Share My CD Black and White Developer

fert

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I would like to share my own CD b&w developer:

Sodium sulfite: 100g
Sodium ascorbate: 4 grams
CD-1: 5 grams
Borax: 5 grams
Boric acid: 1.5 grams
Potassium bromide: 0.6 grams
Add water to 1L

So far I tested out two films, Ilford pan400 stock/6mins, Kodak double-x/3+2/6mins. the rest of the films still need to be adjusted in terms of time, for example, kentmere pan100 stock may be at 5mins. kentmere pan100&Ilford pan400/3 +2/7~8mins.

The recipe is very similar to A49 but the development time is much shorter. (I don't know how to name it, hopefully people can help me out).
Added down are sample images and data, the sample images are from Ilford pan400 and the data is done peeled:


 

Donald Qualls

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I presume 3 + 2/6 minutes is the same as three minutes and twenty seconds?

I don't see CD-1 around much in the USA -- CD-3 and CD-4 are much more common here (because they're the current developing agents for C-41, E-6, and RA-4).
 
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fert

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china
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Donald Qualls said:
I presume 3 + 2/6 minutes is the same as three minutes and twenty seconds?

I don't see CD-1 around much in the USA -- CD-3 and CD-4 are much more common here (because they're the current developing agents for C-41, E-6, and RA-4).
Click to expand...
Oh no, the slash is just there as a separator, it's actually 3 parts stock original with two parts water, developed for 6 minutes.CD-1 Maybe you can get it from China, it's still very affordable on my end, about $45 for 500 grams of CD-1.
 

Alan Johnson

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fert said:
I would like to share my own CD b&w developer:

Sodium sulfite: 100g
Sodium ascorbate: 4 grams
CD-1: 5 grams
Borax: 5 grams
Boric acid: 1.5 grams
Potassium bromide: 0.6 grams
Add water to 1L
Click to expand...
IIRC this is the first CD-ascorbate developer to appear on Photrio.

Ryuji had some Dimezone-s ascorbate and Metol ascorbate developers and added Salicylic acid and TEA to slow down oxidation due to the catalytic oxidation of ascorbate by iron and copper impurities:
 

John Wiegerink

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I'm no chemist and what I learned in high school chemistry class is long gone, but I believe one could swap out the CD-1 for CD-3 or 4 if you figured out the mole for mole weights. I'm going to search around to see if I can find CD-1 here in the good old US of A. I have bought and still have some CD-4 that I think I got from Formulary.
 

Milpool

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fert, have you tried this developer without the ascorbate?

Is ascorbate superadditive with PPD or derivatives such as the CDs? If not, I wonder if it is doing anything in this pH range.
 

John Wiegerink

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koraks said:
No, you'd have to determine the relative development potency. A mole per mole substitution won't cut it.
Click to expand...
Koraks,
At my age my memory isn't the best so I could be wrong on what I'm about to say. I seem to remember being in on a discussion involving the substitution of one CD form for another with Gerald Koch. I also believe you were in on that discussion too, but I could be wrong. Anyway, I can't really remember what was said, but I swear Gerald talked something about mole weight. Heck, I don't know for sure since I can't even remember where I put my reading glass anymore. Whoops, they're
on my head.
 

Alan Johnson

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Milpool said:
Is ascorbate superadditive with PPD or derivatives such as the CDs? If not, I wonder if it is doing anything in this pH range.
Click to expand...
It seems the function of the ascorbate may be to remove the oxidation products of the CD:

How is C41 developer differnt from B&W?

If the job of the developer is to turn silver salts to metal, which is (my understanding) identical between color and B&W, what is the difference between a C41 developer and a B&W one? Of course I can just grab a roll of Gold 200 and process it in Xtol heated to 100F, to see what happens. (and...
www.photrio.com
 

koraks

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John Wiegerink said:
something about mole weight
Click to expand...

Mole weight is in there somewhere, but the different CD's are certainly different in terms of developer activity. The difference between e.g. CD3 and CD4 is also quite distinct. There may furthermore be differences under specific conditions (e.g. various pH's). I really couldn't say off the bat how much CD3 or CD4 you'd have to substitute in this formula to get the same development speeds.
 

John Wiegerink

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Understand!
 
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fert

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china
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Milpool said:
fert, have you tried this developer without the ascorbate?

Is ascorbate superadditive with PPD or derivatives such as the CDs? If not, I wonder if it is doing anything in this pH range.
Click to expand...
For this recipe, I tried using 3 grams of hydroquinone II not sodium VC at first. After comparing later, the DMAX will be higher with sodium VC than with hydroquinone if used for the same amount of time.
 
  • fert
  • Deleted
  • Reason: misquote
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fert

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Oct 2, 2023
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china
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In the last few days I've done tests on different films, here's some development time, to be followed by tests on foma 200, ilford delta100/100, HP5, Svema Foto100/200 and FN64.
 
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fert

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Oct 2, 2023
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Location
china
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35mm

Yes, adding 1 gram of salicylic acid is very advantageous for preservation of the configured working solution. However, it is not necessary if used immediately.
 
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fert

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Oct 2, 2023
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Location
china
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relistan said:
@fert very interesting, and nice results!

Regarding availability:
CD-1 is often available on eBay. Note that the toxicity is higher than the other CD series.
Click to expand...



Yes, it is still imperative to be safe in your use.
 
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