Thursday, March 24, 2011

Tylenol and ascorbate - an addition

Adding to Erik's post about tylenol and ascorbate, I do have some success with this but it still needs work.  I use parodinal with vitamin-c and borax to make a pretty good developer.  Advantages over straight parodinal are less grain and working strength solution longevity.

I use parodinal from Donald Qualls as follows:

Water - 250mL
Acetaminophen - 15g
Sodium Sulfite - 50g
Sodium Hydroxide - 20g

Mix in order indicated, let stand in sealed container 72 hours before using.  Keep crystals from bottom of container with liquid when decanting, stir before drawing off concentrate for dilution.  Use dilutions and times as for Agfa Rodinal.  Use within 30 minutes of dilution.


To make RCB (Rodinal / Vitamin-C / Borax), I use the following:

Borax Saturate Solution - 400mL
Ascorbic Acid - 6g
Parodinal - 40mL
Water to make 1L

This developer is quite active with good speed and relatively fine grain.  The grain with normal development is about the same as PCB with minimal agitation.  This is much better than my current best with Caffenol-C and much better than normal rodinal development.  There is no fog.

Here is a sample from the "corner of horror":



This is Tri-X, EI 400, in RCB for 7:30 @ 19C with normal agitation.

The working strength solution has been in a closed bottle for 2 weeks now and shows the same level of activity.  As with PCB it appears that the ascorbate is preserving the p-aminophenol.  I found that using parodinal like normal and adding ascrobate increases activity but causes significant fog.  I also found that using parodinal like normal with borax significantly reduces activity (expected ... lowers pH) but improves grain.  I figured that ascorbate would maximize activity and adding enough borax would keep the pH down for good grain and I got RCB. 

My only real complaint with this is the use of sodium sulfite as this is still a somewhat specialized photo chemical and it would be nice to do without it.

MM
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5 comments:

  1. Most interesting and EXACTLY what I was hoping for!

    So you mix your erzats-Rodinal with Borax and Vitamin C? Hmmmmm that sounds like a plan, most likely you could pre-mix the Borax Vit C also, have you tried that?

    And the time/temperatures, where do you find/get them or is this forgiving like Cafenol?

    Sodium sulphite IS a problem - I haven't found it locally, and will have to bite the bullet, ordering it from overseas.

    Keep your pictures from your corner of horors coming! It is VERY interesting to comnpare how the different developers render this motif, even if I gather the lightning conditions plays tricks on us....

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  2. Pre-mixed borax and vitamin-c works well and I use it often. Patrick Gainer had that idea, I tried it, and found it works. As for times, I guess ;-) I see how long it takes to blacken a piece of unprocessed film and try at 3-4 times that. I take a series of bracketed exposures to determine usable EI for that combo.

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  3. I see you have studied your Gainer well!

    It is amazing that ascorbate in solution works contrary to what most people think! All this talk about death, one-shot developers etc etc, and all the talk about smell of coffe - all this have created some sort of myth that Cafenol is something else than a quite fine developer....

    However; I need to stock up on chemicals, I can see now I need to take this to the next level. I'll definitely try out PCB the soonest and PaRodinal has been om my short-list for a loong time, if ever my old AGFA bottle of Rodinal empties itself! :-)

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  4. I am somewhat a student of Mr. Gainer. I have read much of what he has posted and have studied it in great detail. The idea of really simple high quality developers intrigues me and I think ascorbate developers are a very practical solution. I'm sure you will like PCB.

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  5. I just tried another variant and have an active developer without sulfite (Tylenol / Vit-C / Borax). I will test tomorrow and post my results.

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