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Instant Mytol Recipe

Yeah, I would also be fascinated to see the differences between all three. There's every chance they're negligible or even invisible. But adding TEA just felt like one more variable that I didn't need to compromise on when I could just use a bit more glycol.
 
@sufnturf

The concentration of AA does not have to be so high for FX-55 as to warrant using TEA.
I advice against using it. I experimented with it and the resulting negatives were inferior to those developed with FX-55 without TEA.
TEA is a base and a "amino alcohol" and has an effect on grain and contrast even in low concentrations.

The following formulation works perfectly well and comes very close to the original FX-55 formula.
The only difference is, that potassium ascorbate is the developing agent, instead of sodium ascorbate.
That does not matter though, as both are chemically equivalent if you factor in their molecular weight - which this formula does.

******************** PC Stock ********************

100 ml glycol at 50 C
12 g ascorbic acid (*1)
1 g Phenidone

******************** F Stock ********************

Warm water (70 C) : 700 ml - fill to 1 Litre after dissolving chemicals
Potassium carbonate anhydrous: 25 g to 28 g (*2)
Sodium bicarbonate : 1.5 g
Sodium sulfite anhydrous : 25 g
Sodium metabisulphite : 10 g

******************** FX-55 FILM DEVELOPER - FROM PC F Stock ********************

5 ml PC F Stock (0.05 g P, 0.6 g AA)
50 ml F Stock
Warm water (70 C) : top up to 500 ml (*3)

(*1) Takes a good while to dissolve, but it does so eventually. Do not heat above 70 degrees centigrade.

(*2) The original formula calls for 20 g of p. carbonate. When using ascorbic acid, some of the p. carbonate will react with it to form potassium ascorbate (our developing agent). The stoichiometric amount is 5 g of p. carbonate for 12 g or ascorbic acid. So we need a starting amount of 25g. However, in my case 27.5 g of p. carbonate works better. With 25g I found the activity and end contrast to be too low. This could be due to my p. carbonate not being lab grade 100% pure. Or because I like more contrast than the standard formula delivers.

(*3) Obviously use double the amount of stock solution if you make 1 litre of developer.

So if you go this route, start with 25g and test if the developer is active enough.
If it is not, then add a gram of potassium carbonate to the stock solution until you get the development time and contrast to your liking.
It should be in the range of 25 to 28 grams.

Shelf time is almost indefinite for both solutions.
Results are most likely identical to FX-55.
 

Gainer originally recommended a little TEA to aid in pH adjustment if using ascorbic acid instead of sodium ascorbate. John Finch increased the amount of it quite a lot, enough, possibly, to raise the pH and accordingly increase film speed and change other characteristics. Hence, perhaps, his claim of a significant speed increase.

I use Microphen when I need a bit more speed, but was wondering if FX-55 might be better (less grainy look?). It does have a lot more phenidone than PC-512.
 
The reason why Finch increased the TEA concentration, was indeed to up the PH. This was necessary, because he did not adjust the potassium carbonate concentration in the original formula to account for the fact, that some of it will be used up in a reaction with AA to create potassium ascorbate. I pointed this out to him and he confirmed. There is no need to add any TEA whatsover, if you start with extra potassium carbonate (from 25g to 27.5 g, depending on the contrast you want and the purity of the carbonate) in the original formula. See my formula above.
 

As ascorbic acid is cheaper and much easier to get than phenidone, I tried to keep phenidone to a minimum while still maintaining the ratio (and pH) that gives good film speed and very low fog (and meets solubility limits in propylene glycol). You can achieve the same things with more stuff mixed in and different ratios and pH. You can trade various properties for film speed (e.g. simplicity of formula, or grain, or development time, or fog, etc). It's all about which balance you prefer and what you want to spend or put effort into.
 

On first inspection of the comparison in #4 between FX55 and Xtol my impression is that the Xtol example somehow looks brighter and crisper The main central branch of the plant and the fruits lower down have a sort of "glow" in Xtol that they lack in FX55. FX55 seems to have produced a "flatter" image

I have moved on and then gone back to the pic several times and my first impression remains. However no-one else seems to have mentioned this aspect so maybe my VDU is set differently

pentaxuser
 

For me it was "six to one and a half dozen to the other"! I just didn't see enough difference to say one was better than the other.
 
John Wiegerink said:
For me it was "six to one and a half dozen to the other"! I just didn't see enough difference to say one was better than the other.
Click to expand...

Yes the difference is marginal and in terms of detail some parts of the FX55 neg seems to have slightly clear detail but in other areas Xtol had the edge.

Would I have seen any difference if I had looked at the two separately and a few minutes apart - possibly not

pentaxuser
 

I know I wouldn't have seen the difference, but looking through these old eyes an ugly milk maid looks like a Victoria's Secret model to me.
 
retina_restoration said:
Milkmaid's Secret sounds plausible to me lol
Click to expand...

Paul,
You get the models and I'll design the "leisure wear" and help with the photography end of it also. Milkmaid's Secret sounds like a perfect name for "leisure wear" aimed at farm girls or just plain down home country women. I want you to pick the models since these old eyes think any women 80 years old or less looks mighty fine.
 

There will always be some differences: trying to get both negatives to be exactly the same contrast requires some work, more than is usually given. Even if both are the same by some measurement, there can also be slight differences in toe shape etc etc. At my stage of life, very good is good enough. However I do have two new film developer formulas to try...
 
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