Salt (NaCl) as a fog reducer?

Here is more information about the particular sea salt and table salt I used in my caffenol-C concoction if anyone is interested (the weight conversions are based an some measurements I made just now):

[10ml = 13.3g]

I guess the most interesting thing is that the Sea Salt apparently had no Iodide.

Jeff

Sodium chloride at 30 g/litre does have a restraining effect. If it was benign and didn't then adding it to D23 wouldn't require a doubling in exposure and a similar increase in development time which is mirrored in the commercial developers that use (or usedas Microdol & Microdol-X are discontinued.

How ever it's acting differently as it promotes greater silver solvency during development and physivcal development, and can cause dichroic fogging with certain films

Typical Iodised table salt contains around 0.01-0.006% KI, (which some now think is to low), 30 grams of iodised salt contains between 35-60 times more iodide than is typically used in a litre of High Definition developers, but effects of the chloride may negate it's effects, especially as many modern films like Tmax are quite high in Silver Iodide anyway.

Ian

Denverdad said:

I guess the most interesting thing is that the Sea Salt apparently had no Iodide.

Jeff

Click to expand...

It contains Bromide which is an antifoggant.

PE

Photo Engineer said:

It contains Bromide which is an antifoggant.

PE

Click to expand...

It (the sea salt) doesn't list Bromide as an ingredient.

I think it is usually understood that "Sea Salt" is not necessarily limited to sodium chloride, and "salt" certainly is a generic term in all but the most common usage.

Some uses are vague... Magnesium chloride is found in raw mixtures of sea salt (called "nigari" in Japanese) and both Magnesium chloride and "Nigari" are often used for coagulating tofu from soy milk...

One should not think "salt" or "Sea Salt" means purified Sodium Chloride, even though it might to some companies.

The action (restraining etc.) depends on the interplay of several factors and so we should not be too hasty to make dogmatic statements.

Explanation may allude logic.

The bromide level isn't always given it can be around 0.02% However some inland seas can have a much higher content 0.2% because of more localised mineral deposits.

Sea waters not as homogeneous as you might think so there's some variations even between connected oceans/seas.

Ian

P.E., Ray, and Ian, thanks for the inputs. So it sounds like the presence of bromide (even though not listed as an ingredient) may be the responsible constituent in the sea salt? Seems plausible to me!

Also, I appreciate that the presence and concentration of minor constituents in NaCl products may vary; among the different types and brands, and possibly over time as well. But that is just like the coffee itself, for which you have to consider that different brands may yield different results due to the types of coffee beans they are made from (and probably a lot of other factors as well). Like it or not, that potential variability is just part of the game with caffenol developers. My strategy for maximizing consistency has been to choose the most commonly available major brands, thinking that they probably put more effort into providing a consistent product than the smaller brands - sort of the McDonald's effect you might say. Anyway, for me this means Folgers instant coffee, and Morton Iodized salt.