When I showed my results and recipes on the APUG forum it has been suggested that I could improve my Fixer recipe. Rudeofus suggests the following:
“C41 needs a very strong fixer and simply substituting Sodium Thiosulfate for Ammonium Thiosulfate will likely lead to retained Silver. If you really can’t get Ammonium Thiosulfate from anywhere in Australia, you should at least add Ammonium Chloride to your fixer recipe to boost it a bit. There’s a formula posted by Ole here, you will have to adjust pH of this brew to reach the pH 6.5 needed by C41. I recommend you skip the Metaborate suggested by Ole and use Sodium Metabisulfite to lower pH to 6.5.”
An update on the earlier post on mixing solutions which I thought was useful info….
In a recent APUG thread this issue of mixing very small quantities came up. Specifically in my C-41 developer the recipe calls for 1.4mg of Potassium Iodide (that’s “mg” not g) As most scales won’t measure such small units the answer is to make a diluted solution. This from stefan4u at APUG:
“Take one liter of aqua demin and add 1 gramm of Potassium Iodide. 1 ml of this solution will be 0.001g or 1 mg (1.4mg will be then1.4 ml).
Including all deviations in measurement this is the best / only way to do this at home…
Than take a small syringe and you will be able to come very close to the afforded ammount.”
And Polyglot from APUG puts it this way:
“Dissolve 10g (or whatever you can measure quite accurately) into 500mL then top it up to 1L, that gives you 10mg/mL. Mix it well, dilute it another 10x to get 1mg/mL and then measure 1.4mL into your developer with a syringe or pipette.”
I was beginning to wonder whether there was something wrong with my test shot so I did a quick develop in B&W chems and came up with a good images.
Then I remixed my Developer and Bleach from scratch and used Ilford concentrate for the stop bath.
Here then is my first test shot of C41 developed in chemicals mixed from scratch:
Dirty as anything but I’m ecstatic!
The ever helpful APUG forum has suggested a few things that I should try. Firstly it seems I need to up the sodium thiosulphate content in my Fixer and I need better scales it would seem.
Other things to check is the Glacial vs 28% acetic acid in the Stop and note a longer Stop time than I originally thought.
So, I’ve done 2 tests now. The first: I blew a whole roll. The neg was completely blank.
The 2nd I took a test roll, all the same shot and cut the neg into strips with a view to doing multiple tests. I bought some pH test strips to check. I had to adjust the pH of the bleach which I did with Acetic Acid. Otherwise the pH of my developer and fixer looked good.
I had a feint image come back with an extreme red cast and the bottom half of the neg was blank:
The trouble is I have no idea how to trouble shoot this problem. I may have to abandon the bulk mixing idea, which is a shame, and go with a tetanol kit.