Monday, October 31, 2011

Phenidone/Ascorbate

It's been a while since Michael first wrote a piece about phenidone developers here.
He strongly urged me to try this, and a few months back I secured 100 gram of the good stuff.  However unforeseen events on the national level that impackted me / my family took the drive away from doing experiments, we had more than enough with getting back to a normal life after tre tragic bombing & shooting here this summer.
But life goes on and I was also fortunate enough to connect with amnother photographer living here, that has started doing caffenol. We got together, swapped stories & experience (and a couple of cameras, collectors are like stamp collectors, there are always a duplicate in a dark corner....).
I suggested he band together with me in an experiment I've been contemplating, and here goes.

We have decided to share the burden and split the mix between us, so that we test separate films, this way we will be able to build experience quickly.

The plan is to test out 4 or 5 different recipes, developers based on Vitamin C and Phenidone, based on different types of alkali.  Up until now I does the mixing and have control over the recipes, but Trond is the more active testing the stuff quickly and prescisely, making valuable observations and reporting back.

He was the first out of the starting blocks, with a Foma 100 film, and have shown pictures on Flickr, hopefully they will be shown here in a few days.

The recipe so far is based on Patrick Gainers work, adapted and tweaked a little, to adapt to what is available here.

Michael - cowriter on this blog, also have a recipe shared here, it will also be tested by us, so we have cross-references.

The first recipe is very simple :

Washing soda (anhydr.)          5,71 gram
Ascorbic Acid                         2,11 gram
Phenidone                                0, 021 gram

This is broadly what Gainer termed his Standard recipe, what we should call it, I call it
FenoBate 52.002  which gives me a hint on the recipe used, but the name is not important, I'm standing on gainer's shoulders here, he is the inventor.

What is interesting and should be noted is that the whole idea here is very simple :

This is a stock developer to be used many times, developing time increased after every use, like good 'ol D76.  Instead of using Sodium Sulphite to protect the developing agent from oxidizing, one of the developing agents themselves, namely Ascorbic Acid does that, as long as it is present in excess in the solution, phenidone is protected, the rest of it is very simple Ascorbic Acid is hydrolysed into Sodium Ascorbate by the Soda, just like Caffenol, and the soda secured a basic working environment, like caffenol.
Developing time has been the only small problem, it was suggested to use the same time as D76, this has turned out to being a little imprescise. opne problem here might be that Kodak themselves altered D76 times a few years back, creating uncertainity.

First test was Trond with Fomapan 100, exposed at box speed with a some frames exposed 1 step over and one step under.

His exact data and pictures will be incvluded here.............

My first try was  was Kodak Gold 200 which is a C41 color film, my usual test vehicle.

Since Tronds experince from the first film suggest that he should have given the film a little longer time, I adjusrted the base time accordingly.

Base time B&W film (2. test)   9 minutes @ 20 C
Adjusted for C41 film (experience from Caffenol here)  12 minutes @ 20 C

Standard agitation regime, slow inversions for the first minute, with vigorous shaking to expel any air bubbles, then 3 slow inversions per minute at the top of the minute hand.

Stop bath : 2 changes of clean, plain water, NOT acidic stop bath for a soda-based developer!

Standard fix in a rapidfixer, and normal wash.

Make a careful note : this developer has no restraining agent, no anti-foggant and does not need one, so far  (Fomapan, Gold 200, Shanghai 100, Ilford FP4 so far)

The result from my first film, Kodak Gold 200 :

Simple unaltered scan of 3 negatives, from left to right :
Box speed (200 ISO), 1 stop under, 1 stop over
To me it seems Box speed and 1 stop over is best, indicating a slight over-development.


The 3 pictures in detail  :

Straight scan, box speed (200 ISO) 9 min @ 20 C

Same exposure, contrast and saturation enhanched 1 step

 
Underexposure one step :

Straight scan, 1 step underexposure (400 ISO) 9 min @ 20 C

Same exposure, contrast and saturation enhanched 1 step

 
Overexposure 1 step

Straight scan, 1 step overexposure (100 ISO) 9 min @ 20 C

Same exposure, contrast and saturation enhanched 1 step

Some more picture triplets :





5 comments:

  1. Glad to see you have this up. Regarding the dev times, you will notice that the recipe used is from Patrick Gainer's earlier work. After more experimentation he found that increasing the Phenidone to a ascorbic acid/phenidone ratio of 40:1 was the sweet spot for activity and my testing shows the same. If you use Phenidone at 0.05g/L vs the 0.02g/L above I think you will find the dev times will be closer to D-76 times. Also remember that those are just starting points. My data shows that Phenidone at 0.02g/L is on the downward slope of activity so bear that in mind while testing.

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  2. That is exactly what I discovered Michael. It needs a bit more time than D76. About 35-40 more time, but given that increased time, the developer works just great.
    I'm in the process of scanning a Fomapan 100 developed at 8.5 minutes baseline.
    Will posts results when they are ready.

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  3. Out of curiosity, why such odd quantities in the recipes? Your recipe is:

    Sod. Carbonate - 5.71g
    Ascorbic Acid - 2.11g
    Phenidone - 0.021g

    Why not simplify it as follows:

    Sod. Carbonate - 5g
    Ascorbic Acid - 2g
    Phenidone - 0.02g

    Practically I don't think it makes much difference but I'm curious to know your rationale and thought process as I would like to learn from this as well.

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  4. To answer your question Micheal : I live in a metric country, trying to dechipher US measure recipes into something comprehensible is hard enough, if I havn't got to remember to make them look sane also, after the fact!

    I guess I could, and I guess I will, eventually, but for now I'm concerning myself with crosschecking things, so I don't need no more confusion!

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  5. That's what I thought. Much of what is written about this is unforunately inconsistent as there are references with metric units, US imperial units, grains, etc. I'm sure it will all be sorted out eventually and in metric please ;-)

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