Modern Photography July 1968: Is this article really legitimate and honest?

[David Lyga]

"Kramer's Corner" was an old standby for ancient people like David Lyga.

Modern Photography's July 1968 issue states that B&W film developers can achieve greater resolution by adding potassium iodide. But I ask this: if this is so grand an idea, why have not the major manufacturers done this already? I leave up to you to come to meaningful conclusions on this topic. After all, I was only 18 when this was written!!! - David Lyga

 

[John Wiegerink]

"Kramer's Corner" was an old standby for ancient people like David Lyga.

Modern Photography's July 1968 issue states that B&W film developers can achieve greater resolution by adding potassium iodide. But I ask this: if this is so grand an idea, why have not the major manufacturers done this already? I leave up to you to come to meaningful conclusions on this topic. After all, I was only 18 when this was written!!! - David Lyga

Dave,
I think PE said that the latest films already have enough iodide incorporated in the emulsion so as not to need anymore. I guess adding more would have no direct impact on negative quality. I have not tried it one way or the other so I personally can't say. JohnW

 

[dE fENDER]

Is this article really legitimate and honest?

Yes.

Modern Photography's July 1968 issue states that B&W film developers can achieve greater resolution by adding potassium iodide. But I ask this: if this is so grand an idea, why have not the major manufacturers done this already?

High acutance developers have some disadvantages, so there is still exists other kinds. There are specialized high acutance developers which are preferrable than adding iodide salt to usual developer.

... I think PE said that the latest films already have enough iodide incorporated in the emulsion so as not to need anymore.

There are many purposes for iodide compounds in photography and all of them are different. The small quantity of silver iodide in emulsion will give extra speed. If the concentration of iodide will increase, a lot of problems will appear: 1. Pure iodide silver emulsion impossible to develop usual developing agents (without some additional organic compounds), photographer will have to use pyro developer heat to 65 C. 2. Emulsion with high quantity of iodide silver will be self-toning to green or olive color, see my photo below. It is not always desirable. 3. Emulsion with high quantity of iodide silver will tend to quickly give a lot of yellow fog (see edges at photo). 4. Emulsions with even moderate quantity of iodide silver will have a poor speed, even lower than pure chloride emulsions. 5. Emulsions with high iodide silver are very hard to fix properly, for proper fixation someone have to use potassium cyanide instead of thiosulfate with obvious disadvantages.

And none of the above is relevant to adding sodium or potassium iodide salts to developer.

I guess adding more would have no direct impact on negative quality. I have not tried it one way or the other so I personally can't say. JohnW

1% sodium iodide in developer will convert all other silver halide to silver iodide in a minute (see G.Haist book), and nothing will be developed. Less quantities of iodide (like in the article) will fully destroy the surface of silver halide crystals, so the will not surface development, only in deepness of the crystals. These two kind of development differs in some aspects.

So, the main purpose of such developers as in artice is obvious - the addition of sodium iodide is highly efficient age antifog agent, which should be used in pair with benzotriazole for very old photographic material, which a specially overexposed for such threatment.

Iodokont, a iodoclorobromide silver paper. There are no colored stuff here (like colored developer oxidation product as in pyro), the color appears due to the same reasons as in the Lipmann process.

 

[David Lyga]

Yes.


High acutance developers have some disadvantages, so there is still exists other kinds. There are specialized high acutance developers which are preferrable than adding iodide salt to usual developer.


There are many purposes for iodide compounds in photography and all of them are different. The small quantity of silver iodide in emulsion will give extra speed. If the concentration of iodide will increase, a lot of problems will appear: 1. Pure iodide silver emulsion impossible to develop usual developing agents (without some additional organic compounds), photographer will have to use pyro developer heat to 65 C. 2. Emulsion with high quantity of iodide silver will be self-toning to green or olive color, see my photo below. It is not always desirable. 3. Emulsion with high quantity of iodide silver will tend to quickly give a lot of yellow fog (see edges at photo). 4. Emulsions with even moderate quantity of iodide silver will have a poor speed, even lower than pure chloride emulsions. 5. Emulsions with high iodide silver are very hard to fix properly, for proper fixation someone have to use potassium cyanide instead of thiosulfate with obvious disadvantages.

And none of the above is relevant to adding sodium or potassium iodide salts to developer.


1% sodium iodide in developer will convert all other silver halide to silver iodide in a minute (see G.Haist book), and nothing will be developed. Less quantities of iodide (like in the article) will fully destroy the surface of silver halide crystals, so the will not surface development, only in deepness of the crystals. These two kind of development differs in some aspects.

So, the main purpose of such developers as in artice is obvious - the addition of sodium iodide is highly efficient age antifog agent, which should be used in pair with benzotriazole for very old photographic material, which a specially overexposed for such threatment.

Iodokont, a iodoclorobromide silver paper. There are no colored stuff here (like colored developer oxidation product as in pyro), the color appears due to the same reasons as in the Lipmann process.

Your dialog is well said and appreciated. I knew that there had to be a reason that such an addition might have consequences, deFENDER, and now I know. You state that, in conjunction with benzotriazole, sodium iodide synergizes its anti-aging effect with old materials.

I am not a chemist, but ask: Do you mean 'sodium' or 'potassium' iodide. Please clarify and thanks.

Oftentimes there are articles written which tell of only one side to an issue. Time usually takes care of reconciling that dichotomy, but this immediate case needed a bit more light cast upon it because it is rather arcane subject matter. I wanted to ask this question and let the matter be taken care of by someone who has much experience. You (and the others, as well), have helped greatly. - David Lyga

 

[AgX]

Iodokont ... it is a pity that here at Apug were are such ignorant on most soviet photo stuff.

 

[Photo Engineer]

Early emulsions were mainly AgBr (Silver Bromide) and if Iodide were present, it was buried in the grain or so dilute it had no substantial effect on much more than speed. Addiing any form of Iodide to the developer would cause immediate chemical reaction on the surface of the grains forming AgI (Silver Iodide) and then during development it would release Iodide imagewise causing an increase in edge effects and thus sharpness.

Today, we can manage the placement and release of Iodide and can make up to 10% Iodide emulsion as opposed to the 0.3 to 3.0% limits in the past. Thus, Iodide in developers with modern emulsions is not very effective.

In addition, Iodide ion can decompose in solution to form Iodate ion which is not as effective. Even so, some color developers use Iodide to balance the effects of having up to 9 layers present trying to compete, and the Iodide is used to balance the effects and "preseason" the developer. These color developers are not very prone to forming Iodates either.

PE

 

[Alan Johnson]

David, the second formula in Kramer's article to which you link is Geoffrey Crawley's FX-1. first published in BJP Jan 27 1961 p41.
I wrote to him in 2006 asking if the iodide still produced enhanced adjacency with newer films and he replied "There is indeed no point adding the iodide to FX-1 with modern films, this variant of Willi Beutler's famous developer was designed for the era of acutance films"
Way back I did a few tests confirming Kramer's conclusion that Plus-X is of the acutance type, as were all the Efke traditional films. No film of this type is presently on the market AFAIK.

 

[David Lyga]

PE and Alan Johnson, thank you both for the realistic feedback. I knew that there had to be an objective reason for the lack of an ongoing advisory to add this chemica to developers, Now I know. - David Lyga

 

[dE fENDER]

... I am not a chemist, but ask: Do you mean 'sodium' or 'potassium' iodide. Please clarify and thanks...

There is some difference in action of sodium and potassium iodides (due to different molar mass, for example), but I think, you can use any of them for this purpose, if you want. Potassium is more common in photographic recipes.

 

[dE fENDER]

Iodokont ... it is a pity that here at Apug were are such ignorant on most soviet photo stuff.

Well, it's not a pity. I found that only 1 package from about 7 is working, on the others the green tone left on the center of sheet as a irregular spots (if left at all). If you want to get green paper emulsion, you can quite easily made it by yourself from gelatine (I've use active one), potassium iodide, potassium bromide, table salt and silver nitrate.

Experiment with selfmade iodochlobromide emulsion:

 

[David Lyga]

error

 

[David Lyga]

Iodokont ... it is a pity that here at Apug were are such ignorant on most soviet photo stuff.

The 'ignorance' on 'Soviet photo stuff' was part of the political embargo game that the USA played to dissuade Americans from seeing ANYTHING desirable about ANYTHING the Soviet Union EVER brought forth. (we were drilled into seeing pure evil emanating from that huge country).

A similar scenario continues to this very day whereby Cuban merchandise (and, to boot, its exported doctors!!!) are not permitted to enhance the image that that country has within the Americas. This decision is utterly depraved and utterly childish, but we get away with it. We remain silent when our close 'friends', Mexico and Canada, do the complete opposite because we don't wish to draw attention upon our ongoing foolishness. - David Lyga