RD-201: Phenidone-Pyrogallol true two bath

[Relayer]

Hello

Phenidone with pyrogallol is superadditive and allow to make true two bath developer. Bath A have low acidic pH and developing start only in bath B. Developer increase speed by 1 stop and produce very sharp images.

RD-201 developer
Bath A
Sodium sulfite 50g
Phenidone 0,2g
Pyrogallol 6g
Sodium metabisulfite 6g
Water 1l

Bath B
Sodium sulfite 30g
Sodium carbonate 15g
Water 1l

Developing time 3min in each bath.

Polypan F50 @64

HP5+ @400

 

[el wacho]

great work!

does it stain / tan? just curious if the sod. sulfite prevents this.

what would your opinion be about reformulating for catechol ( substituting the pyro )?

have you looked to see if there is any development in A bath?

i ask this because i once tried to formulate a metol only A bath with sod. metabisulfite 6g/Litre as the preservative. i used sod hydroxide as the B Bath. i increased the metol to 18g/Litre (from 8g ... gram by gram ) and only just started to get a faint image. i abandoned that idea because i could think of better formulas that used less metol.

congrats on your formula.

 

[Relayer]

does it stain / tan? just curious if the sod. sulfite prevents this.

it doesn't stain because sulfite in 2nd bath. but it will produce some stain if you omit sulfite. note that in this case 2nd bath is more like as one shot

what would your opinion be about reformulating for catechol ( substituting the pyro )?

phenidone+catechol is less active that P+Pyrogallol
you can try next formula

bath A
Sodium sulfite 50g
Glycine 5g
Phenidone 0.2g
Catechol 5g
Water 1l

bath B - sulfite+carbonate. 3min in each bath

have you looked to see if there is any development in A bath?

after 3min in bath A no any image

congrats on your formula.

thank you

 

[pentaxpete]

Thanks for posting this -- I have all those chemicals and will try it out - I suppose you mean the Anhydrous forms of the Sodium Sulphite and Carbonate NOT the Hydrated forms ?

 

[Gerald C Koch]

A suggestion for further experimentation. Pyrogallol in the presence of sufficient sulfite behaves in much the same manner as metol. The Nietz-Tschibissoff series places them next to each other and their redox potentials are very similar. This would indicate that metol provides an effective substitute that is far less toxic, cheaper, and more stable than pyrogallol. This pairing of phenidone and metol is what Tetenal does in Neofin Blue.

 

[Relayer]

Thanks for posting this -- I have all those chemicals and will try it out - I suppose you mean the Anhydrous forms of the Sodium Sulphite and Carbonate NOT the Hydrated forms ?

sulfite and carbonate is anhydrous

important note about 2nd bath: don't try to use borax! you will have blank film, because borax pH is very low.

 

[albada]

Thanks for creating this developer and posting your results.
A couple of questions:
1. Have you done keeping tests, to see how long the developer will last? (6 months or more?)
2. You said 1-stop speed increase. Do you have an accurate way of measuring the speed-gain?

Anyway, good work!
And good pictures also. You are a good photographer.

Mark Overton

 

[Relayer]

1. Have you done keeping tests, to see how long the developer will last? (6 months or more?)

now it keep ~3 month without any loss of performance. I think that developer can be keeping ~1year because acidic 1st bath

2. You said 1-stop speed increase. Do you have an accurate way of measuring the speed-gain?

sorry, no. maybe I'm wrong, but negatives slightly dense than I like

 

[nworth]

Pyro produces a very nice (and unique) "look" regardless of staining. That is a good objective for a developer like this, and it is a reason not to substitute metol or catechol. With 6 g of metabisulfite, I would think the A bath is pretty close to neutral. That means it probably doesn't have great life, but it should be reasonable. I don't know if making it more acid would help, but it might.

 

[Gerald C Koch]

Pyro produces a very nice (and unique) "look" regardless of staining.

Unique, how do you know? Have you conducted blind evaluations with a group of people for various developers? We often see what we think we should see. Sorry but it's human nature.

Producing a good print depends on the skill of the individual rather than in any "magical" properties of a particular developing agent.

 

[Relayer]

Kodak 5222 Double-X @800 in RD-201 3+3 min
body: Olympus OM-4, lens: Vivitar (Komine) Close Focus 2/28 @11

 

[jim appleyard]

Thanks, Relayer. good images. You sure do like to play with your chems!

I'm not sure I'll ever get to try this as I've finally whittled my devs down to a special handful, but it never hurt to keep another on file.

 

[StoneNYC]

Saw this on the RFF on the XX thread, and came here, so thanks.

Can I buy all these chefs at the Photographers formulary?

I've never mixed my own and haven't done any chemistry since I was a kid but I've been looking for a substitute for Neopan 400 and the fact you can get such results from XX shot at 800 is astounding with such smooth results, I will say that it was outside in the sunshine, so i wonder how it would do inside, but still it's promising.

So yea where can I buy all the chems and do they come in the proper storage containers or do you have to buy those separately?

About how much for minimal stock of all of this stuff?

Thanks.


~Stone | Sent w/ iPhone using Tapatalk

 

[Relayer]

You can buy all chemicals required for this developer in PF.

 

[StoneNYC]

You can buy all chemicals required for this developer in PF.

Sweet, thanks.


~Stone | Sent w/ iPhone using Tapatalk