/Borax in a L of water to make a 1-part developer that works well and lasts a very long time (bottle over 6 months old works like new). I have no idea how/if this version works but I will report back when I find out.

 

[albada]

This is very interesting. I was going to try a 2-part phenidone/C developer myself with the main difference being no sulfite (I have had great success with PC sulfite-free developers). The recipe I had in my notes to try is as follows:

Part A: Ascorbic Acid - 6g; Phenidone - 0.15g; Sodium Bicarbonate - 3g; Water to make 1L
Part B: Borax - 20g; Water to make 1L

I use the same amounts of Phenidone/Vit-C/Borax in a L of water to make a 1-part developer that works well and lasts a very long time (bottle over 6 months old works like new). I have no idea how/if this version works but I will report back when I find out.

Michael, did you get around to trying this? Did it work?

Mark Overton

 

[bwfans]

Any comments on the storage, shelf life and the capacity compare with Diafine?

 

[analog what is that?]

This has now been verified in a slightly different formula over here in close cooperation with Michael, the results of which will be published shortly in our blog, illustrated and notes during the experiment phase.

 

[albada]

This has now been verified in a slightly different formula over here in close cooperation with Michael, the results of which will be published shortly in our blog, illustrated and notes during the experiment phase.

That's good news, and I'm glad to hear that this idea is being pursued to a conclusion.
Please post a reply here when you add your results to the blog.

Mark Overton

 

[Alan Johnson]

Any comments on the storage, shelf life and the capacity compare with Diafine?

My Diafine-C,kept under inert gas, is now 5 months old and works OK. I prefer the results from 5min+5min.
It seems to be the accepted wisdom that in part full bottles hydroquinone based developer (Diafine) will oxidize more slowly than ascorbate (-C version).
Diafine-C works well in expose for shadows contrasty situations.

 

[gorbas]

Nice results Relayer! Hard to tell from this small pictures, but Diafine C grain looks "mushy" - not well defined or sharp?
In the past I used Tetenal Emofin and Difine. With Emofin I had way better results. But it's hard to find developer, even in Europe.