Caffenol high speed film question

[Fraunhofer]

I developed a roll of 120 Delta 3200 in Caffenol CL using 10g/l of iodized salt instead of KBr as restrainer. 80 minute semi-stand development. Tonality and grain in prints is OK, but there is a significant level of base fog. So my question: more iodized salt or should I switch to KBr? If so, how much?

 

[JW PHOTO]

Iodized salt has far to much iodide in it for your use as a film developer. Kbr is a far, far better choice or Benzotriazole.

 

[Gerald C Koch]

Sodium iodide is unstable disproportionating into elemental iodine and sodium iodate. Any sample therefore has a varying and unknown amount of iodide. Then too modern emulsions contain a lot of iodine so iodide is less effective as a restrainer. Forget using it with any developer.

 

[anfenglin]

That and i noticed massive base fog in a delta 3200, no matter the developer.
I use caffenol a lot and always use KBr, no matter the film speed.

 

[removed account4]

you should ask this question at caffenol blogs, not here.

you will get more answers from more people who actually use this formula/these additions to caffenol.
unlike a lot of the apug population, more people there use caffenol, and most likely in the application you are using it for.
sure, i'll throw an answer into the ring
but here's a disclaimer, i've never used the various formulae ( cl, cd, cc, c-ya ),
i just my own lazy forumla and it doesn't include salt or adding KBr separately,
instead, it involves thowing a 20cc spike of either stock dektol /D72 or ansco 130 into your coffee,
i've thrown in used/SPENT dektol/d72 / ansco 130 and it works well too.
been using this forumla for 10 years now, and i've used it with ALL speed film, works great.
but unfortunately, my suggestions no help to you ...

good luck and have fun with your caffenol ( and post your results in the coffee developer group ) !
john

 

[Fraunhofer]

Sodium iodide is unstable disproportionating into elemental iodine and sodium iodate. Any sample therefore has a varying and unknown amount of iodide. Then too modern emulsions contain a lot of iodine so iodide is less effective as a restrainer. Forget using it with any developer.

So you are saying (it's a while since I took chemistry 101) due to the formation of sodium iodate it is basically not possible to predict the amount of iodine ions resulting from a given amount of iodized salt?

 

[Gerald C Koch]

So you are saying (it's a while since I took chemistry 101) due to the formation of sodium iodate it is basically not possible to predict the amount of [sic] iodine ions resulting from a given amount of iodized salt?

Yes the amount of iodide present in the salt can no longe be known.

However, the second part of my post was that you shouldn't be using iodide in the first place. It isn't useful with modern films.

 

[pgomena]

My recent tests with Caffenol and HP5+ and FP4+ showed 1 gram per liter of potassium bromide worked perfectly. That's about a scant half-teaspoon if you don't have a scale handy.

 

[Fraunhofer]

Yes the amount of iodide present in the salt can no longe be known.

However, the second part of my post was that you shouldn't be using iodide in the first place. It isn't useful with modern films.

Ah, the finer details of chemical nomenclature, I have to admit I failed my chemistry course the first time and barely passed the second time... In any case KBr arrived in the mail on Friday.

 

[Gerald C Koch]

Ah, the finer details of chemical nomenclature, I have to admit I failed my chemistry course the first time and barely passed the second time... In any case KBr arrived in the mail on Friday.

Perhaps this may help. Table salt (sodium chloride) is a vital nutrient. However the elements from which it is composed (sodium and chlorine) are very dangerous. Going the other way. Nitrogen is all around us comprising roughly 80% of our atmosphere. It behaves almost like an inert gas like helium. However many of its compounds like lead azide Pb(N3)2 are violently explosive. Big difference between an element and its ion(s).